Two-stage converter using low permeability magnetics
Granted 4 Oct 2005 · 2 office actions
Current assignee: Saturn Electronics & Engineering, Inc. · originally OPS Power LLC
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Attorney: Attorney · Log in to unlock
Inventors: Jeffrey Michael Buske, Christopher Allen Riggio, David R. Thompson, Nathan J. Hunter +2 · Examiner: Jeffrey Sterrett · AU 2838 · TC 2800
Life of the application
13 dated eventsAbstract
The use of low permeability magnetic material (NSME) with the disclosed design strategies form a two-stage isolated output converter system with the distinct advantages of superior density, efficiency, thermal operating bandwidth, service life, transient survival, and form factor flexibility over the prior art. These improvements are realized by, optimized application of NSME, efficient rectifying flyback management techniques, inclusion of switching buffers that substantially reduce switching losses. The instant invention provides power factor correction, output regulation, inrush limiting, over voltage, over current, over temperature, and transient protection, multi-converter load sharing, hot swapability, and fault signals. The disclosed system is designed, specified, and certified to function from −40 deg. C. to +65 deg. C. from a 180 vac to 264 vac 50/60 Hz input line and supports 1000 watts of output or 600 watts from 90 vac to 120 vac 50/60 Hz line input at greater then 0.95 power factor and features a packaged power density of 14 watts per cu. in. at high line.
Description
38 parts›CROSS REFERENCE APPLICATION
This application incorporates by reference U.S. Pat. No. 6,272,025 issued Aug. 7, 2001.
›FIELD OF INVENTION
The present invention relates to high wattage multi stage isolated output AC/DC power factor corrected converters and power supplies utilizing electrical, mechanical, and packaging design innovations that compliment the use of individual or distributed NSME resulting in efficient operation, high wattage density, rugged transient protection, no thermal derating, fan-less thermal transfer, and long service life.
›BACKGROUND OF THE INVENTION
There are several basic single or combination topologies commonly used to implement switching converters.
One of the topologies is the push-pull converter. The output signal is derived from the output of an IC network that switches the transistors alternately “on” and “off”.
High frequency square waves on the transistor output drive the magnetic element into AC (alternating current) bias. The isolated secondary outputs a wave that is rectified to produce DC (direct current). Push-pull converters generally have more components as compared to other topologies. The push-pull approach makes efficient use of the magnetic element by producing AC bias, but suffers from high parts count, thermal derating, oversized magnetics, and elaborate core reset schemes.
The destructive fly-back voltages occurring across the switches are controlled through the use of dissipative snubber networks positioned across the primary switches. Another of the topologies is the forward converter. When the primary of the forward converter is energized, energy is immediately transferred to the secondary winding. In addition to the aforementioned issues the forward converter suffers from inefficient (dc bias) use of the magnetic element. The prior art power supplies generally use high permeability gapped ferrite magnetic elements. These are well known in the art and are widely used. The magnetics of the prior art power supplies are generally designed for twice the required power rating and require complex methods to reset and cool the magnetic elements resulting in increased installed costs, size, complexity and limited operating temperatures. This is because high permeability magnetic elements saturate during operation producing heat in the core, which increases permeability and lowers the saturation threshold. This produces runaway heating, current spikes and/or large leakage currents in the air gap, reduced efficiency, and ultimately less power at higher temperatures and/or high load. The overall effects are, lower efficiency, lower power density, and forced air/heatsink dependant supplies that require over-rated ferrite magnetic elements for a given output over time, temperature, and loading.
›IMPROVEMENTS
The combined improvements of the invention translate to higher system efficiencies, higher power densities, lower operating temperatures, and, improved thermal tolerance thereby reducing or eliminating the need for forced air cooling per unit output. The non-saturating magnetic properties are relatively insensitive to temperature (see FIG. 17 ), thus allowing the converter to operate over a greater temperature range. In practice, the operating temperature for the NSME is limited to 200 C by wire/core insulation; the non-saturating magnetic material remains operable to near its Curie temperature of 500 C.
What are needed are converters having circuit strategies that make advantageous use of individual and distributed non-saturated magnetic elements.
What are needed are two stage power factor corrected converters that regulate a constant frequency constant duty cycle isolated output stage from the non-isolated input stage.
What are needed are converters that are electrically, mechanically, and physically optimized to provide superior density, efficiency, longevity and manufacturability using NSME's.
What are needed are converters that incorporate efficient silicon carbide diode flyback management techniques to rectify excessive leading edge node voltages across output diodes.
What are needed are converters having buffer circuits that provide fast, low impedance critically damped switching of the main FETs.
What are needed are converters that meet or exceed class B conducted EMI and other applicable certification requirements.
What are needed are high MTBF converters tolerant of line transients and harsh thermal environments.
The present invention addresses these and more.
›SUMMARY OF THE INVENTION
The main aspect of the present invention is to implement a two stage high wattage, density, and efficiency isolated output converter having circuit strategies that make advantageous use of individual and distributed NSME for the achievement of the key performance enhancements disclosed herein.
Another aspect of the present invention is to provide a converter design that utilizes a FET drive technique consisting of an ultra fast, low RDS (on) N-channel FET for charging the main FET gate and an ultra fast P-channel transistor for discharging the main FET gate.
Another aspect of the present invention is to provide converters that incorporate output additive silicon carbide diode flyback management techniques to rectify excessive node voltages across output diodes.
Another aspect of the present invention is to provide a converter having core (flux) synchronized zero crossing frequency modulation.
Another aspect of the present invention is to provide a high power factor to the AC line.
Another aspect of the present invention is to provide protection from high voltage (input line) transients.
Another aspect of the present invention is to combine low permeability magnetics advantageously with the other electrical, mechanical, and packaging aspects.
Another aspect of the present invention is the combination of a power factor correcting NSME regulator stage with a constant frequency constant duty cycle NSME isolation stage.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
›BRIEF DESCRIPTION OF THE DRAWINGS · 1 of 2
FIGS. 1 and 1A is a schematic diagram of a two-stage power factor corrected AC to DC isolated output converter embodiment of the invention.
FIG. 2 is a schematic diagram of a single stage DC to AC converter embodiment with isolated output sub-circuit DCAC 1 .
FIGS. 3 and 3A is a schematic diagram of a three stage AC to DC isolated output converter embodiment of the invention.
FIG. 4 is a schematic diagram of a power factor corrected single stage AC to DC converter sub-circuit ACDFPF.
FIG. 4A is a schematic diagram of an alternate power factor controller with load sharing converter sub-circuit ACDFPF 1 .
FIG. 5 is a graph comparing typical winding currents in saturating and non-saturating magnetics of equal inductance.
FIG. 6 is a schematic for a non-isolated low side switch buck converter sub-circuit NILBK.
FIG. 7 is the schematic for a tank coupled single stage converter sub-circuit TCSSC.
FIG. 8 is a schematic for a tank coupled totem pole converter sub-circuit TCTP.
FIG. 9 is a block diagram for a single stage non-isolated DC to DC boost converter NILSBST.
FIG. 10 is a schematic for a two stage isolated DC to DC boost controlled push-pull converter BSTPP.
FIG. 11 is a graph of permeability as a function of temperature for typical prior art magnetic element material.
FIG. 12 is a graph of flux density as a function of temperature for typical prior art magnetic element material.
FIG. 12A is a graph of magnetic element losses for various flux densities and operating frequencies typical of prior art magnetic element material.
FIG. 13 is a graph showing standard switching losses.
FIG. 14 is a graph showing lower switching losses of the invention.
FIG. 15A is a graph of the magnetization curves for H Material.
FIG. 16 is a graph of magnetic element losses for various flux densities and operating frequencies of the NSME material.
FIG. 17 is a graph of permeability as a function of temperature for the NSME.
FIG. 18 is a schematic representation of the boost NSME sub-circuit PFT 1 .
FIG. 18A is a schematic representation of the NSME sub-circuit PFT 1 A.
FIG. 18B is a schematic representation of the non-saturating two terminal NSME sub-circuit BL 1 .
FIG. 18C is a schematic diagram of the NSME implemented as distributed magnetic assembly PFT 1 D.
FIG. 19 is a schematic representation of the push-pull NSME sub-circuit PPT 1 .
FIG. 19A is a schematic representation of the alternate push-pull NSME sub-circuit PPT 1 A.
FIG. 20 is a schematic diagram of the NSME input transient protection and line filter sub-circuit LL.
FIG. 20A is a schematic showing an alternate line filter LF.
FIG. 21 is a schematic diagram of the alternate NSME input transient protection and line filter sub-circuit LLA.
FIG. 22 is a schematic diagram of the AC line rectifier sub-circuit BR.
FIG. 23 is a schematic diagram of the power factor controller sub-circuit PFA.
FIG. 24 is a schematic diagram of the alternate power factor correcting boost control element sub-circuit PFB.
FIG. 25 is a schematic diagram of the output rectifier and filter sub-circuit OUTA.
FIG. 25A is a schematic diagram of an alternate rectifier sub-circuit OUTB.
FIG. 25B is a schematic diagram of an alternate final output rectifier and filter sub-circuit OUTBB.
FIG. 26 is a schematic diagram of the floating 18_Volt DC control power sub-circuit CP.
FIG. 26A is a schematic diagram of and alternate 18_Volt DC control power sub-circuit CP 1 .
FIG. 26B is a plot of VCC control voltage as a function of output power in watts during operation of sub-circuit ACDCPF 1 (FIG. 4 A).
FIG. 27 is a schematic diagram of the alternate floating 18_Volt DC push-pull control power sub-circuit CPA.
FIG. 28 is a schematic diagram of the over temperature protection sub-circuit OTP.
FIG. 29 is a schematic diagram of the high-speed low impedance buffer sub-circuit AMP, AMP 1 , AMP 2 and AMP 3 .
FIG. 30 is a schematic diagram of the main switch snubber sub-circuit SN.
FIG. 30A is a schematic diagram of the main switch rectifying diode snubber sub-circuit DSN.
FIG. 30B is a schematic diagram of the main switch snubber sub-circuit SNBB.
FIG. 31 is a schematic diagram of the alternate snubber sub-circuit SNA.
FIG. 32 is a schematic diagram of the mirror snubber sub-circuit SNB.
FIG. 33 is a schematic diagram of the pulse-width/Frequency modulator sub-circuit PWFM.
FIG. 34 is an oscillograph of node voltages measured during operation of sub-circuit PWFM (FIG. 33 ).
FIG. 35 is an oscillograph of the primary tank voltage measured during operation of sub-circuit TCTP (FIG. 8 ).
FIG. 36 is a schematic diagram of the non-isolated 18-Volt DC control power sub-circuit REG.
FIG. 37 is a schematic for a non-isolated high-side switch buck converter sub-circuit HSBK.
FIG. 38 is a schematic for the low-side buck regulated two-stage converter embodiment with isolated push-pull output sub-circuit LSBKPP.
FIG. 39 is a schematic for an alternate isolated two-stage low-side switch buck converter sub-circuit LSBKPPBR.
FIG. 40 is a schematic diagram of the over voltage feed back sub-circuit IPFFB.
FIG. 40A is a schematic diagram of the non-isolated boost output voltage feedback sub-circuit FBA.
FIG. 40B is a schematic diagram of the isolated output voltage feedback sub-circuit IFB.
FIG. 40C is a schematic diagram of the alternate isolated over voltage feedback sub-circuit IOVFB.
FIG. 40D is a schematic diagram of and alternate the non-isolated boost output voltage feed back sub-circuit FBD.
FIG. 41 is a schematic diagram of the non-isolated output voltage feedback sub-circuit FBI.
FIG. 41A is a schematic diagram of an alternate non-isolated feedback sub-circuit FB 2 .
FIG. 42 is a schematic diagram of an over voltage protection sub-circuit OVP.
FIG. 42A is a schematic diagram of the isolated over voltage feedback sub-circuit OVP 1 .
FIG. 42B is a schematic diagram of the over voltage protection sub-circuit OVP 2 .
FIG. 42C is a schematic diagram of the isolated over voltage feedback sub-circuit OVP 3 .
FIG. 43 is a schematic diagram of the Push-pull oscillator sub-circuit PPG.
›BRIEF DESCRIPTION OF THE DRAWINGS · 2 of 2
FIG. 44 is a schematic diagram of the soft start/inrush current limit sub-circuit SS 1 .
FIG. 44A is an oscillograph of line current and output voltage during operation of sub-circuit SS 1 (FIG. 44 ).
FIG. 45 is a schematic diagram of the fast start sub-circuit FS 1 .
FIG. 45A is an oscillograph of sub-circuit FS 1 during operation of sub-circuit SS 1 (FIG. 44 ).
FIG. 46 is a schematic diagram of an alternate transient protection sub-circuit TRN.
FIG. 46A is a schematic diagram of an alternate transient protection sub-circuit for external application TRNX.
FIG. 46B is an oscillograph of the converter operation during a high voltage transient event.
FIG. 47 is a signal flow diagram teaching the load sharing system.
FIG. 47A is an alternate signal flow diagram teaching the load sharing system.
FIG. 48 is an isometric view of the ITMS (integrated thermal management system).
FIG. 49 is a isometric view of the thermally conductive block 4900 .
FIG. 50 is a detailed view of high performance, multiple pin, high-current terminals.
FIG. 51 is another example of how a metal cup and thermally conductive material is used to remove heat from a magnetic element.
FIG. 52 is the top view of the alignment header 5200
FIG. 53 is a detailed view of thermal compression spring clip 5300 .
FIG. 54 is a detailed view of the thermal compression clamp 5400 .
FIGS. 55 and 55A is a schematic diagram of the preferred embodiment two-stage power factor corrected AC to DC isolated output converter of the invention.
FIG. 56 is a schematic diagram of the preferred embodiment non-isolated power factor corrected AC to DC converter of the invention.
FIG. 57 is the schematic of the preferred embodiment inter-stage inrush limit sub-circuit ISIR.
FIG. 58 is the schematic of the preferred embodiment of the output controller sub-circuit OUTC.
FIG. 59 is a schematic diagram of the preferred embodiment AC inrush limiter sub-circuit ACIR of the invention.
FIG. 60 is the schematic of the preferred embodiment of the sub-circuit ACOKC.
FIG. 61 is a schematic representation of the boost NSME sub-circuit PFT 2 .
FIG. 62 is a schematic diagram of the improved NSME input transient protection and line filter sub-circuit LFB.
FIG. 63 is a schematic diagram of the preferred embodiment power factor correcting boost controller of the isolated two-stage converter sub-circuit PFC.
FIG. 64 is a schematic diagram of the preferred embodiment power factor correcting boost control sub-circuit PFD.
FIG. 65 is a schematic diagram of the preferred embodiment three output isolated DC control power sub-circuit CP 3 .
FIG. 66 is a schematic diagram of the preferred embodiment DC control sub-circuit CP 2 .
FIG. 67 is a schematic diagram of the preferred embodiment silicon carbide diode snubber sub-circuit SCIN of the invention.
FIG. 68 is a schematic diagram of the preferred embodiment non-isolated boost output voltage feed back sub-circuit VFBI.
FIG. 69 is a schematic diagram of the preferred embodiment push-pull oscillator sub-circuit PPGA.
FIG. 70 is a schematic diagram of the main switch snubber sub-circuit SNDD.
Before explaining the disclosed embodiments of the present invention in detail, it is to be understood that: The invention is not limited in its application to the details of the particular arrangements shown or described, since the invention is capable of other embodiments.
The expression “distributed magnetic(s)” refers to the configuration of multiple magnetic elements that share a single series coupled primary winding to induce isolated output currents from multiple series or parallel secondary windings.
Also, the terminology used herein is for the purpose of description not limitation.
›DESCRIPTION OF THE PREFERRED EMBODIMENT
In this and other descriptions contained herein, the following symbols shall have the meanings attributed to them: “+” shall indicate a series connection, such as resistor A in series with resistor B shown as “A+B”. “∥” Shall indicate a parallel connection, such as resistor A in parallel with resistor B shown as “A∥B”.
FIGS. 55 and 55A is a schematic diagram of the preferred two stage power factor corrected AC to DC converter. The invention is comprised of line protection filter sub-circuit LFB ( FIG. 62 ) and ac line monitor sub-circuit ACOKC (FIG. 60 ). A power factor corrected regulated boost stage with sub-circuits PFC (FIG. 63 ), snubber sub-circuit SCIN (FIG. 67 ), snubber sub-circuit SNBB (FIG. 30 B), magnetic element sub-circuit PFT 2 (FIG. 61 ), Bias supply sub-circuit CP 3 (FIG. 65 ), buffer sub-circuit AMP (FIG. 29 ), AC inrush limit sub-circuit ACIR (FIG. 59 ), voltage feedback sub-circuit VFBI (FIG. 68 ). Filter capacitor C 1 , PFC capacitor C 2 , flyback diode D 4 , switch transistor Q 1 , hold up capacitors C 17 and C 16 , and resistor R 17 . An efficient push-pull isolation stage with inrush limit sub-circuits ISIR (FIG. 57 ), PPGA (FIG. 69 ), AMP 1 (FIG. 29 ), AMP 2 (FIG. 29 ), and snubber SNDD (FIG. 70 ), resistor Rload, transistors Q 6 and Q 9 , magnetic element PPT 1 (FIG. 19 ), rectifier OUTA ( FIG. 25 ) and output controller OUTC (FIG. 58 ).
FIG. 55-55A Table Element Value/part number C1 0.01 uf C2 1.8 uf R2 100k ohms D4 8 A, 600 V D460 MR760 Q1 IRFP 460 C17 680 uf C16 680 uf R17 375k ohms Q6 FS 14SM-18 A Q9 FS 14SM-18 A
In the two-stage converter the primary side voltage to the second push-pull output stage is modulated by the power factor corrected input (boost) stage. Each stage can comprise of individual and distributed NSME. Although the following description is in terms of particular converter topologies, i.e., flyback controlled primary and constant duty cycle push pull secondary, number of outputs, the style, and arrangement of the several topologies are offered by way of example, not limitation. In addition non-saturating magnetics BL 1 , PFT 2 , and PPT 1 may be implemented as distributed NSME. As an example PFT 2 is shown as a distributed magnetic PFT 1 A (FIG. 61 ). Distributed magnetics enable advantageous high voltage converter design variations that support form factor flexibility and multiple parallel secondary outputs from series coupled voltage divided primary windings across multiple NSME. The positive of the hold-up capacitor(s) [C 17 ∥C 16 ] is connected and inrush and shut down sub-circuit IRIR. This allows the power from the forward converter to be applied in a controlled way to the push pull converter. In this way temporary overload, over temperature faults may be recovered from and normal operation may resume after the fault is removed. This eliminates chance of damaging Q 6 and Q 9 during after recovering from a fault. AC line L 2 is connected through inrush limit sub-circuit ACIR ( FIG. 59 ) to improved line filter sub-circuit LFB (FIG. 62 ). AC/earth ground is connected to node LLO. The filtered and rectified voltage appears on node B+ the return line to BR−. The positive haversine appearing on node B+ of sub-circuit LFB connects to sub-circuit CP 3 pin B+, sub-circuit PFT 2 pin P 1 B, sub-circuit SNBB pin SNL 1 and first side of capacitor C 2 . The raw haversine appearing on node BR+ connects to anode of series transient diode D 460 to node PF+. During normal operation transient protection diode D 460 is reverse biased due to the action of the boost. With the application of a high voltage event HV 1 ( FIG. 46B ) of any polarity to the AC line, the rectified event appears on node BR+, also shown in oscillograph G 463 (FIG. 46 B). If the transient voltage exceeds the storage capacitor voltage at C 16 , C 17 ( FIG. 55 ) or C 417 (FIG. 56 ), D 460 is forward biased transferring the energy to storage capacitor. Common art transient methods shunt the energy into spark gaps or MOV type devices. These devices suffer from limited life cycles, excessive leakage currents or a catastrophic failure. With proper component selection very large transients may be absorbed without exceeding device ratings. Thus insuring high reliability with minimal parts counts and cost. The instant invention is adaptable to other offline converters having a storage capacitor maintained (boosted) above the rectified peak line voltage. This topology will work with positive or negative reference converters. Output node VCC 1 of CP 3 connects to pins PFA+ of sub-circuit PFC (FIG. 63 ), pin VCC 1 of sub-circuit ACOKC ( FIG. 60 ) and gate buffer sub-circuit AMP pin GA+. Bias supply CP 3 provides start control power to the system. Node S 1 L from PFT 2 is connected to node PFVC of sub-circuit PFC. The zero crossings of the core are sensed when the voltage at S 1 L is 0-volts. The core zero crossings are used to reset PFC and start a new cycle. The positive node of the DC side of bridge B+ is connected through capacitor C 2 to BR−. Capacitor C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor while reducing line harmonics and EMI. Primary of NSME sub-circuit PFT 2 ( FIG. 61 ) pins P 1 A connects to pin SNL 2 of snubber sub-circuit SNBB ( FIG. 30B to sub-circuit SCIN pin SNL 2 and connects drain of Q 1 . The return line for the rectified AC power BR− is connected to the following pins; BR−of sub-circuit ACOKC, sub-circuit PFC pin BR−, sub-circuit AMP, AMP 1 and AMP 2 pin GA 0 , output switch Q 1 source, capacitor C 2 , sub-circuit CP 3 pin BR−, sub-circuit PFT 2 pin S 1 H, PPGA (FIG. 69 ), capacitor [C 16 ∥C 17 ∥resistor R 17 ], transistor Q 6 source, transistor and Q 9 source. The drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit SCIN pin SNL 2 , sub-circuit PFT 2 pin P 1 A and sub-circuit SNBB pin SNL 2 . Snubber networks SNBB and SCIN reduce the high voltage stress to Q 1 and recover fly back energy. The improved zero hold flyback diode SCIN improves converter efficiency approx 0.3% by recovering more flyback energy than D 4 alone. Line coupled, power factor corrected boost regulated output voltage of the AC to DC converter stage appears on node PF+. The regulated boost output PF+ connects to the following; sub-circuit SNBB pin SNOUT, sub-circuit SCIN pin SNOUT, cathode of transient diode D 460 and diode D 4 cathode. Node PF+ also connects on FIG. 55A to capacitors [C 16 ∥C 17 ∥R 17 ], sub-circuit VFBI ( FIG. 68 ) pin PF+ and to input of sub-circuit ISIR ( FIG. 57 ) pin PF+. Sub-circuit ISIR pin PPIN connects to sub-circuit PPT 1 ( FIG. 19 ) pin P 2 CT, snubber sub-circuit SNDD ( FIG. 70 ) pin SNA 3 , and second snubber SNDD pin SNA 3 and input of sub-circuit CP 3 pin PPIN. Bias supply CP 3 pin OUTS− is connected to ISIR pin OUTS− and OUTC pin OUTS−. Bias supply CP 3 pin VCC 3 is connected to OUTC pin VCC 3 . Bias supply CP 3 pin VCC 2 is connected to ISIR pin VCC 2 , buffer sub-circuit AMP 1 pin GA+, buffer sub-circuit AMP 2 pin GA+ and sub-circuit PPGA pin PPG+. Sub-circuit PFC using the AC line phase, load voltage, and magnetic element feedback, generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFC ( FIG. 63 ) is connected to the input of buffer amplifier pin GA 1 of sub-circuit AMP 1 . Buffered high-speed gate drive output pin GA 2 of sub-circuit AMP is connected to gate of switch FET Q 1 . The buffering provided by AMP shortens switch Q 1 ON and OFF times greatly reducing switch losses (see FIGS. 13 & 14 ). In the event of an over temperature condition (the case of Q 1 reaches approximately 105C) TS5728 ( FIG.57 ) opens removing power to node PPIN output stage safely shutting down the push pull stage. Normal operation resumes after the switch temperature drops 20-30 deg. C. closing TS5728. Voltage feed back sub-circuit VFIB pin PF 1 is connected to sub-circuit PFC pin PF 1 . AC monitoring sub-circuit ACOKC Pin ACOK is connected to sub-circuit PFC pin ACOK. In the event of a low line voltage condition ACOK is set low stopping the boost action of PFC. Constant frequency/duty-cycle non-overlapping two-phase generator sub-circuit PPGA ( FIG. 69 ) generates the drive for the push-pull output stage. Phase one output pin PHI is connected to sub-circuit AMP 1 pin GA 1 , second phase output pin PH 2 is connected to sub-circuit AMP 2 pin GA 1 . Output of amplifier buffer sub-circuit AMP 1 pin GAP 2 connects to gate of push-pull output switch Q 6 . Output of amplifier buffer sub-circuit AMP 2 pin GAP 2 connects to gate of push-pull output switch Q 9 . The buffering currents from AMP 1 and AMP 2 provide fast, low impedance critically damped switching to Q 6 and Q 9 greatly reducing ON-OFF transition time and switching losses. Drain of transistor Q 6 is connected to snubber network sub-circuit SNDD pin SNA 1 and to non-saturating center tapped primary magnetic element sub-circuit PPT 1 pin P 2 H. Drain of transistor Q 9 is connected to snubber network sub-circuit SNDD ( FIG. 70 ) pin SNA 1 and sub-circuit PPT 1 pin P 2 L. Isolated output of NSME sub-circuit PPT 1 pin SH connects to Pin C 7 B of rectifier sub-circuit OUTA (FIG. 25 ), pin SL connects to sub-circuit OUTA C 8 B. Center tap of PPT 1 pin SCT is the output return or negative node OUT− it connects to sub-circuit OUTA pin OUT− and output controller sub-circuit OUTC ( FIG. 58 ) pin OUT−. Converter positive output from sub-circuit OUTA pin OUT+ is connected to RLOAD and sub-circuit OUTC pin OUT+. Second side of RLOAD connects to sub-circuit OUTC pin OUTS−. Magnetic element sub-circuit PPT 1 provides galvanic isolation and minimal voltage overshoot and ripple in the secondary thus minimizing filtering requirements of the rectifier sub-circuit OUTA. Sub-circuit VFBI provides high-speed feedback to the AC DC converter, the speed of the boost stage provides precise output voltage regulation and active ripple rejection. Output control OUTC also protects the load and converter during under and over voltage or current faults. This configuration provides power factor corrected input transient protection, rapid line-load response, excellent regulation, isolated output and quiet efficient operation at high temperatures.
›ADDITIONAL EMBODIMENTS · 1 of 30
FIG. 56 is a schematic diagram of auto load leveling power factor corrected converter ACDCPF 2 also referred to as power factor connecting flyback converter (PFCFC). The invention is comprised of line filter sub-circuit LF (FIG. 20 A), transient diode D 460 , power factor corrected regulated boost stage with sub-circuits PED (FIG. 64 ), zero delay flyback diode sub-circuit SCIN (FIG. 67), or snubber sub-circuit SNBB (FIG. 30 B), magnetic element sub-circuit PFT 1 A (FIG. 18 A), sub-circuit CP 2 (FIG. 66 ), buffer circuit AMP (FIG. 29 ), over temperature sub-circuit OTP (FIG. 28 ), and voltage feedback sub-circuit FBD (FIG. 68 ), Start resistor R 2 PFC capacitor C 2 , switch transistor Q 1 and hold up capacitor C 417 .
Table FIG. 56 Value/part Element number C2 1.8 uf Q1 ATP5020BVR D460 MR 760 C417 330 uf R345 1 MEG ohms R2 100K ohm
AC line is connected to sub-circuit LF ( FIG. 20A ) between nodes LL 1 and LL 2 . AC/earth ground is connected to node LL 0 . The filtered and rectified AC line appears on pin BR+ of sub-circuit LF connects to anode of transient diode D 460 . Cathode of diode D 460 connects to node PF+ and main storage capacitor C 417 . The line voltage is full-wave rectified converted to a positive haversine appearing on node B+ of sub-circuit LF (FIG. 20 A). Node B+ of filter sub-circuit LF is connected to input pin BR+ of PFD (FIG. 64 ), positive of capacitor C 2 , pin PB 1 of sub-circuit PFT 1 A pin B+. Capacitor C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor and EMI. Node PFA+ of CP 2 connects to pin PFA+ of power factor controller sub-circuit PFD (FIG. 64 ), pin GAP of over temperature sub-circuit OTP( FIG. 28 ) and start resistor R 2 . Start resistor R 2 provides start up power until the converter is at full power. It also provides restart in the event of an extended loss of boost. Node S 1 H from PFT 1 A is connected to node PFVC of sub-circuit PFD and to node CT 1 A of sub-circuit CP 2 . The zero crossing of the core bias are sensed when the voltage at SH 1 is zero. The core zero crossings are used to reset U 2413 ( FIG. 64 ) and start a new cycle. Primary of NSME sub-circuit PFT 1 A ( FIG. 18A ) pin P 1 A connects to pin SNL 2 of snubber sub-circuits SNBB ( FIG. 30B ) or SCIN ( FIG. 67 ) and drain of Q 1 . Sub-circuit PFD pin BR+ connects to node B+. Return line for the rectified AC power BR− is connected to the following pins; BR− of sub-circuit LF, sub-circuit PFD pin BR−, sub-circuit AMP pin GA 0 , sub-circuit CP 2 pin BR−, source of output switch Q 1 , second side of capacitors C 417 and C 2 . Drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit PFT 1 A pin P 1 A and snubber sub-circuits SNBB and SCIN pin SNL 2 . Switch protection is achieved by adding sub-circuit SNBB ( FIG. 30B ) or SCIN ( FIG. 67 ) in parallel flyback diode D 4 . Sub-circuit SNBB and SCIN reduce the high voltage stresses to Q 1 until flyback diode D 4 begins conduction. Regulated output voltage of the converter appears on node PF+. The regulated boost output PF+ connects to the following; sub-circuit SNBB and SCIN pin SNOUT, diode D 460 cathode, capacitor C 417 , and diode D 4 cathode. Magnetic element winding node S 1 L of sub-circuit PFT 1 A is connected to CP 2 pin CT 2 A. During normal operation transient protection diode D 460 is reverse biased due to the action of the boost. With the application of a high voltage event HV 1 of any polarity to the AC line, the rectified event appears on node BR+, also shown in oscillograph G 463 (FIG. 46 B). If the transient voltage exceeds the storage capacitor voltage at C 17 ( FIG. 55 ) or C 417 (FIG. 56 ), D 460 is forward biased transferring the energy to storage capacitor. Common art transient methods shunt the energy into spark gaps or MOV type devices. These devices suffer from limited life cycles, excessive leakage currents or a catastrophic failure. With proper component selection very large transients may be absorbed without exceeding device ratings. Thus insuring high reliability with minimal parts counts and cost. The instant invention is adaptable to other offline converters having a storage capacitor maintained (boosted) above the rectified peak line voltage. This topology will work with positive or negative reference converters. Magnetic element winding node S 1 CT of sub-circuit PFT 1 A is connected to CP 2 pin CT 0 . Sub-circuit PFD using the phase of the AC line, and load voltage generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFD is connected to the input of buffer amplifier pin GA 1 of sub-circuit AMP 1 (FIG. 29 ). Buffered high-speed gate drive output pin GA 2 of sub-circuit AMP is connected to gate of main switch Q 1 . The buffering provided by AMP shortens switch Q 1 “ON” and “OFF” times greatly reducing switch losses. Over temp sub-circuit OTP ( FIG. 28 ) pin TS+ is connected to sub-circuit AMP pin GA+. Thermal switch THS 1 ( FIG. 28 ) is thermally connected to Q 1 . In the event Q 1 reaches approximately 105 C THS 1 opens removing power to sub-circuit AMP, safely shutting down boost operation. Normal operation resumes after the switch temperature drops 20-30C closing THS 1 . Sub-circuit feedback network FBD ( FIG. 40D ) pin PF 1 is connected to sub-circuit PFD pin PF 1 . This feedback is non-isolated; network values are selected for a substantially constant 385-Volt output at PF+ relative to BR−. The high-voltage haversine from the rectifier section pin B+ is connected to sub-circuit PFD pin BR+ is used to make the converter ACDCPF 2 appear resistive to the AC line. The regulated high voltage output of this converter may be used use with one or more external converters connected in parallel. A unique feature of the converter ACDCPF 2 is the automatic load-sharing feature. Where the output of ACDCPF 2 varies as a function of load as shown in FIG. 66 . Load leveling resistor connected between nodes VCC and PF 1 regulates the output voltage lower as the load/boost increases. This unique action allows units to be operated in parallel without the typical master slave connections. In this way the lightly loaded converter will increase it's output voltage thus accepting more load. Like wise the heavy loaded converter will reduce voltage, automatically shedding load to parallel converters. In this way any number of converters may be connected in parallel for high power or redundant applications. In the prior art master/slave configuration, loss of the master unit is catastrophic. In the instant invention failure or removal of a unit causes the remaining unit/units to assume the additional load. The NSME sub-circuit PPT 1 A 2 provides efficient boost action at high power levels in a very small form factor. Inrush limiter sub-circuit ISIR ( FIG. 57 ) provides a ramp voltage to primary winding PPT 1 ( FIG. 19 ) of ouput stage ( FIG. 55A ) during start up and/or fault recovery. Additionally, sub-circuit ISIR functions as a second output interupt as taught in these specifications. The unique magnetic features allow full power operation at temperature ranges were common art converters cannot. Providing high power factor, transient protection, low inrush currents, excellent regulation, automatic recovery from fault conditions and quiet efficient operation at temperature extremes.
›ADDITIONAL EMBODIMENTS · 2 of 30
FIGS. 1 and 1A is a schematic diagram of a two stage power factor corrected AC to DC converter. The invention is comprised of line protection filter sub-circuit LL ( FIG. 20 ) and full-wave rectifier sub-circuit BR (FIG. 22 ). A power factor corrected regulated boost stage with sub-circuits PFA 2 (FIG. 23 ), snubber sub-circuit SN (FIG. 30 ), magnetic element sub-circuit PFT 1 (FIG. 18 ), sub-circuit CP (FIG. 26 ), buffer sub-circuit AMP (FIG. 29 ), over temperature sub-circuit OTP (FIG. 28 ), over voltage feedback sub-circuit IPFFB ( FIG. 40 ) and voltage feedback sub-circuit IFB (FIG. 40 B). Start up resistor R 2 , filter capacitor C 1 , PFC capacitor C 2 , flyback diode D 4 , switch transistor Q 1 , hold up capacitors C 17 and C 16 , and resistor R 17 . An efficient push-pull isolation stage with sub-circuits CPA (FIG. 27 ), PPG (FIG. 43 ), AMP 1 (FIG. 29 ), AMP 2 (FIG. 29 ), snubber sub-circuits SNB ( FIG. 32 ) and SNA (FIG. 31 ), resistor Rload, transistors Q 6 and Q 9 , magnetic element PPT 1 (FIG. 19 ), and OUTA (FIG. 25 ).
Table FIG. 1 Value/part Element number C1 0.01 uf C2 1.8 uf R2 100k ohms D4 8 A, 600 V Q1 IRFP 460 C17 100 uf C16 100 uf R17 375k ohms Q6 FS 14SM-18 A Q9 FS 14SM-18 A
In the two-stage converter the primary side voltage to the second push-pull output stage is modulated by the power factor corrected input (boost) stage. Each stage can comprise of individual and distributed NSME. Although the following description is in terms of particular converter topologies, i.e., flyback controlled primary and constant duty cycle push pull secondary, number of outputs, the style, and arrangement of the several topologies are offered by way of example, not limitation. In addition non-saturating magnetics BL 1 , PFT 1 , and PPT 1 may be implemented as distributed NSME. As an example PFT 1 is shown as a distributed magnetic PFT 1 A (FIG. 18 C). Distributed magnetics enable advantageous high voltage converter design variations that support form factor flexibility and multiple parallel secondary outputs from series coupled voltage divided primary windings across multiple NSME. The negative of the hold-up capacitor(s) [C 17 ∥C 16 ] is connected to boost output PF+. This allows the rectified line voltage to be excluded from the boost voltage in the hold-up capacitor(s). This, in turn, allows direct regulation of the push-pull stage from the boost stage. This eliminates the typical PWM control of the oversized thermally derated transformer and many sub-circuit components from the known art. AC line is connected to sub-circuit LL ( FIG. 20 ) between pins LL 1 and LL 2 . AC/earth ground is connected to node LL 0 . The filtered and voltage limited AC line appears on node/pin LL 5 of sub-circuit LL and connected to node BR 1 of bridge rectifier sub-circuit BR (FIG. 22 ). The neutral/AC return leg of the filtered and voltage limited AC appears on pin LL 6 of sub-circuit LL is connected to input pin BR 2 of BR. The line voltage is full-wave rectified and is converted to a positive haversine appearing on node BR+ of sub-circuit BR (FIG. 22 ). Start up resistor R 2 connects BR+ to sub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of control element sub-circuit PFA ( FIG. 23 ) and over temperature switch sub-circuit OTP ( FIG. 28 ) pin GAP. Resistor R 2 provides start up power to the control element until the rectifier/regulator CP is at full output. Node S 1 H from PFT 1 is connected to node PFVC of sub-circuit PFA. The zero crossings of the core are sensed when the voltage at S 1 H is at zero. The core zero crossings are used to reset the PFC and start a new cycle. The positive node of the DC side of bridge BR+ is connected through capacitor C 2 to BR−. C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor while reducing line harmonics and EMI. Primary of NSME sub-circuit PFT 1 ( FIG. 18 ) pins P 1 B and S 2 CT connects to pin SNL 1 of snubber sub-circuit SN (FIG. 30 ), to sub-circuit BR pin BR+ and connects to pin BR+ (FIG. 1 A). The return line for the rectified AC power BR− is connected to the following pins: BR− of sub-circuit BR, PFA pin BR−, sub-circuit AMP pin GA 0 , output switch Q 1 source, capacitor C 2 , sub-circuit CP pin CT 0 sub-circuit PFT 1 pin S 1 CT and CT 20 through EMI filter capacitor C 1 to earth ground node LL 0 . Pin BR+ from FIG. 1 is connected to FIG. 1A sub-circuits CPA pin SN pin SNL 1 , sub-circuit PFT 1 pin P 1 B, and sub-circuit PFT 1 pin S 2 CT. Pin BR+ continues to FIG. 1A connecting to sub-circuit CPA pin CT 20 , PPG ( FIG. 43 ) pin PPG 0 , sub-circuit AMP 1 pin GA 0 , sub-circuit AMP 2 pin GA 0 , sub-circuit IPFFB pin PF−, Capacitor [C 16 ∥C 17 ∥ resistor R 17 ], transistor Q 6 source, transistor Q 9 source, sub-circuit SNA pin SNA 2 and sub-circuit SNB pin SNB 2 . The drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit SN pin SNL 2 , and sub-circuit PFT 1 pin P 1 A and sub-circuit SN pin SNL 2 . Snubber network SN reduces the high voltage stress to Q 1 until flyback diode D 4 begins conduction. Line coupled, power factor corrected boost regulated output voltage of the AC to DC converter stage ( FIG. 1 ) appears on node PF+. Additional efficiency of approxamatly 0.2% is realized by connecting sub-circuit DSN ( FIG. 30A ) in parallel with D 4 . The regulated boost output PF+ connects to the following: sub-circuit SN pin SNOUT, sub-circuit DSN pin SNOUT and diode D 4 cathode. Node PF+ also connects on FIG. 1A to capacitors [C 16 ∥C 17 ∥R 17 ], sub-circuit IPFFB ( FIG. 40 ) pin PF+, sub-circuit PPT 1 ( FIG. 19 ) pin P 2 CT, snubber sub-circuit SNA ( FIG. 31 ) pin SNA 3 , and snubber SNB ( FIG. 32 ) pin SNB 3 . Magnetic element winding pin S 1 H of sub-circuit PFT 1 is connected to CP pin CT 1 A and pin PFVC of sub-circuit PFA. Magnetic element winding node S 1 L of sub-circuit PFT 1 is connected to CP pin CT 2 A. Magnetic element winding node S 2 H of sub-circuit PFT 1 is connected to pin 10 FIG. 1A then to CPA pin CT 1 B. Magnetic element winding node S 2 L of sub-circuit PFT 1 is connected to pin 12 FIG. 1A then to CPA pin CT 2 B. Sub-circuit PFA using the AC line phase, load voltage, and magnetic element feedback, generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFA ( FIG. 23 ) is connected to the input of buffer amplifier pin GA 1 of sub-circuit AMP (FIG. 29 ). Buffered high-speed gate drive output pin GA 2 of sub-circuit AMP is connected to gate of switch FET Q 1 . The buffering provided by AMP shortens switch Q 1 ON and OFF times greatly reducing switch losses (see FIGS. 13 & 14 ). Power to sub-circuit AMP is connected to pin GA+ from sub-circuit OTP pin TS+. Thermal switch THS 1 is connected to Q 1 . In the event the case of Q 1 reaches approximately 105 C THS 1 opens removing power to sub-circuit AMP, safely shutting down the first (input) stage. Normal operation resumes after the switch temperature drops 20-30 C closing THS 1 . Drain of output switch Q 1 is connected to primary winding pin P 1 A of non-saturating magnetic sub-circuit PFT 1 ( FIG. 18 ) and to pin SNL 2 of snubber sub-circuit SN ( FIG. 30 ) Reference voltage from PFC sub-circuit PFA pin PFA 2 is connected to feedback networks sub-circuit IPFFB pin FBC and to sub-circuit IFB pin FBC. Feedback current is summed at node PF 1 of sub-circuit PFA. Pin PF 1 is connected to feed back networks sub-circuit IPFFB pin FBE and to sub-circuit IFB pin FBE. Constant frequency/duty-cycle non-overlapping two-phase generator sub-circuit PPG ( FIG. 43 ) generates the drive for the push-pull output stage. Phase one output pin PH 1 is connected to sub-circuit AMP 1 pin GA 1 , second phase output pin PH 2 is connected to sub-circuit AMP 2 pin GA 1 . Output of amplifier buffer sub-circuit AMP 1 pin GAP 2 connects to gate of push-pull output switch Q 6 . Output of amplifier buffer sub-circuit AMP 2 pin GAP 2 connects to gate of push-pull output switch Q 9 . The buffering currents from AMP 1 and AMP 2 provide fast, low impedance critically damped switching to Q 6 and Q 9 greatly reducing ON-OFF transition time and switching losses. Regulated 18-volt power from sub-circuit CPA ( FIG. 1A ) pin CP 2 + is connected to amplifier buffer sub-circuit AMP 1 pin GA+, amplifier buffer sub-circuit AMP 2 pin GA+ and sub-circuit PPG pin PPG+. Drain of transistor Q 6 is connected to snubber network sub-circuit SNB pin SNB 1 and to non-saturating center tapped primary magnetic element sub-circuit PPT 1 pin P 2 H. Drain of transistor Q 9 is connected to snubber network sub-circuit SNA ( FIG. 31 ) pin SNAL and sub-circuit PPT 1 pin P 2 L. Source of transistor Q 6 is connected to snubber network sub-circuit SNB pin SNB 2 , transistor Q 9 source, sub-circuit SNA pin SNA 2 and to return node BR+. Isolated output of NSME sub-circuit PPT 1 pin SH connects to Pin C 7 B of rectifier sub-circuit OUTA (FIG. 25 A), pin SL connects to sub-circuit OUTA C 8 B. Center tap of PPT 1 pin SCT is the output return or negative node OUT− it connects to sub-circuit OUTA pin OUT− and sub-circuit IFB ( FIG. 40B ) pin OUT− and RLOAD. Converter positive output from sub-circuit OUTA pin OUT+ is connected to RLOAD and sub-circuit IFB pin OUT+. FIG. 1 elements LL, BR, PFA, AMP, Q 1 , IPFFB, IFB and PFT 1 (input stage) perform power factor corrected AC to DC conversion. The regulated high voltage output of this converter supplies the efficient fixed frequency/duty-cycle push-pull stage comprising PPG, AMP 1 , AMP 2 , Q 6 , Q 9 , PPT 1 and OUTA (FIG. 1 A). Magnetic element sub-circuit PPT 1 provides galvanic isolation and minimal voltage overshoot and ripple in the secondary thus minimizing filtering requirements of the rectifier sub-circuit OUTA. Five-volt reference output from sub-circuit PFA pin PFA 2 connects to node 15 then to FIG. 1A sub-circuit IPFFB pin FBC and to sub-circuit IFB pin FBC. Pulse width control input from sub-circuit PFA pin PF 1 connects to pin 14 then to FIG. 1A sub-circuit IPFFB pin FBE and to sub-circuit IFB pin FBE. Sub-circuit IFB provides high-speed feedback to the AC DC converter, the speed of the boost stage provides precise output voltage regulation and active ripple rejection. In the event of sudden line or load changes, sub-circuit IPFFB corrects the internal boost to maintain regulation at the isolated output. Remote load sensing and other feedback schemes known in the art may be implemented with sub-circuit IPFFB. This configuration provides power factor corrected input transient protection, rapid line-load response, excellent regulation, isolated output and quiet efficient operation at high temperatures.
›ADDITIONAL EMBODIMENTS · 3 of 30
FIG. 2 is a schematic diagram of an embodiment of a DC to AC converter. The invention DCAC 1 is an efficient push-pull converter. Comprised of sub-circuits PPG (FIG. 43 ), AMP 1 (FIG. 29 ), AMP 2 (FIG. 29 ), SNB (FIG. 32 ), SNA (FIG. 31 ), PPT 1 ( FIG. 19 ) switches Q 6 and Q 9 .
FIG. 2 Table Element Value/part number Q6 FS 14SM-18 A Q9 FS 14SM-18 A
Converter ACDC 1 accepts variable DC voltage and efficiently converts it to a variable AC voltage output at a fixed frequency. Variable frequency operation may be achieved by simple changes to PPG. In this embodiment fixed frequency operation is required. The magnetic element comprises non-saturating magnetics. Variable DC voltage is applied to pin DC+. The pin DC+ connects to the following, sub-circuit PPT 1 ( FIG. 19 ) pin P 2 CT, snubber sub-circuit SNA ( FIG. 31 ) pin SNA 3 , and snubber SNB ( FIG. 32 ) pin SNB 3 . Constant frequency non-overlapping two-phase generator sub-circuit PPG ( FIG. 43 ) generates the drive for the push-pull output switches. Phase one output pin PH 1 is connected to sub-circuit AMP 1 pin GA 1 , the second phase output pin PH 2 is connected to sub-circuit AMP 2 pin GA 1 . Output of amplifier buffer sub-circuit AMP 1 pin GAP 2 connects to gate of push-pull output switch Q 6 . Output of amplifier buffer sub-circuit AMP 2 pin GAP 2 connects to gate of push-pull output switch Q 9 . The buffering provided by AMP 1 and AMP 2 shortens switch Q 1 ON and OFF times greatly reducing switching losses (See FIGS. 13 and 14 ). External regulated 18-volt power from pin P 18 V connected to amplifier buffer sub-circuit AMP 1 pin GA+, amplifier buffer sub-circuit AMP 2 pin GA+ and sub-circuit PPG pin PPG+. Drain of transistor Q 6 is connected to snubber network sub-circuit SNB pin SNB 1 and to non-saturating center tapped primary magnetic element sub-circuit PPT 1 pin P 2 H. Drain of transistor Q 9 is connected to snubber network sub-circuit SNA ( FIG. 31 ) pin SNA 1 and sub-circuit PPT 1 pin P 2 L. Source of transistor Q 6 is connected to snubber network sub-circuit SNB pin SNB 2 , transistor Q 9 source, sub-circuit SNA pin SNA 2 , sub-circuit AMP 1 pin GA 0 , sub-circuit AMP 2 pin GA 0 , sub-circuit PPG pin PPG 0 , and to return pin DC−. AC output of NSME sub-circuit PPT 1 pin SH connects to Pin ACH, pin SL connects to pin ACL. Center tap of PPT 1 pin SCT is connected to pin AC 0 . Magnetic element sub-circuit PPT 1 provides galvanic isolation and minimal voltage overshoot in the secondary thus minimizing filtering requirements if a rectifier assembly is attached. Sub-circuit DCAC 1 may be used as a stand-alone converter or as a fast quiet efficient stage in a multi stage converter system. Sub-circuit DCAC 1 achieves isolated output, quiet operation, efficient conversion, and operation at high and low temperatures.
FIGS. 3 and 3A is a three-stage version of the present invention. The arrangement is comprised of an AC-DC or DC-DC boost converter stage, DC-DC forward converter stage, and a push-pull stage. This system reduces losses by combining low current buck regulation, buffered switching, rectified snubbering, and NSME in each stage. A power factor corrected boost stage is used to assure that any load connected to the converter looks like a resistive load to the AC line, eliminating undesirable harmonic and displacement currents in the AC power line. NSME having a lower permeability compared to the prior art are used to minimize magnetizing losses, improve coupling efficiency, minimize magnetic element heating, eliminate saturated core current spikes/gap leakage, reduce parts count, reduce thermal deterioration, and increase MTBF (mean time before failure). The invention also uses an emitter follower circuit with a high speed switching FET to slew the main FET gate rapidly. The use of non-saturating magnetics allows operation at higher voltages, which proportionally lowers current further reducing switch, magnetic element, and conductor losses due to I 2 R heating. High voltage FET switches have the added benefit of lower gate capacitance, which translates to faster switching. At turn on, the n-channel gate drive FET quickly charges the main FET gate. At turn off, a PNP Darlington transistor switch quickly discharges the main FET gate. The flyback effect in the PFC stage is managed by use of rectifying RC networks positioned across the output diode with an additional capacitor coupled diode across the switched magnetic element to decouple and further dampen the inductive flyback. The invention is comprised of a power factor corrected regulating boost stage with line protection filter sub-circuit LL ( FIG. 21 ) and full-wave rectifier sub-circuit BR ( FIG. 22 ) and capacitors C 1 and C 2 . Sub-circuits PFB (FIG. 24 ), resistor R 2 , rectifier CP (FIG. 26 ), magnetic element PFT 1 (FIG. 18 ), over temperature protection OTP ( FIG. 28 ) snubber SN ( FIG. 30 ) gate buffer AMP (FIG. 29 ), switch transistors Q 1 , flyback diode D 4 , holdup capacitors C 17 and C 16 , bleed resistor R 17 , and voltage feedback sub-circuit FBA (FIG. 40 A). An efficient second pre-regulating buck stage with sub-circuits PWFM (FIG. 33 ), current sense resistor R 26 , rectifier CPA (FIG. 27 ), magnetic element BL 1 (FIG. 18 B), over voltage protection OVP (FIG. 42 ), IPFFB ( FIG. 40 ) gate buffer AMP 3 (FIG. 29 ), switch transistor Q 2 , flyback diode D 70 , storage capacitor C 4 , and voltage feedback sub-circuit IFB (FIG. 40 B). An efficient third push-pull isolation stage with sub-circuits CPA (FIG. 27 ), two-phase generator PPG (FIG. 43 ), gate buffers AMP 1 ( FIG. 29 ) and AMP 2 (FIG. 29 ), switch transistors Q 6 , and Q 9 , snubbers SNA ( FIG. 31 ) and SNB (FIG. 32 ), magnetic element PPT 1 ( FIG. 19 ) and rectifier OUTA (FIG. 25 ).
AC line is connected to sub-circuit LLA ( FIG. 21 ) between pins LL 1 and LL 2 . AC/earth ground is connected to node LL 0 . The filtered and voltage limited AC line appears on node/pin LL 5 of sub-circuit LLA and connected to node BR 1 of bridge rectifier sub-circuit BR. The neutral/AC return leg of the filtered and voltage limited AC appears on pin LL 6 of sub-circuit LL is connected to input pin BR 2 of BR. The line voltage is full-wave rectified and is converted to a positive haversine appearing on node BR+ of sub-circuit BR. Start up resistor R 2 connects BR+ to sub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of control element sub-circuit PFB and over temperature switch sub-circuit OTP pin GAP. Resistor R 2 provides start up power to the control element until the regulator CP is at full output. Node S 1 H from PFT 1 is connected to pin 31 ( FIG. 3 ) then to pin CT 1 A of sub-circuit CP and pin PFVC of sub-circuit PFB. The zero crossing of the core bias are sensed when the voltage at S 1 H is at zero relative to BR−. The core zero crossings are used to reset the PFC and start a new cycle. The positive node of the DC side of bridge BR+ is connected through capacitor C 2 to BR−. Capacitor C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor. Sub-circuit BR pin BR+ connects to pin SNL 1 of snubber sub-circuit SN, sub-circuit PFB pin BR+ and pin BR+ ( FIG. 3A ) then to primary of NSME sub-circuit PFT 1 pin P 1 B and to sub-circuit OVP pin BR+. The return line for the rectified AC power is connected to the following pins; BR− of sub-circuit BR, sub-circuit PFT 1 pin SLCT, PFC sub-circuit PFB pin BR−, sub-circuit FBA pin BR−, capacitor C 2 , sub-circuit CP pin CT 0 , sub-circuit IPFFB pin FBE, and through EMI filter capacitor C 1 to earth ground node LL 0 . Node BR− continues to FIG. 3A connecting to R 26 , capacitors [C 16 ∥C 17 ∥R 17 ], sub-circuit OVP pin BR−, sub-circuit PWFM pin PWFMO, sub-circuit AMP 3 pin GA 0 , switch Q 2 source. Floating ground node PF− is connected to magnetic element sub-circuit PFT 1 pin S 2 CT, rectifier sub-circuit CPA pin CT 20 , generator sub-circuit PPG ( FIG. 43 ) pin PPG 0 , sub-circuit AMP 1 pin GA 0 , sub-circuit AMP 2 pin GA 0 , capacitor C 4 , magnetic element BL 1 pin, transistor Q 6 source, transistor Q 9 source, sub-circuit SNA pin SNA 2 sub-circuit SNB pin SNB 2 , pin PF-( FIG. 3 ) then to sub-circuit IPFFB pin PF−. Drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit SN pin SNL 2 , then to pin 34 of FIG. 3A then to sub-circuit PFT 1 pin P 1 A. Snubber SN reduces the high voltage stress to Q 1 until flyback diode D 4 begins conduction. Additional rectification efficiency and protection is achieved by adding sub-circuit DSN ( FIG. 30A ) across flyback diode D 4 . Feedback corrected boost output voltage of the power factor corrected AC to DC converter stage appears across nodes PF+ and PF−. The regulated 385-volt boost output node PF+ connects to the following; sub-circuit SN pin SNOUT, diode D 4 cathode, sub-circuit IPFFB ( FIG. 40 ) pin PF+, sub-circuit FBA pin PF+, then to pin PF+ of FIG. 3A , capacitors [C 16 ∥C 17 ∥R 17 ], magnetic element sub-circuit PTT 1 ( FIG. 19 ) pin P 2 CT, snubber sub-circuit SNA ( FIG. 31 ) pin SNA 3 , and snubber SNB ( FIG. 32 ) pin SNB 3 , sub-circuit OVP pin PF+, capacitor C 4 and diode D 70 cathode. Magnetic element winding node S 1 H of sub-circuit PFT 1 is connected to pin 31 ( FIG. 3 ) then to sub-circuit CP pin CT 1 A and pin PFVC of sub-circuit PFB. Magnetic element winding node S 1 L of sub-circuit PFT 1 is connected to pin 33 FIG. 3 then to sub-circuit CP pin CT 2 A. Magnetic element winding node S 2 H of sub-circuit PFT 1 is connected to CPA pin CTLB. Magnetic element winding node S 2 L of sub-circuit PFT 1 is connected to CP pin CT 2 B. Sub-circuit PFB using feedback from the phase of the AC line, Q 1 switch current, magnetic bias first stage and output voltage feedback generates a command pulse on pin PFCLK. Pin PFCLK of sub-circuit PFB ( FIG. 24 ) is connected to the input of buffer AMP amplifier pin GA 1 of sub-circuit AMP 1 . Buffered high-speed low impedance gate drive output pin GA 2 of sub-circuit AMP is connected to gate of switch FET Q 1 . The buffering provided by AMP shortens switch Q 1 “ON” and “OFF” times greatly reducing switch losses (See FIGS. 13 and 14 ). The source of Q 1 is connected to sub-circuit AMP pin GA 0 , pin 35 of FIG. 3A then to current sense resistor R 26 connected to return node BR−. The voltage developed across R 26 is fed back to PFB pin PFSC. This signal is used to protect the switch by reducing the pulse width in response to a low line or high load induced over current fault. This feedback is non-isolated; network values are selected for the first stage to develop a 385-Volt output at PF+. Sub-circuit feedback network FBA ( FIG. 40A ) pin PF 1 is connected to sub-circuit PFB pin PF 1 . Controller PFB modulates PFCLK signal to maintain a substantially constant 385-voltage at PF+ independent of line and load conditions. In the event of a component failure in sub-circuit FBA the PBF may command the converter to very high voltages. Sub-circuit OVP monitors the first stage boost in the event it exceeds 405-volts OVP will clamp the output of sub-circuit BR causing fuse F 1 in sub-circuit LLA to open. An alternate over voltage network OVP 1 ( FIG. 42A ) may replace OVP clamping the 18-volt control power stopping the boost action of the converter without opening the fuse. The haversine on BR+ is used with an internal multiplier by PFB to generate variable width control pulses on pin PFCLK. The high frequency modulation of switch Q 1 makes the load/converter appear resistive to the AC line. Over temperature protection sub-circuit OTP pin TS+ is connected to sub-circuit AMP pin GA+. Thermal switch THS 1 is connected to Q 1 . In the event Q 1 reaches approximately 105 C THS 1 opens removing power to sub-circuit AMP, safely shutting down the first stage. Normal operation resumes after the temperature decreases 20-30 C closing THS 1 . The second stage is configured as a buck stage. It accepts the 385-Volt output of the first stage. By employing a second floating reference node PF− energy storage element capacitor C 4 the voltage to the final push-pull stage may be regulated with minimal loss. Power from sub-circuit CP pin CP 18 V+ is connected to pin 30 of FIG. 3A then to sub-circuit PWFM ( FIG. 33 ) pin PWM+ and AMP 3 pin GA+. Feedback current from sub-circuit IPFFB pin FBC is connected to pin 36 FIG. 3A then to sub-circuit IFB pin FBC and sub-circuit PWFM pin PF 1 . Sub-circuit IPFFB only shunts current from this node if the output of the second stage is greater than 200-volts. When the converter reaches its designed output voltage, IFB shunts current from PWFM pin PF 1 signaling PWFM to reduce the pulse width on pin PWMCLK. Sub-circuit AMP 3 input pin is connected to sub-circuit PWFM pin PWMCLK. Output of AMP 3 buffer pin GA 2 is connected to gate of switch Q 2 . Drain of Q 2 is connected to anode of D 70 and non-saturating magnetic sub-circuit BL 1 pin P 2 B (FIG. 18 B). Turning on switch Q 2 charges C 4 also storing energy in magnetic element BL 1 . Releasing switch Q 2 allows energy stored in magnetic element BL 1 to charge C 4 through flyback diode D 70 . Larger pulse widths charge C 4 to larger voltages thus efficiently blocking part of the first stage voltage to the final push-pull stage. This action provides regulated voltage to the final converter stage. The third and final push-pull (transformer) converter stage provides the galvanic isolation, filtering and typically converts the internal high voltage bus to a lower regulated output voltage. The efficient push-pull stage produces alternating magnetizing currents in the NSME for maximum load over core mass. Constant frequency non-overlapping two-phase generator sub-circuit PPG ( FIG. 43 ) generates the drive for the push-pull output stage. Phase one output pin PH 1 is connected to sub-circuit AMP 1 pin GA 1 , output pin PH 2 is connected to sub-circuit AMP 2 pin GA 1 . Output of amplifier buffer sub-circuit AMP 1 pin GAP 2 connects to gate of push-pull output switch Q 6 . Output of amplifier buffer sub-circuit AMP 2 pin GAP 2 connects to gate of push-pull output switch Q 9 . The buffering provided by AMP 1 and AMP 2 shortens switch Q 1 ON and OFF times greatly reducing switching losses. (See FIGS. 13 and 14 ) Regulated 18-volt power from sub-circuit CPA pin CP 18 + is connected to amplifier buffer sub-circuit AMP 1 pin GA+, amplifier buffer sub-circuit AMP 2 pin GA+ and sub-circuit PPG pin PPG+. Drain of transistor Q 6 is connected to snubber network sub-circuit SNB pin SNB 1 and to non-saturating center tapped primary magnetic element sub-circuit PPT 1 pin P 2 H. Drain of transistor Q 9 is connected to snubber network sub-circuit SNA ( FIG. 31 ) pin SNA 1 and sub-circuit PPT 1 pin P 2 L. Output of NSME sub-circuit PPT 1 pin SH connects to pin C 7 B of rectifier sub-circuit OUTA (FIG. 25 ), pin SL connects to C 8 B. Center tap of PPT 1 pin SCT is the output return or negative node OUT− it connects to sub-circuit pin OUT− and sub-circuit IFB pin OUT− and RLOAD. Supply positive output from sub-circuit OUTA pin OUT+ is connected to RLOAD and sub-circuit IFB pin OUT+. Elements LLA, BR, PFA, AMP, Q 1 , IPFFB, IFB and PFT 1 provide power factor corrected AC to DC conversion and DC output regulation. The regulated high voltage output of this converter is used to power the efficient fixed frequency push-pull stages PPG, AMP 1 , AMP 2 , Q 6 , Q 9 , PPT 1 and OUTA. Magnetic element sub-circuit PPT 1 provides galvanic isolation and minimal voltage overshoot in the secondary thus minimizing filtering requirements of the rectifier sub-circuit OUTA. Sub-circuit IFB provides high-speed feedback to the AC DC converter, the speed of the boost stage provides precise output voltage regulation and active ripple rejection. In the event of a sudden line or load changes sub-circuit IPFFB compensates the internal boost. This system reduces losses by focusing output control in the middle (low current) stage of the converter and by using non-saturating magnetics, buffered switching, and rectifying snubbers throughout each stage. The combined improvements translate to higher system efficiencies, higher power densities, lower operating temperatures, and, improved thermal tolerance thereby reducing or eliminating the need for forced air-cooling per unit output. The non-saturating magnetic properties are relatively insensitive to temperature (see FIG. 17 ), thus allowing the converter to operate over a greater temperature range. In practice, the operating temperature for the Kool Mu NSME is limited to 200 C by wire/core insulation; the non-saturating magnetic material remains operable to near its Curie temperature of 500 C. This configuration provides power factor corrected input transient protection, rapid line-load and ripple compensation, excellent output regulation, output isolation and quiet efficient operation at high temperatures.
›ADDITIONAL EMBODIMENTS · 4 of 30
FIG. 4 is a schematic diagram of a power factor corrected single stage AC to DC converter sub-circuit ACDCPF. The invention is comprised of line protection filter sub-circuit LL ( FIG. 20 ) and full-wave rectifier sub-circuit BR (FIG. 22 ). A power factor corrected regulated boost stage with sub-circuits PFB (FIG. 24 ), snubber sub-circuit SN (FIG. 30 ), magnetic element sub-circuit PFT 1 A (FIG. 18 A), sub-circuit CP (FIG. 26 ), buffer sub-circuit AMP (FIG. 29 ), over temperature sub-circuit OTP (FIG. 28 ), and voltage feedback sub-circuit FBA (FIG. 40 A). Start up resistor R 2 , filter capacitor C 1 , PFC capacitor C 2 , flyback diode D 4 , switch transistor Q 1 , hold up capacitors C 17 and C 16 , and resistor R 17 .
AC line is connected to sub-circuit LL ( FIG. 20 ) between pins LL 1 and LL 2 . AC/earth ground is connected to node LL 0 . The filtered and voltage limited AC line appears on node/pin LL 5 of sub-circuit LLA and connected to node BR 1 of bridge rectifier sub-circuit BR (FIG. 22 ). The neutral/AC return leg of the filtered and voltage limited AC appears on pin LL 6 of sub-circuit LL is connected to input pin BR 2 of BR. The line voltage is full-wave rectified and is converted to a positive haversine appearing on node BR+ of sub-circuit BR (FIG. 22 ). Start up resistor R 2 connects BR+ to sub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of power factor controller sub-circuit PFA ( FIG. 24 ) and over temperature switch sub-circuit OTP ( FIG. 28 ) pin GAP. Resistor R 2 provides start up power to the control element until the rectifier and regulator CP is at full output. Node S 1 H from PFT 1 A is connected to node PFVC sub-circuit PFB. The zero crossing of the core bias are sensed when the voltage at S 1 H is at zero. The core zero crossings are used to reset the PFC and start a new cycle. The positive node of the DC side of bridge BR+ is connected through capacitor C 2 to BR−. C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor. Primary of NSME sub-circuit PFT 1 A ( FIG. 18A ) pin PIB connects to pin SNL 1 of snubber sub-circuit SN (FIG. 30 ), sub-circuit PFB pin BR+ and connects to node BR+. The return line for the rectified AC power BR− is connected to the following pins; BR− of sub-circuit BR, sub-circuit PFB pin BR−, sub-circuit AMP pin GA 0 , sense resistor R 26 , capacitor [C 16 ∥C 17 ∥resistor R 17 ], capacitor C 2 , sub-circuit CP pin CT 0 , sub-circuit PFT 1 A pin S 1 CT and through EMI filter capacitor C 1 to earth ground node LL 0 . Drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit PFT 1 A pin P 1 A and snubber sub-circuit SN pin SNL 2 . Additional rectification efficiency and protection is achieved by adding sub-circuit DSN ( FIG. 30A ) in parallel flyback diode D 4 . Sub-circuit provides reduces the high voltage stress to Q 1 until flyback diode D 4 begins conduction. Line coupled, power factor corrected boost regulated output voltage of the AC to DC converter stage ( FIG. 1 ) appears on node PF+. The regulated boost output PF+ connects to the following; sub-circuit SN pin SNOUT, diode D 4 cathode, capacitor [C 16 ∥C 17 ∥R 17 ], and snubber DSN ( FIG. 30A ) pin SNOUT. Magnetic element winding node S 1 H of sub-circuit PFT 1 A is connected to CP pin CT 1 A and pin PFVC of sub-circuit PFB. Magnetic element winding node S 1 L of sub-circuit PFT 1 A is connected to CP pin CT 2 A. Sub-circuit PFB using the phase of the AC line, and load voltage generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFB ( FIG. 24 ) is connected to the input of buffer amplifier pin GA 1 of sub-circuit AMP 1 (FIG. 29 ). Buffered high-speed gate drive output pin GA 2 of sub-circuit AMP is connected to gate of switch FET Q 1 . The buffering provided by AMP shortens switch Q 1 ON and OFF times greatly reducing switch losses. The source of Q 1 is connected to current sense resistor R 26 , pin PFSC of sub-circuit PFB, connected then to return node BR−. The voltage developed across R 26 is feedback to PFB pin PFSC. This signal is used to protect the switch in the event of an over current fault. Thermal switch THS 1 is connected to Q 1 . In the event Q 1 reaches approximately 105 C THS 1 opens removing power to sub-circuit AMP, safely shutting down the first stage. Normal operation resumes after the switch temperature drops 20-30 C closing THS 1 . Sub-circuit feedback network FBA ( FIG. 40A ) pin PF 1 is connected to sub-circuit PFB pin PF 1 . Converter output at node PF+ (the junction of [C 17 ∥C 16 ] and D 4 ) is connected to sub-circuit FBA pin PF+. The return line of sub-circuit FBA pin BR− is connected to pin BR− of sub-circuit PFB. This feed back is non-isolated; network values are selected for a substantially constant 385-Volt output at PF+ relative to BR−. The high-voltage haversine from the rectifier section BR pin BR+ is connected to sub-circuit PFB pin BR+. The haversine is used with an internal multiplier by PFB to make the converter ACDCPF appear resistive to the AC line. Sub-circuits LLA, BR, PFB, AMP, Q 1 , OTP, FBA, IFB and PFT 1 A perform power factor corrected AC to DC conversion. The regulated high voltage output of this converter may be used use to power one or more external converters connected to the PF+ and BR− nodes. The NSME sub-circuit PPT 1 A provides efficient boost action at high power levels in a very small form factor. Sub-circuit FBA provides high-speed feedback to the converter the speed of the boost stage provides precise output voltage regulation and active ripple rejection. This configuration provides power factor corrected input transient protection, rapid line-load response, excellent regulation, and quiet efficient operation at high temperatures.
FIG. 4A is a schematic diagram of a power factor corrected converter with auto load leveling sub-circuit ACDCPF 1 . The invention is comprised of line filter sub-circuit LF (FIG. 20 A), fast start sub-circuit FS 1 (FIG. 45 ), transient diodes D 460 , D 461 , and D 462 ( FIG. 46 ) and inrush limiter sub-circuit SS 1 (FIG. 44 ). A power factor corrected regulated boost stage with sub-circuits PFB (FIG. 24 ), snubber sub-circuit SNBB (FIG. 30 B), magnetic element sub-circuit PFT 1 A (FIG. 18 A), sub-circuit CP 1 (FIG. 26 A), buffer sub-circuit AMP (FIG. 29 ), over temperature sub-circuit OTP (FIG. 28 ), over voltage sub-circuit FB 2 (FIG. 41 A), and voltage feedback sub-circuit FBD (FIG. 40 D). Auto load-leveling resistor R 345 , filter capacitor C 1 , PFC capacitor C 2 , flyback diode D 4 , switch transistor Q 1 , hold up capacitors C 442 and C 417 .
›ADDITIONAL EMBODIMENTS · 5 of 30
AC line is connected to sub-circuit LF ( FIG. 20A ) between nodes LL 1 and LL 2 . AC/earth ground is connected to node LL 0 . The filtered and rectified AC line appears on pin BR+ of sub-circuit LF connects to anode of transient diodes D 460 - 462 . Cathode of diodes D 460 - 462 connects to node PF+ and main storage capacitor C 442 . The line voltage is full-wave rectified converted to a positive haversine appearing on node B+ of sub-circuit LF (FIG. 20 A). Node B+ of filter sub-circuit LF is connected to input pin BR+ of PFB (FIG. 24 ), positive of C 2 , pin PB 1 of PFT 1 A, pin B+ of SS 1 . Capacitor C 2 is selected for various line and load conditions to de-couple switching current from the line improving power factor. Fast start sub-circuit FS 1 node TP 17 connects to sub-circuit CP 1 pin TP 17 . Node VCC of CP 1 connects to pin PFA+ of power factor controller sub-circuit PFB (FIG. 24 ), auto load leveling resistor R 345 connects to pin PF 1 of PFB and PF 1 of FBD. VCC of FS 1 connects to over temperature switch sub-circuit OTP ( FIG. 28 ) pin GAP. Fast start FS 1 provides start up power until the converter is at full power. It also provides control power in the event of an extended loss of boost. Node S 1 H from PFT 1 A is connected to node PFVC sub-circuit PFB. The zero crossing of the core bias are sensed when the voltage at SH 1 is at zero. The core zero crossings are used to reset U 1 B and start a new cycle. Primary of NSME sub-circuit PFT 1 A ( FIG. 18A ) pin P 1 B connects to pin SNL 2 of snubber sub-circuit SNBB (FIG. 30 B), sub-circuit PFB pin BR+ and connects to node B+. Return line for the rectified AC power BR− is connected to the following pins; BR− of sub-circuit LF, sub-circuit PFB pin BR−, sub-circuit AMP pin GA 0 , sub-circuit SS 1 pin BR−, sense resistor R 26 , sub-circuit SS 1 pin BR−, capacitors C 417 and C 2 , sub-circuit CP 1 pin CT 0 , sub-circuit FB 2 pin BR−, sub-circuit FBD pin BR−, sub-circuit FS 1 pin BR−, sub-circuit PFT 1 A pin SLCT and through EMI filter capacitor C 1 to earth ground node LL 0 . Drain of output switch Q 1 is connected to diode D 4 anode, sub-circuit PFTLA pin P 1 A and snubber sub-circuit SNBB pin SNL 2 . Switch protection is achieved by adding sub-circuit SNBB ( FIG. 30B ) in parallel flyback diode D 4 . Sub-circuit SNBB provides reduces the high voltage stresses to Q 1 until flyback diode D 4 begins conduction. Regulated output voltage of the converter appears on node PF+. The regulated boost output PF+ connects to the following; sub-circuit SNBB pin SNOUT, diode D 4 cathode, capacitor C 417 , sub-circuit FS 1 pin PF+, sub-circuit SS 1 pin PF+, and diode D 460 - 462 cathodes. Magnetic element winding node S 1 H of sub-circuit PFT 1 A is connected to CP 1 pin CT 1 A and pin PFVC of sub-circuit PFB. Magnetic element winding node S 1 L of sub-circuit PFT 1 A is connected to CPI pin CT 2 A. Sub-circuit PFB using the phase of the AC line, and load voltage generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFB ( FIG. 24 ) is connected to the input of buffer amplifier pin GA 1 of sub-circuit AMP 1 (FIG. 29 ). Buffered high-speed gate drive output pin GA 2 of sub-circuit AMP is connected to gate of main switch Q 1 . The buffering provided by AMP shortens switch Q 1 “ON” and “OFF” times greatly reducing switch losses. The source of Q 1 is connected to current sense resistor R 26 , pin PFSC of sub-circuit PFB, connected then to return node BR−. The voltage developed across R 26 is feedback to PFB pin PFSC. This signal is used to protect the switch in the event of an over current fault. Thermal switch THS 1 is thermally connected to Q 1 . In the event Q 1 reaches approximately 105 C THS 1 opens removing power to sub-circuit AMP, safely shutting down boost operation. Normal operation resumes after the switch temperature drops 20-30 C closing THS 1 . Sub-circuit feedback network FBD ( FIG. 40D ) pin PF 1 is connected to sub-circuit PFB pin PF 1 . Sub-circuit feedback network FB 2 ( FIG. 41A ) pin PF 2 is connected to sub-circuit PFB pin PF 2 . This feed back is non-isolated; network values are selected for a substantially constant 385-Volt output at PF+ relative to BR−. The high-voltage haversine from the rectifier section pin B+ is connected to sub-circuit PFB pin BR+. The haversine is used with an internal multiplier by PFB to make the converter ACDCPF 1 appear resistive to the AC line. The regulated high voltage output of this converter may be used use with one or more external converters connected in parallel. A unique feature of the converter ACDCPF 1 is the automatic load-sharing feature. Where the signal VCC varies as a function of load as shown in FIG. 26 B. Load leveling R 345 resistor connected between nodes VCC and PF 1 regulates the output voltage lower as the load/boost increases. This unique action allows units to be operated in parallel with out the typical master slave connections. In this way the lightly loaded converter will increase it's output voltage thus accepting more load. Like wise the heavy loaded converter will reduce voltage, automatically shedding load to parallel converters. In this way any number of converters may be connected in parallel for high power or redundant applications. In the prior art master/slave configuration, loss of the master unit is catastrophic. In the instant invention failure or removal of a unit causes the remaining unit/units to assume the additional load. The NSME sub-circuit PPT 1 A 1 provides efficient boost action at high power levels in a very small form factor. Inrush limiter sub-circuit SS 1 allows “hot swapping” with minimal system disturbance. The unique magnetic features allow full power operation at temperature ranges were common art converters can not. Providing high power factor, transient protection, low inrush currents, excellent regulation, automatic recovery from fault conditions and quiet efficient operation at temperature extremes.
FIG. 5 is a graph comparing typical currents in saturating and non-saturating magnetic elements. As the inductance does not radically change at high temperatures and currents in the NSME, the large current spikes due to the rapid reduction of inductance common in saturating magnetics is not seen. As a result, destructive current levels, excessive gap leakage, magnetizing losses, and magnetic element heating are avoided in NSME.
›ADDITIONAL EMBODIMENTS · 6 of 30
FIG. 6 is a schematic for non-isolated low side switch buck converter sub-circuit NILBK. Sub-circuit NILBK consists of resistor R 20 , diode D 6 , capacitor C 6 , FET transistor Q 111 , sub-circuit CP (FIG. 26 ), sub-circuit PFT 1 A (FIG. 18 A), sub-circuit IFB (FIG. 40 B), sub-circuit AMP ( FIG. 29 ) and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+ through resistor R 20 connects to sub-circuit CP pin CP+, sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Resistor R 20 provides startup power to the converter before regulator sub-circuit CP reaches it full 18-volt output. VBAT negative is connected to pin DCIN− connects to sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , Q 111 source, sub-circuit IFB pin FBE, sub-circuit CP pin CT 0 , and sub-circuit PFT 1 pin SLCT. Magnetic element winding node S 1 L of sub-circuit PFT 1 A is connected to CP pin CT 1 A. Magnetic element winding node S 1 H of sub-circuit PFT 1 A is connected to CP pin CT 2 A. The regulated 18 volts from sub-circuit CP+ is connected to R 20 , sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit PWFM is designed for variable pulse width operation. PWFM is configured for maximum pulse width 90-95% with no feedback current from sub-circuit IFB pin FBC. Increasing the feedback current reduces the pulse-width and output voltage from converter NILBK. Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP. The output of sub-circuit AMP pin GA 2 is connected to the gate of Q 111 . Input node DCIN+ connects to the cathode of flyback diode D 6 , sub-circuit IFB pin OUT+, resistor RLOAD, capacitor C 6 and pin B+. The drain of Q 111 is connected to sub-circuit PFT 1 pin P 1 B and the anode of D 6 . Pin P 1 A of sub-circuit PFT 1 A is connected to capacitor C 6 , RLOAD, sub-circuit IFB pin OUT− and to node B−. With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 111 . Switch Q 111 conducts charging capacitor C 10 through NSME PFT 1 A from source VBAT and storing energy in PFT 1 A. Feedback output pin FBC from sub-circuit IFB is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . Sub-circuit IFB removes current from PW 1 commanding PWFM to reduce the pulse-width or on time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PWFM switches output pin CLK low turning “off” Q 111 stopping the current into PFT 1 A. The energy not transferred into regulator sub-circuit CP load is released from NSME PFT 1 A into the now forward biased diode D 6 charging capacitor C 6 . By modulating the “on” time of switch Q 111 the converter buck voltage is regulated. Regulated voltage is developed across Nodes B− and B+. Sub-circuit IFB provides the isolated feedback voltage to the sub-circuit PWFM. When sub-circuit IFB senses the converter output (nodes B+ and B−) is at the designed voltage, current from REF is removed from PW 1 . Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 111 is removed stopping all buck activity capacitor C 6 discharges through RLOAD. Input current from VBAT is sinusoidal making the converter very quiet. In addition the switch Q 111 is not exposed to large flyback voltage. Placing less stress on the switches thereby increasing the MTBF. Sub-circuit NILBK takes advantage of the desirable properties of the NSME in this converter topology. Adjusting the NSME 100 ( FIG. 18A ) primary inductance and component values in sub-circuit IFB determines the output buck voltage.
FIG. 7 is a schematic of the tank coupled single stage converter sub-circuit TCSSC. Sub-circuit TCSSC consists of resistor R 20 and RLOAD, capacitor C 10 , transistors Q 21 and Q 11 , sub-circuit CP (FIG. 26 ), sub-circuit PFT 1 (FIG. 18 ), sub-circuit OUTA (FIG. 25 ), sub-circuit AMP (FIG. 29 ), sub-circuit IFB ( FIG. 40B ) and sub-circuit PWFM (FIG. 33 ).
TCSSC can be configured to operate as an AC-DC converter, a DC-DC converter, a DC-AC converter, and an AC-AC converter. External power source VBAT connects to pins DCIN+ and DCIN−. Source power may also be derived from rectified AC line voltage such as FIG. 20 or FIG. 21 to form a single stage power factor corrected AC to DC converter with isolated output. From DCIN+ resistor R 20 connects to sub-circuit CP pin CP+, sub-circuit AMP pin GA+, U 12 LED anode and to sub-circuit PWFM pin PWFM+. Resistor R 20 provides startup power to the converter until the control supply regulator sub-circuit CP reaches the desired 18-volt output. VBAT negative is the ground return node connects to sub-circuit PWFM pin PWFM 0 , Q 11 source, sub-circuit AMP pin GA 0 , sub-circuit CP pin CT 0 , pin DCIN− and sub-circuit PFT 1 pin S 1 CT. Magnetic element winding node S 1 H of sub-circuit PFT 1 is connected to CP pin CT 1 A. Magnetic element winding node S 1 L of sub-circuit PFT 1 is connected to CP pin CT 2 A. Sub-circuit PWFM is designed as a constant 50% duty-cycle variable frequency generator. Sub-circuit PWFM Clock output pin CLK is connected to input of buffer sub-circuit AMP pin GA 1 . The output of buffer sub-circuit AMP pin GA 2 is connected to the gate of Q 11 and R 21 . Resistor R 21 is connected to the cathode of U 12 LED. The emitter of Q 21 and drain of Q 11 is connected to sub-circuit PFT 1 pin P 1 A. Pin P 1 B of sub-circuit PFT 1 is connected through tank capacitor C 10 to node DCIN+, Q 21 collector and through resistor R 61 to U 12 phototransistor collector. The emitter of U 12 phototransistor is connected to the base of Q 21 . With PWFM pin CLK high transistor Q 11 conducts charging capacitor C 10 through NSME PFT 1 from VBAT storing energy in PFT 1 . Sub-circuit PWFM switches CLK low, Q 11 turns “off”. With CLK low LED of U 12 is turned “on” injecting base current into Q 21 . With transistor Q 21 “on” the tank circuit is completed, allowing capacitor C 10 to discharge into NSME PFT 1 winding 100 (FIG. 18 ). Now the energy not transferred into the load is released from NSME PFT 1 into the now forward biased NPN switch Q 21 back into capacitor C 10 . Thus any energy not used by the secondary load remains in the tank coupled primary circuit (winding 100 ). When the switching occurs at the resonant frequency, high voltages oscillate between C 10 and winding 100 creating high flux density AC excursions in PFT 1 . C 10 and PFT 1 exchange variable AC currents whose magnitude is controlled by frequency modulation scheme IFB and PWFM. The large primary voltage generates large, high frequency biases in the NSME PFT 1 thereby producing high flux density AC excursions to be harvested by secondary windings 102 and 103 ( FIG. 18 ) to support a load or rectifier sub-circuit OUTA. Magnetic element winding node S 2 H of sub-circuit PFT 1 is connected to OUTA pin C 7 B. Magnetic element winding node S 2 L of sub-circuit PFT 1 is connected to OUTA pin C 8 B. Magnetic element winding node S 2 CT of sub-circuit PFT 1 is connected to OUTA pin OUT−. Node OUT− is connected to RLOAD, pin B− and to sub-circuit IFB pin OUT−. Rectified power is delivered to pin OUT+ of OUTA and is connected to RLOAD, pin B+ and to sub-circuit IFB pin OUT+. Sub-circuit IFB provides the isolated feedback signal to the sub-circuit PWFM. Frequency control pin FM 1 of sub-circuit PWFM is connected to sub-circuit IFB pin FBE. Internal reference pin REF of sub-circuit PWFM is connected to sub-circuit IFB pin FBC. PWFM is designed to operate at the resonate frequency of the tank (2*pi*(square root (C 10 *inductance of 100 (FIG. 18 )). When sub-circuit IFB senses the converter output is at the target voltage, current from PWFM pin REF is injected into FM 1 . Injecting current into FM 1 commands the PWFM to a lower clock frequency pin CLK. Driving the tank out of resonance reduces the amount of energy added to the tank thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM off or 0 Hz, i.e.: at no load, all primary activity stops. The input current from VBAT may be steady state or variable DC. When TCSSC is operated from rectified AC (sub-circuit LL FIG. 20 ), high input (line) power factor and input transient protection is achieved. The primary and secondary currents of PFT 1 are sinusoidal and free of edge transitions making the converter very quiet. In addition the switches Q 11 and Q 21 are never exposed to the large circulating voltage induced in the tank (See FIG. 35 ). This allows the use of lower voltage switches in the design thereby reducing losses and increasing the MTBF. Sub-circuit TCSSC takes advantage of the desirable properties of the NSME in this converter topology. TCSSC is well suited for implementation with distributed NSME PFT 1 D (FIG. 18 C). This combination exemplifies how distributed magnetics enable advantageous high voltage converter design variations that support form factor flexibility and multiple parallel secondary outputs from series coupled voltage divided primary windings across multiple NSME. This magnetic strategy is useful in addressing wire/core insulation, form factor and packaging limitations, circuit complexity and manufacturability. These converter strategies are very useful for obtaining isolated high current density output from a high voltage low current series coupled primary. Adjusting the secondary turn's ratio allows TCSSC to generate very large AC or DC output voltages as well as low-voltage high current outputs.
›ADDITIONAL EMBODIMENTS · 7 of 30
FIG. 8 is a schematic for a tank coupled single stage converter sub-circuit TCTP. Sub-circuit TCTP consists of resistor R 20 and RLOAD, capacitor C 10 , Darlington transistors Q 10 and Q 20 , sub-circuit CP (FIG. 26 ), sub-circuit PFT 1 (FIG. 18 ), sub-circuit OUTB (FIG. 25 A), sub-circuit IFB ( FIG. 40B ) and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+ connects to Q 10 collector then through resistor R 20 connects to sub-circuit CP pin CP+ and to sub-circuit PWFM pin PWFM+. Resistor R 20 provides startup power to the converter before regulator sub-circuit CP reaches it full 18-volt output. VBAT negative is connected to pin DCIN− ground/return node GND. Node GND connects to sub-circuit PWFM 0 pin PWFM 0 , Q 20 collector, C 10 , sub-circuit CP pin CT 0 and sub-circuit PFT 1 pin S 1 CT. Magnetic element winding node S 1 H of sub-circuit PFT 1 is connected to CP CT 1 A. Magnetic element winding node S 1 L of sub-circuit PFT 1 is connected to CP CT 2 A. Magnetic element winding node S 1 CT of sub-circuit PFT 1 is connected to CP pin CT 0 . Magnetic element winding node S 2 CT of sub-circuit PFT 1 is connected to OUTB pin OUT−. Regulated 18-volts from sub-circuit CP+ is connected to R 20 and to sub-circuit PWFM pin PWFM+. Sub-circuit PWFM is designed for a constant 50% duty cycle variable frequency generator. Sub-circuit PWFM clock output pin CLK is connected to the base of Q 10 and Q 20 . The emitters of Q 10 and Q 20 are connected to sub-circuit PFT 1 pin P 1 B. This forms an emitter follower configuration. Pin P 1 A of sub-circuit PFT 1 is connected through tank capacitor C 10 to node GND. With PWFM CLK pin high forward biased transistor Q 10 supplies current to the tank from BAT 1 charging capacitor C 10 through NSME PFT 1 and transferring energy into PFT 1 . Sub-circuit PWFM switches CLK low turning “off” Q 10 stopping the current into PFT 1 . Energy not transferred into the load is released from NSME PFT 1 into the now forward biased PNP transistor Q 20 back into capacitor C 10 . Thus any energy not used by the secondary loads is transferred back to the primary tank to be used next cycle. When the switching occurs at the resonant frequency large circulating currents develop in the tank. Also C 10 is charged and discharged to very large voltages. Oscillograph in FIG. 35 is the actual voltage developed across capacitor C 10 with VBAT equal to 18 volts. A very large 229-Volts peak to peak was developed across the nodes P 1 A and P 1 A of NSME PFT 1 . The large primary voltage generates large biases in the NSME PFT 1 to be flux harvested by the windings 102 and 103 ( FIG. 18 ) and transferred to a load or rectifier sub-circuit OUTB. Magnetic element winding node S 2 L of sub-circuit PFT 1 is connected to OUTB C 8 b. Magnetic element winding node S 2 H of sub-circuit PFT 1 is connected to C 7 B of sub-circuit OUTB node OUT−. Node OUT− is connected to RLOAD, pin B− and to sub-circuit IFB pin OUT−. Rectified power is delivered to pin OUT+ of OUTB and is connected to RLOAD, pin B+ and to sub-circuit IFB pin OUT+. Sub-circuit IFB provides the isolated feedback signal to the sub-circuit PWFM. Frequency control pin FM 1 of sub-circuit PWFM is connected to sub-circuit IFB pin FBE. Internal reference pin REF of sub-circuit PWFM is connected to sub-circuit IFB pin FBC. PWFM is designed to operate at the resonate frequency of the tank. When sub-circuit IFB senses the converter output is at the designed voltage, current from REF is injected into FM 1 . Injecting current into FM 1 commands PWFM to a lower frequency. Operating below resonance reduces the amount of energy added to the primary tank thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM to 0-Hz all primary activity stops. Input current from VBAT is sinusoidal making the converter very quiet. In addition the switches Q 10 and Q 20 are never exposed to the large circulating voltage (FIG. 35 ). Placing less stress on the switches thereby increasing the MTBF. Sub-circuit TCTP takes advantage of the desirable properties of the NSME in this converter topology. Adjusting secondary turns allows TCTP to generate very large AC or DC output voltages as well as low-voltage high current outputs.
FIG. 9 is a schematic for non-isolated low side switch boost converter sub-circuit NILSBST. Sub-circuit NILSBST consists of resistor R 20 and RLOAD, diode D 16 , capacitor C 6 , FET transistor Q 116 , sub-circuit CP (FIG. 26 ), sub-circuit PFT 1 A (FIG. 18 A), sub-circuit FBI (FIG. 41 ), sub-circuit AMP ( FIG. 29 ) and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+ Resistor R 20 connects to sub-circuit CP pin CP+, sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Resistor R 20 provides startup power to the converter before regulator sub-circuit CP reaches it full 18-volt output. VBAT negative is connected to pin DCIN− and ground return node GND. Node GND connects to sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , Q 111 source, sub-circuit FBA pin BR−, sub-circuit FBA pin FBA, sub-circuit CP pin CT 0 , capacitor C 16 , resistor RLOAD, transistor Q 116 source, and sub-circuit PFT 1 pin S 1 CT. Magnetic element winding node S 1 H of sub-circuit PFT 1 A is connected to CP pin CT 1 A. Magnetic element winding node S 1 CT of sub-circuit PFT 1 is connected to CP pin CT 0 . Magnetic element winding node S 2 H of sub-circuit PFT 1 A is connected to CP pin CT 2 A. The regulated 18 volts from sub-circuit CP+ is connected to R 20 , sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit PWFM is designed for variable pulse width operation. PWFM is configured for maximum pulse width 90-95% (maximum boost voltage) with no feedback current from sub-circuit FBI. Increasing the feedback current reduces the pulse-width reducing the boost voltage and reducing the output from converter NILSBST. Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP. Output of sub-circuit AMP pin GA 2 is connected to the gate of Q 116 . Input node DCIN+ connects to the NSME PFT 1 A pin P 1 A. The drain of Q 116 is connected to sub-circuit PFT 1 A pin P 1 B and the anode of D 16 . Cathode of diode D 16 is connected to sub-circuit FBA pin PF+, resistor RLOAD, C 6 and pin BK+. With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 116 . Switch Q 116 conducts reverse biasing diode D 16 capacitor C 16 stops charging through NSME PFT 1 A from source VBAT. During the time Q 116 is conducting, energy is stored in NSME sub-circuit PFT 1 A. Feedback output pin FBC from sub-circuit FBI is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . Sub-circuit FBI removes current from PW 1 commanding PWFM to reduce the pulse-width or on time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PFFM switches CLK low turning “off” Q 116 stopping the current into PFT 1 A. The energy not transferred into regulator sub-circuit CP load is released from NSME PFT 1 A into the now forward biased diode D 16 charging capacitor C 16 . By modulating the “on” time of switch Q 116 the converter boost voltage is regulated. Regulated voltage is developed across Nodes B− and B+. Sub-circuit IFB provides the feedback current to the sub-circuit PWFM. When sub-circuit IFB senses the converter output (nodes B+ and B−) is at or greater than the designed voltage, current is removed from PW 1 . Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 116 is removed stopping all boost activity capacitor C 16 charges to VBAT. Input current from VBAT is sinusoidal making the converter very quiet. In addition the switch Q 116 is not exposed to large flyback voltage. Placing less stress on the switches thereby increasing the MTBF. Sub-circuit NILBK takes advantage of the desirable properties of the NSME in this converter topology. Adjusting the NSME 100 ( FIG. 18A ) primary inductance and component values in sub-circuit IFB determines the output boost voltage.
›ADDITIONAL EMBODIMENTS · 8 of 30
FIG. 10 is a schematic for a two stage isolated DC to DC boost controlled push-pull converter BSTPP. Sub-circuit BSTPP consists of diode D 14 , capacitor C 14 , FET transistor Q 14 , sub-circuit REG (FIG. 36 ), sub-circuit BL 1 (FIG. 18 B), sub-circuit IFB (FIG. 40 B), sub-circuit AMP (FIG. 29 ), sub-circuit DCAC 1 , sub-circuit OUTB, and sub-circuit PWFM (FIG. 33 ). External power source VBAT connects to pins DCIN+ and DCIN−.
From pin DCIN+ connects to sub-circuit REG pin RIN+ and sub-circuit BL 1 pin P 1 A. Voltage regulator sub-circuit output pin +18V connects to sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit REG provides regulated low voltage power to the controller and to the main switch buffers. VBAT negative is connected to pin DCIN− and ground return node GND. Node GND connects to sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , Q 14 source, capacitor C 14 , sub-circuit IFB pin FBE, sub-circuit REG pin REG 0 and sub-circuit DCAC 1 pin DC−. Sub-circuit PWFM ( FIG. 33 ) is designed for variable pulse width operation. The nominal frequency is between 20-600 Khz PWFM is configured for maximum pulse width 90% (maximum boost voltage) with no feedback current from sub-circuit FBI. Increasing the feedback current reduces the pulse-width reducing the boost voltage and reducing the output from converter BSTPP. Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP (FIG. 29 ). The output of switch speed up buffer sub-circuit AMP pin GA 2 is connected to the gate of Q 14 . Input node DCIN+ connects to the NSME BL 1 pin P 1 A. The drain of Q 14 is connected to sub-circuit BL 1 pin P 1 B and the anode of D 14 . Cathode of flyback diode D 14 is connected to sub-circuit DCAC 1 pin DC+ and C 14 . With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 14 . Switch Q 14 conducts reverse biasing diode D 14 capacitor C 14 stops charging through NSME BL 1 from source VBAT. During the time Q 14 is conducting, energy is stored in NSME sub-circuit BL 1 . Feedback output pin FBC from sub-circuit IFB is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . Sub-circuit IFB removes current from PW 1 commanding PWFM to reduce the pulse-width or “on” time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PFFM switches CLK low turning “off” Q 14 stopping the current into BL 1 . The energy is released from NSME BL 1 into the now forward biased flyback diode D 14 charging capacitor C 14 . By modulating the “on” time of switch Q 14 the converter boost voltage is regulated. Regulated voltage is developed across C 14 Nodes DC+ and GND is provided to the isolated constant frequency push-pull DC to AC converter sub-circuit DCAC 1 (FIG. 2 ). Sub-circuit DCAC 1 provides efficient conversion of the regulated boost voltage to a higher or lower voltage set by the magnetic element-winding ratio. The center tap of the push-pull output magnetic is connected to, sub-circuit OUTB pin OUT−, RLOAD, sub-circuit IFB pin OUT− and the pin OUT− forming the return line for the load and feedback network. Output of sub-circuit DCAC 1 pin ACH is connected to sub-circuit OUTB pin C 7 B. Output of sub-circuit DCAC 1 pin ACL is connected to sub-circuit OUTB pin C 8 B. Sub-circuit OUTB provides rectification of the AC power generated by sub-circuit DCAC 1 . Since the non-saturating magnetic converter has low output ripple, minimal filtering is required by OUTB. This further reduces cost and improves efficiency as losses to filter components are minimized. Sub-circuit IFB provides the isolated feedback current to the sub-circuit PWFM. When sub-circuit IFB senses the converter output (nodes OUT+ and OUT−) is greater than the designed/desired voltage, current is removed from node PW 1 . Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 14 is removed stopping all boost activity capacitor C 14 charges to VBAT. As the non-saturating does not saturate the destructive noisy current “spikes” common to prior art are absent. Input current from VBAT to charge C 14 is sinusoidal making the converter very quiet. In addition the switch Q 14 is not exposed a potentially destructive current spike. Placing less stress on the switches thereby increasing the MTBF. Sub-circuit BSTPP takes advantage of the desirable properties of the NSME. Adjusting the NSME BL 1 ( FIG. 18B ) sets the amount of boost voltage available to the final push-pull isolation stage. Greater efficiencies are achieved at higher voltages. The final output voltage is set by the feedback set point and the turns ratio of the push-pull element PPT 1 (FIG. 19 ).
FIG. 11 is a graph of permeability as a function of temperature for typical prior art magnetic element material. The high permeability material in FIG. 11 exhibits large changes in permeability of almost 100% over a 100 C range as compared to the less than 5% change for the material in FIG. 17 . The increase in permeability at high temperatures of the prior art material increases the flux density resulting in core saturation for a constant power level. (See FIG. 12 ) Thus the prior art core must be derated at least 100% to operate over extended temperatures. The instant invention takes advantage of the desirable properties of the NSME. Eliminating the need to derate the magnetic element. As the magnetic element performs better at high temperatures, currently limited by melting wire insulation.
FIG. 12 is a graph of flux density as a function of temperature for typical prior art magnetic element material. The reduction of maximum flux density with temperature is typical of the saturating magnetic element prior art material. Thus the prior art core is commonly derated at least 100% to operate over extended temperatures. Resulting in a larger more expensive design, and or the requirement to cool the core. FIG. 12A is a graph of magnetic element losses for various flux densities and operating frequencies typical of prior art magnetic element material.
›ADDITIONAL EMBODIMENTS · 9 of 30
FIG. 13 is a graph showing standard switching losses. The hashed area represents the time when the switch is in a resistive state. The hashed area is proportional to the amount of energy lost each time the output switch operates. Total power lost is the product of the loss per switch times the switching frequency.
FIG. 14 is a graph showing the inventions switching losses. The hashed area represents the time when the switch is in a resistive state. The smaller hashed area is due to the action of the buffer in FIG. 29 and the snubber isolation diode D 805 in FIG. 30 . Generally the NSME has a wider usable frequency band and can be magnetized from higher primary voltages. Higher operating voltages have proportionally smaller currents for a given power level thus proportionally lower losses. Switching losses more closely resemble I 2 R losses. Most switching loss occurs during turn “on” and turn “off” transitions; total switching losses are reduced proportionally by the lower switching frequencies and faster transition times characteristic of the disclosed NSME converters. In addition the properties of the NSME allow operation at temperature extremes beyond the tolerance of standard prior art magnetics and their geometry's. The combined contributions of the above yields a converter that requires little or no forced air-cooling. (See FIGS. 16 and 17 )
FIG. 15A is a graph of the magnetization curves for H Material.
FIG. 16 is a graph of the Kool Mu NSME losses for various flux densities and operating frequencies. It can be seen from the data that much higher flux densities are available per unit losses over the prior art.
FIG. 17 is a plot of permeability vs. temperature for several Kool Mu materials. This data demonstrates the usefulness and stability of the magnetic properties over temperature.
FIG. 18 is a schematic representation of the non-saturating magnetic boost element PFT 1 . Sub-circuit PFT 1 consists of a primary winding 100 around a NSME 101 with two center-tapped windings 102 and 103 .
The primary winding 100 has nodes P 1 B and P 1 A for connections to external AC source. Secondary 102 winding has center-tapped node S 1 CT and node S 1 H and S 1 L connections to the upper and lower halves respectively. Secondary 103 winding has center-tapped node S 2 CT and node S 2 H and S 2 L connections to the upper and lower halves respectively. Both 102 and 103 are connected to external full-wave rectifier assemblies. Magnetic element magnetic element 101 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which ranges from 1500 to 5000 u. Flyback management is of concern when using NSME in a boost converter because the magnetic element generates high drain source voltages across the primary switch during the reverse recovery time of the flyback (output) diode. The magnitude per cycle of flyback current from NSME is greater for a given input magnetizing force relative to the prior art. (See FIG. 5 ) For example, Kool Mu torroids (Materials from Magnetics) are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight, 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air, (permeability=1); a molypermalloy powder, (MPP) a high flux MPP, a powder, a gapped ferrite, a tape wound, a cut magnetic element, a laminated, or an amorphous magnetic element. Unlike the prior art, the NSME is temperature tolerant in that the critical parameters of permeability and saturability remain substantially unaffected during extreme thermal operation over time. Some materials such as air also exhibit little or no change in permeability or saturation levels over time, temperature, and conditions. The prior art uses high permeability saturable materials often greater than 2000 u permeability. These magnetics exhibit undesirable changes in permeability and saturation during operation at or near rated output making operation at high power levels and temperature difficult. See the permeability vs. temperature FIG. 11 . This deficiency is overcome by the use of expensive oversized magnetic elements or output current sharing with multiple supplies. (See the graph b sat vs. temperature FIG. 12 ) This invention takes advantage of the desirable properties of NSME. See the permeability vs. temperature FIG. 17 . Prior art saturating magnetic element commonly is operating at frequencies greater than 500 KHz to achieve greater power levels. As a result practitioners experience exponentially greater core losses (see FIG. 12A ) at high frequencies. NSME support operation at lower frequencies 20-600 KHz further reducing switching losses and magnetic element losses allowing operation at even higher temperatures. See the loss density vs. flux density FIG. 16 . Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses. The magnetic element is operated at duty cycles of 0%+ to 90%, which, when used to control the primary side push-pull voltage, results in efficiencies on the order of 90%.
FIG. 18A is a schematic representation of the NSME PFT 1 A Sub-circuit transformer PFTlA consists of a primary winding 100 around a NSME 101 with a center-tapped winding 102 .
The primary winding 100 has nodes P 1 B and P 1 A for connections to external AC source. Secondary 102 winding has center-tapped node S 1 CT and node S 1 H and S 1 L connections to the upper and lower halves respectively. Winding 102 are typically connected to external full-wave rectifier assemblies. Magnetic element 101 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which is on the order of 2500 u.
›ADDITIONAL EMBODIMENTS · 10 of 30
Flyback management is of concern when using such a magnetic element because the magnetic element generates high drain source voltages across the primary switch during the reverse recovery time of the flyback diode. Flyback current is available for longer periods after the primary switch opens. (See FIG. 5 ) For example, Kool Mu (Materials from Magnetics are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight: 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air; (air magnetic element permeability=1); a molypermalloy powder (MPP) magnetic element; a high flux MPP magnetic element; a powder magnetic element; a gapped ferrite magnetic element; a tape wound magnetic element; a cut magnetic element; a laminated magnetic element; or an amorphous magnetic element. During operation the temperature of the NSME rises, the permeability slowly decreases, thereby increasing the saturation point. Some materials such as air exhibit no or very small changes in permeability or saturation levels. Unlike prior art using high permeability materials greater than 2000 u permeability rapidly increases at high temperatures. See the permeability vs. temperature FIG. 11 . Prior art also suffers from reduced magnetic element saturation levels at high temperatures, making operation at high power levels and temperature difficult and may require the use of expensive oversized magnetic elements. See the graph b sat vs. temperature FIG. 12 this invention takes advantage of the desirable NSME properties. See the permeability vs. temperature FIG. 17 . Operation at lower frequencies 20-600 KHz reduces switching losses and magnetic element losses allowing operation at higher temperatures. See the loss density vs. flux density FIG. 16 . Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses. The magnetic element is operated at duty cycles of 0%+ to 90%, which, when used to control the primary side push-pull voltage, results in efficiencies on the order of 90%.
FIG. 18B is a schematic representation of the NSME BL 1 Sub-circuit BL 1 consists of a winding 100 around a NSME 101 .
Magnetic element BL 1 may also be constructed from one or more magnetic elements in series or parallel. Assuming minimal mutual coupling the total inductance is the arithmetic sum of the individual inductances. For elements in parallel (assuming minimal mutual coupling) the total inductance is the reciprocal of the arithmetical sum of the reciprocal of the individual inductances. In this way multiple magnetic elements may be arranged to meet packaging, manufacturing, and power requirements. The primary winding 107 has nodes P 2 B and P 2 A for connections to external AC source. Magnetic element 107 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which is on the order of 2500 to 5000 u. Flyback management is of concern when using such a magnetic element because the magnetic element generates high drain source voltages across the primary switch during the reverse recovery time of the flyback diode. Flyback current is available for longer periods after the primary switch opens. (See FIG. 5 ) For example, Kool Mu (Materials from Magnetics are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight: 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air (air magnetic element permeability=1); a molypermalloy powder (MPP) magnetic element; a high flux MPP magnetic element; a powder magnetic element; a gapped ferrite magnetic element; a tape wound magnetic element; a cut magnetic element; a laminated magnetic element; or an amorphous magnetic element. During operation temperature of the magnetic element rises, the permeability slowly decreases, thereby increasing the saturation point. Some materials such as air exhibit no or very small changes in permeability or saturation levels. Unlike prior art using high permeability materials greater than 2000 u permeability rapidly increases at high temperatures. See the permeability vs. temperature (FIG. 11 ). Prior art also suffers from reduced magnetic element saturation levels at high temperatures, making operation at high power levels and temperature difficult and may require the use of expensive oversized magnetic elements. (See the graph b sat vs. temperature FIG. 12 ) This invention takes advantage of the desirable NSME properties. (See the permeability vs. temperature FIG. 17. ) Prior art often operates at high switching frequencies 100-1000 kHz to avoid the saturation problem. Only to increase switching and core losses. (See FIG. 12A ) This inventions use of the desirable NSME properties allows operation at lower frequencies 20-600 KHz further reducing switching losses and magnetic element. See the loss density vs. flux density FIG. 16 . Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses.
FIG. 18C is a schematic representation of a distributed NSME PFTLD. This is shown to exemplify distributed magnetics enable advantageous high voltage converter design variations that support form factor flexibility and multiple parallel secondary outputs from series coupled voltage divided primary windings across multiple NSME. This magnetic strategy is useful in addressing wire insulation, form factor and packaging limitations, circuit complexity and manufacturability. In this example a 500W converter is required to fit in a low profile package. Sub-circuit PFTD 1 consists of three magnetic elements 120 , 121 and 124 with series connected primaries.
›ADDITIONAL EMBODIMENTS · 11 of 30
AC voltage is applied to 112 pin P 1 B then from P 1 C through conductor 115 to 116 pin P 1 D. Winding 116 pin P 1 E is connected through conductor 119 to 118 pins P 1 F then to pin P 1 A. Original Sub-circuit PFT 1 ( FIG. 18 ) consists of a primary winding 100 around a NSME 101 with two center-tapped windings 122 and 123 . By way of example sub-circuit PFT 1 D will be implemented as three magnetic elements. For a 500-watt expression a total inductance of 203 uH is required in winding 100 (FIG. 18 ). Dividing the primary inductance by the number of elements, in this case three requires elements 112 , 116 and 118 have 67 uH of inductance. The energy storage is equally distributed over the magnetic assembly 120 , 121 and 124 . The 500 watt converter in ( FIG. 1 ) employs two (Kool Mu part number 77932-A7) 0.9 oz (25 gram) NSME to form 101 (FIG. 18 ). Sub-circuit PFT 1 magnetic element 101 ( FIG. 18 ) may be expressed as three 0.5-0.7 oz (14-19 gram) elements. Three 0.5-oz Kool Mu elements (part number 77352-A7) were selected. To realize 67 uH of primary inductance 55 turns are required for elements 112 , 116 and 118 . The primary circuit has nodes P 1 B and P 1 A for connections to external AC source. Secondary 122 winding has center-tapped node S 1 CT and node S 1 H and S 1 L connections to the upper and lower halves respectively. Secondary 123 winding has center-tapped node S 2 CT and node S 2 H and S 2 L connections to the upper and lower halves respectively. Both 122 and 123 are connected to external full-wave rectifier assemblies. Magnetic element magnetic element 120 , 121 and 124 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which is on the order of 2500 u. Flyback management is of concern when using such a magnetic element because the magnetic element generates high drain source voltages across the primary switch during the reverse recovery time of the flyback diode. Flyback current is available for longer periods after the primary switch opens. (See FIG. 5 ) For example, Kool Mu (Materials from Magnetics are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight: 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air (air magnetic element permeability=1); a molypermalloy powder (MPP) magnetic element; a high flux MPP magnetic element; a powder magnetic element; a gapped ferrite magnetic element; a tape wound magnetic element; a cut magnetic element; a laminated magnetic element; or an amorphous magnetic element. During operation the temperature of the NSME, the permeability slowly decreases, thereby increasing the saturation point. Some materials such as air exhibit no or very small changes in permeability or saturation levels. Unlike prior art using high permeability materials greater than 2000 u permeability rapidly increases at high temperatures. See the permeability vs. temperature FIG. 11 . Prior art also suffers from reduced magnetic element saturation levels at high temperatures, making operation at high power levels and temperature difficult and may require the use of expensive oversized magnetic elements. (See the graph b sat vs. temperature FIG. 12 ) This invention takes advantage of the desirable NSME properties. See the permeability vs. temperature FIG. 17 . Prior art saturating magnetic element commonly is operating at frequencies greater than 500 KHz to achieve greater power levels. As a result practitioners experience exponentially greater core losses (see FIG. 12 A) at high frequencies. NSME allows operation at lower frequencies 20-500 KHz further reduces switching losses and magnetic element losses allowing operation at even higher temperatures. (See the loss density vs. flux density FIG. 16 ) Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses. The magnetic element is operated at duty cycles of 0%+ to 90%, which, when used to control the primary side push-pull voltage, results in efficiencies on the order of 90%.
FIG. 19 is a schematic representation of the non-saturating push-pull magnetic element sub-circuit PPT 1 .
Sub-circuit PPT 1 consists of a center-tapped primary winding 104 around a NSME 106 with one secondary center-tapped winding 105 .
The primary winding 104 has nodes P 2 H and P 2 L for connections to external AC sources, and common center-tap node P 2 CT. Secondary 105 winding has center-tapped node SCT and nodes SH and SL connections to the upper and lower halves respectively. The invention is not limited to a single output. More secondary windings may be added for additional outputs. Secondary 105 is connected to an external full-wave rectifier assembly (Example FIG. 25 or 26 ). The magnetic element magnetic element 106 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which is on the order of 2500 u. Flyback management is of concern when using such a magnetic element as high drain source voltages across the primary switch are generated during the reverse recovery of the flyback diode. The falling flyback current is available for a longer period. (See FIG. 5 ) For example, Kool Mu (magnetic elements from Magnetics are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight; 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air (comprise an air magnetic element); a molypermalloy powder (MPP) magnetic element; a high flux MPP magnetic element; a powder magnetic element; a gapped ferrite magnetic element; a tape wound magnetic element; a cut magnetic element; a laminated magnetic element; or an amorphous magnetic element. During operation the temperature of the NSME rises, the permeability slowly decreases, thereby increasing the saturation point. Unlike prior art using high permeability materials greater than 2000 u permeability rapidly increases at high temperatures. See the permeability vs. temperature FIG. 11 . Prior art also suffers from reduced magnetic element saturation levels at high temperatures, making operation at high power levels and temperature difficult and may require the use of expensive oversized magnetic elements. (See the bsat vs. temperature FIG. 12 ) This invention takes advantage of the desirable NSME properties. (See the permeability vs. temperature ( FIG. 17 ) Operation at lower frequencies 20-600 KHz reduces switching losses and magnetic element losses allowing operation at higher temperatures. See the loss density vs. flux density FIG. 16 . Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses. The magnetic element primary is driven in a push-pull fashion at a duty cycle of 48-49% resulting in efficient use of the magnetic element volume.
›ADDITIONAL EMBODIMENTS · 12 of 30
FIG. 19A is a schematic representation of the non-saturating push-pull magnetic element sub-circuit PPT 1 . Sub-circuit PPT 1 consists of a center-tapped primary winding 134 around a NSME 136 with one secondary center-tapped winding 135 .
The primary winding 134 has nodes P 2 H and P 2 L for connections to external AC sources, and common center-tap node P 2 CT. Secondary 135 winding has center-tapped node SCT and nodes SH and SL connections to the upper and lower halves respectively. The invention is not limited to a single output winding. More secondary windings may be added for additional outputs. Secondary 135 is connected to an external full-wave rectifier assembly such as OUTA (FIG. 25 ), OUTB ( FIG. 25A ) and OUTBB (FIG. 25 B). The magnetic element 136 comprises a non-saturating, low permeability magnetic material. The permeability is on the order of 26 u with a range of 1 u to 550 u, as compared to the prior art, which is on the order of 2500 u. Flyback management is of concern when using such a magnetic element as high drain source voltages across the primary switch are generated during the reverse recovery of the flyback diode. The falling flyback current is available for a longer period. (See FIG. 5 ) For example, Kool Mu (magnetic elements from Magnetics are suitable for this application. This material is not identified by way of limitation. The material comprises, by weight; 85% iron, 6% aluminum, and 9% silicon. Further, the magnetic element may be air (comprise an air magnetic element); a molypermalloy powder (MPP) magnetic element; a high flux MPP magnetic element; a powder magnetic element; a gapped ferrite magnetic element; a tape wound magnetic element; a cut magnetic element; a laminated magnetic element; or an amorphous magnetic element. During operation the temperature of the NSME rises, the permeability slowly decreases, thereby increasing the saturation point. Unlike prior art using high permeability materials greater than 2000 u permeability rapidly increases at high temperatures. See the permeability vs. temperature (FIG. 11 ). Prior art also suffers from reduced magnetic element saturation levels at high temperatures, making operation at high power levels and temperature difficult and may require the use of expensive oversized magnetic elements. (See the bsat vs. temperature FIG. 12 ) This invention takes advantage of the desirable NSME properties. (See the permeability vs. temperature FIG. 17 ) Operation at lower frequencies 20-600 KHz reduces switching losses and magnetic element losses allowing operation at higher temperatures. See the loss density vs. flux density FIG. 16 . Unlike the prior art, the instant invention uses voltage mode control with over-current shutdown. Material selection is also based upon mass and efficiency. By increasing the mass of the magnetic element, more energy is coupled more efficiently. Since there are reduced losses, the dissipation profile follows I2R/copper losses. The magnetic element primary is driven in a push-pull fashion at a duty cycle of 48-49% resulting in efficient use of the magnetic element volume.
FIG. 20 is a schematic showing the inventions filter and lightning input protection circuit for an AC line connected converter. The protection sub-circuit LL comprises a Spark gap A 1 , diodes D 20 and D 21 , capacitor C 1 and magnetic elements L 1 and L 2 .
The AC line is connected to node LL 2 . The common input frequencies of DC to 440 Hz may be extended beyond this range with component selection. Node LL 2 is connected to NSME L 1 then to node LL 5 , the spark gap A 1 , anode of diode D 22 and the cathode of diode D 20 . Filter capacitor C 60 is connected between node LL 0 and LL 6 . Filter capacitor C 61 is connected between node LL 0 and LL 5 . The low side of AC line is connected to node LL 1 then to magnetic element L 2 the other side L 2 is connected to spark gap A 1 , anode of diode D 23 and the cathode of diode D 21 and to node LL 6 . Capacitor C 1 is connected to earth ground C 1 attenuates noise generated by the converter. The use of non-saturating magnetic allows the input magnetic elements to absorb very large voltages and currents commonly generated by lightning, often without causing spark gap A 1 to clamp. During UL testing sixty 16 ms 2000V pulses were applied between LL 1 and LL 2 without realizing spark gap A 1 was missing with out damage. During normal operation the NSME L 1 flux density is a few hundred gauss. Elements L 1 and L 2 will block differential or common mode line transients. In the event of a very large or long duration line to neutral transient, spark gap A 1 will clamp the voltage to a safe level of about 400V. The NSME L 1 and L 2 have the added benefit of reducing conducted noise generated by the converter.
FIG. 20A is a schematic showing an alternate line filter. The filter sub-circuit LF comprises capacitors C 2 and C 60 - 66 , inductors L 64 and L 62 , magnetic element L 63 and diodes D 20 -D 23 .
The AC line is connected to nodes LL 2 and LL 1 . Node LL 2 connects through upper leg of inductor L 64 to first leg of y-cap C 64 then to capacitor C 63 then to upper leg of Bifilar wound inductor L 62 . Node LL 1 connects through lower leg of inductor L 64 to second leg of y-cap C 65 , then to capacitor C 63 then to lower leg of Bifilar wound inductor L 62 . Capacitor C 66 is connected between LL 2 and LL 1 . Second upper leg of inductor L 62 connects to first leg of y-cap C 61 then to capacitor C 62 then to anode of D 22 and cathode of D 20 . Second lower leg of inductor L 62 connects to second leg of y-cap C 60 then to capacitor C 62 then to anode of D 23 and cathode of D 21 . Center legs of Y-caps C 60 , C 61 , C 64 and C 65 are connected to chassis return LL 0 . Capacitor C 69 connects node BR− to chassis ground LL 0 . Anodes of diode D 20 and D 21 connected to node BR−. Cathodes of diodes D 22 and D 23 connect to MSME L 63 in parallel with C 20 and node BR+. Capacitor C 21 connects to BR− and the other side of L 63 in parallel with C 20 forming node B+. Common mode inductors L 64 and L 62 are constructed on a high permeability core material H41-406-TC, H42-109-TC respectively manufactured by Magnetics inc. Butler Pa. USA. This material is offered by way of example and not limitation. Capacitor C 69 is connected to earth ground attenuates noise generated by the converter. The instant invention takes advantage of the high permeability properties of the ferrite used in inductors L 64 and L 62 . (see FIG. 15 A). Making full use of the core material over all four quadrants. Inductors L 64 and L 62 are effective in removing common mode EMI components. Differential mode noise generated by the main switch Q 1 is effectively blocked by NSME L 63 in parallel with C 20 . Inductor L 63 is operated in the first quadrant taking advantage of the unique non-saturating properties of the Kool Mu core material(manufactured by Magnetics Inc.). This material allows operation with large DC magnetizing currents without saturation. NSME L 63 in parallel with C 20 forms a tuned tank effectively blocking high frequency from the AC line. Elements L 64 and L 62 will block common mode line transients. In the event of a very large or long duration line to neutral transient, sub-circuit TRN ( FIG. 46 ) connected to BR+ redirects the transient into the main storage capacitor C 442 . The instant invention makes optimal use of the ferrite type material in the AC side and the desirable NSME in the DC side to provide high performance filtering at a low cost.
›ADDITIONAL EMBODIMENTS · 13 of 30
FIG. 21 is a schematic showing the inventions alternate lightning protection sub-circuit LLA for an AC line connected converter. The protection circuit comprises a , Spark gap A 1 , capacitors C 1 , C 60 and C 61 and NSME L 3 .
High side of AC line is connected to node LL 2 is connected to NSME L 3 and to capacitor C 61 . The load side L 3 is connected to spark gap A 1 and the cathode of diode D 20 and anode of D 22 forming node LL 5 . The low side of AC line is connected to node LL 6 , capacitor C 60 , spark gap A 1 , and the cathode of diode D 21 and anode of D 23 . The anodes of diodes D 20 and D 21 are connected to Capacitor C 1 . Capacitor C 1 is connected to earth ground. C 1 attenuates radiated noise or EMI generated by the converter. The cathode of diodes D 22 and D 23 are connected to Capacitor C 2 . Capacitor C 2 decouples high frequency harmonic currents from the line. Capacitors C 1 , C 61 and C 60 are connected to earth ground node LL 0 . The use of non-saturating magnetics allows the input magnetic element to absorb very large voltages and currents commonly generated on the AC line by lightning. A transient on the AC line will be limited by capacitors C 60 and C 61 and blocked by the non-saturating magnetic L 3 . In the event of a very large or long duration line to neutral transient, magnetic element L 3 will allow the voltage to rise across spark gap A 1 , the spark gap will clamp the voltage to a safe level protecting the rectifier diodes D 20 -D 23 . The NSME L 3 has the added benefit of reducing conducted noise generated by the converter. C 1 connected to the ground plane is effective in attenuating conducted and radiated EMI.
FIG. 22 is a schematic showing the inventions AC line rectifier. The rectifier sub-circuit BR 1 comprises diodes D 20 , D 21 , D 22 and D 23 and capacitor C 2 .
An AC or DC signal from the input filter is connected to bridge rectifier to nodes BR 1 and BR 2 . Node BR 1 connects diode D 22 anode to D 20 cathode. Node BR 2 connects diode D 23 anode to D 21 cathode. Node BR+ connects diode D 22 cathode to D 23 cathode. Node BR− connects diode D 20 anode to D 21 anode. The common input frequencies of DC to 440 Hz may be extended beyond this range with component selection. Capacitor C 2 is selected to improve power factor for a particular operating frequency and to de-couple switching currents from the line. Diodes are selected to reliably block the expected line voltage and current demands of the next converter stage.
FIG. 23 is the inventions AC to DC controller sub-circuit. Sub-circuit PFA consists of resistors R 313 and R 316 , capacitors C 308 , and C 313 and PWM controller IC U 1 A.
Control element U 1 A connects to a circuit with the following series connections: from pin 1 to feedback node/pin PF 1 then to capacitor C 308 then to the pin 2 node of U 1 A. Internal 5.1-volt reference U 1 A pin 8 or node PFA 2 through resistor R 308 to the pin 4 node. U 1 A pin 4 is connected through capacitor C 313 to return node BR−. This arrangement allows the PFC output to be pulse width modulated with application of voltage to PF 1 . External feedback current applied to U 1 A pin 1 and node PF 1 . Node PFVC is connected to resistor R 313 to pin 3 of U 1 A. Resistor R 316 is connected to pin 3 then to return node BR− Power pin 7 is connected to node PFA+. Control element switch drive U 1 A pin 6 is connected to node PFCLK. Return ground node of U 1 A pin 5 is connected to return node BR−. In the event of a component failure in the primary feed networks such as IPFFB (FIG. 40 ), FBA (FIG. 40 A), IFB ( FIG. 40B ) and FB 1 (FIG. 41 ). The output voltage of the boost stage may rapidly increase to destructive levels. Fast over voltage feedback networks IOVFB ( FIG. 40C ) or OVP 2 ( FIG. 42B ) increases the current into PF 1 thereby limiting the output voltage to a safe level. In addition latching type over voltage protection networks such as OVP (FIG. 42 ), OVP 1 ( FIG. 42A ) and OVP 2 ( FIG. 42B ) maybe used. The latching type kills power to the control circuit thereby stopping the boost action. The latching type networks require power to be cycled to the converter to reset the latch. IFB Input node PFVC is connected to resistor R 313 to internal zero crossing detector connected to pin 3 and through R 316 to return node BR−. PFVC is connected to a magnetic element winding referenced to BR−. A new conduction cycle is started each time the bias in the magnetic element goes to zero. Power factor corrected is realized by chopping the input at a high frequency. The average pulse width decreases at higher line voltage and increases at lower voltage for a given load. Frequency is lower at line peaks and higher around zero crossings. In this way the converter operates with a high input power factor.
FIG. 24 is the alternate power factor controller sub-circuit. Sub-circuit PFB consists of resistors R 313 , R 339 , R 314 , R 315 , R 328 , R 340 , R 341 and R 346 , diode D 308 , capacitors C 310 , C 318 , C 338 , C 340 , C 341 and C 342 , transistor Q 305 , and control element IC U 1 B.
Control element U 1 B connects to a circuit with the following series connections: from pin 1 to node/pin PF 1 to capacitor C 338 in series with resistor R 339 , and then to the pin 2 node of U 1 B. Pin 1 is the input to an internal error amplifier and connection to external feedback networks. (See FIGS. 40 , 40 A, 40 B, 40 C, 40 D and 41 ) Increasing the voltage on pin 1 decreases the pulse width of the PFCLK node pin 7 . Resistor R 328 is connected to the fullwave rectified AC line haversine voltage on node BR+ then to U 1 B pin 3 and then to resistor R 346 in parallel with capacitor C 342 to return node BR−. Node PFSC connects to series resistors [R 341 +R 340 ] which are connected to U 1 B pin 4 then to diode D 308 in parallel with capacitor C 340 to return node BR−. Power to PFC controller is applied to node PFB+ and to U 1 B pin 8 . Output clock node PFCLK is connected to U 1 B pin 7 , to external buffer sub-circuit AMP (FIG. 29 ). Transistor Q 305 collector is connected to the pin 2 node of U 1 B. The base is connected in series through resistor R 314 to capacitor C 318 , then to the pin 2 node of U 1 B. The base is also connected to [C 310 ∥R 315 ], then to return node BR− Emitter of Q 305 is connected to return node BR−. Transistor Q 305 provides a soft start compensation ramp to the controller error amp reducing the stress and DC overshoot in the converter at power up. Capacitor C 341 is connected from U 1 pin 2 to return node BR−. U 1 B pin 1 is connected to pin PF 1 , capacitor C 338 in series with resistor R 339 to transistor Q 305 collector and to U 1 pin 2 . Current switched by PFC power switch Q 1 ( FIGS. 4 & 3 ) is sensed by R 26 (see FIG. 4 ). Series resistors [R 340 +R 341 ] to U 1 B pin 4 connect voltage developed across R 26 . This voltage is compared to an internal 1.5-volt reference, comparator output turns off the switch drive pin 7 of U 1 B during times of high current that occur during startup or during very high load or low line conditions. Capacitor C 340 is connected between U 1 pin 4 to return node BR− filter high frequency components. Schottky diode D 308 connected between U 1 pin 4 to return node BR− protects the controller (U 1 pin 4 ) substrate from negative current injection. Maximum switch current value is set by R 26 over currents are automatically limited in each cycle by the PFC controller. The rectified fullwave haversine at pin 3 of U 1 B is multiplied by the error voltage on pin 2 . The product is compared to the magnetic element/switch current measured by R 26 on pin 4 . Gate drive on pin 7 turns off when the sensed magnetic element current increases to the current comparator level. This action has the effect of modulating the switch Q 1 “on” time tracking the AC line voltage. External feedback networks are connected to node PF 1 . In the event of a component failure in the primary feed network such as IPFFB (FIG. 40 ), FBA (FIG. 40 A), IFB ( FIG. 40B ) and FB 1 (FIG. 41 ). The output voltage of the boost stage may rapidly increase to destructive levels. Fast over voltage feedback networks IOVFB ( FIG. 40C ) or OVP 2 ( FIG. 42B ) increases the current into PF 1 thereby limiting the output voltage to a safe level. In addition latching type over voltage protection networks such as OVP (FIG. 42 ), OVP 1 ( FIG. 42A ) and OVP 2 ( FIG. 42B ) maybe used. The latching type removes power to the control circuit thereby stopping the boost action. The latching type networks require power to be cycled to the converter to reset the latch. Modulating the voltage at PF 1 changes the duty cycle of the PFC and the final output voltage. In this way the PFC may be used as a pre-regulator to additional output stages.
›ADDITIONAL EMBODIMENTS · 14 of 30
FIG. 25 is a schematic of a full wave rectified output stage and filter sub-circuit OUTA. The rectifier stage consists of diodes D 80 and D 90 . The filter consists of resistor R 21 , magnetic element L 30 and capacitors C 26 , C 27 , C 28 , C 29 , C 30 , C 31 and C 32 .
Input node/pin C 7 B is connected to the high side of external center-tapped magnetic element secondary winding. Node C 7 B connects to anode of diode D 8 and to capacitors C 26 and C 27 in the following arrangement. Capacitor C 27 is connected across diode D 80 , capacitor C 26 is connected in series to R 21 . Input node/pin C 8 B is connected to the low side of external center-tapped magnetic element secondary winding. Pin C 8 B is connected to anode of diode D 90 and to resistor R 21 , capacitor C 32 is connected across diode D 90 . Capacitors C 27 and C 32 is a small value to reduce high frequency noise generated by rapid switching the high speed rectifier D 80 and D 90 respectively. Capacitor C 26 and resistor R 21 are used to further dissipate high frequency energy. Anode of diodes D 80 and D 90 is connected to parallel capacitors C 28 ∥C 29 and NSME L 30 . Capacitors C 28 and C 31 are solid dielectric types selected for low impedance to high frequency signals. Capacitors C 29 and C 30 are larger polarized types selected for low impedance at low frequencies and for energy storage. Magnetic element L 3 is connected to diode D 80 cathode the second terminal of L 30 is connected to parallel capacitors C 31 and C 30 and pin OUT+. Node OUT+ is the output positive and is connected to external feedback sense line to isolated feedback network. The other side of parallel capacitors [C 28 ∥C 29 ∥C 30 ∥C 31 ] is connected to pin OUT− and the center-tap of the magnetic element secondary forming the return node. The combination of capacitors [C 28 ∥C 29 ], L 30 and capacitors [C 30 ∥C 31 ] form a low pass pi type filter. Sub-circuit OUTA performs efficient fullwave rectification and filtering.
FIG. 25A is a schematic of a full wave rectified output stage. The rectifier stage consists of diodes D 80 and D 90 and capacitors C 931 and C 928 .
Input node/pin C 7 B is connected to high side of external center-tapped magnetic element secondary winding. Node C 7 B connects to anode of diode D 80 . Input node/pin C 8 B is connected to low side of external center-tapped magnetic element secondary winding is connected to anode of diode D 90 . Node OUT− is the negative output and return line to the external isolated feedback network and load not shown. Cathodes of diodes D 80 and D 90 are connected to parallel capacitors C 931 and C 928 . Capacitor C 928 is a solid dielectric type selected for low impedance to high frequency signals. Capacitor C 931 is a larger polarized selected for low impedance to low frequency signals and for energy storage. Node OUT+ is the output positive and is connected to external feedback sense line to isolated feedback network. The other side of parallel capacitors C 928 ∥C 931 is connected to the center-tap of the magnetic element secondary forming the node OUT−. The use of the NSME for the push-pull magnetic element requires only minimal filtering after the rectifiers.
FIG. 25B is a schematic diagram of an alternate final output rectifier and filter sub-circuit OUTB. The rectifier sub-circuit OUTB comprises diodes D 40 , D 41 , D 42 and D 43 and capacitor C 931 and C 928 .
An AC or DC signal is connected to nodes C 7 B and C 8 b. Node C 7 B connects diode D 41 anode to D 40 cathode. Node C 8 b connects diode D 42 anode to D 43 cathode. Node OUT+ connects diode D 42 cathode to D 43 cathode. Node OUT− connects diode D 40 anode to D 43 anode. Diodes are selected to reliably block the expected line voltage and current demands of the load. For low voltage outputs, Schottky type diodes are used due to their low forward voltage drop. Higher voltages would use high-speed silicon diodes due to their ability to withstand high peak inverse voltage (PIV). The use of the NSME for the push-pull magnetic element requires only minimal filtering after the rectifiers. Capacitor C 928 is shown schematically as a single device. Capacitor C 931 is a larger polarized selected for low impedance to low frequency signals and for energy storage a typical value may be 200 uF. To increase the capacitance or reduces the output impedance multiple capacitors may be used. C 931 is a solid dielectric type and is selected for it's low impedance to high frequencies. As is selected to reduces noise for a particular operating frequency and power level. Capacitor C 928 is selected for the operating frequency and power level. Sub-circuit OUTB performs AC to DC rectification and filtering at slightly lower efficiency due to the extra junctions.
FIG. 26 Floating 18 Volt DC control power sub-circuit CP. Sub-circuit CP consists of diodes D 501 , D 502 and D 503 , resistor R 507 , regulator Q 504 , and capacitors C 503 , C 504 , C 505 , C 506 , and C 507 .
Node CT 1 A connects to anode of D 503 and to the upper external center tapped secondary winding. Node CT 2 A connects to anode of D 502 and to the lower external center tapped secondary winding. Node CT 0 connects to the external winding center tap. Node CT 0 is also the return line and it connects to Q 504 pin 2 , and capacitors C 503 , C 504 , C 505 , C 506 , and C 507 . The cathode of each of diodes D 502 and D 503 is connected to resistor R 507 . R 507 is then connected to the pin 1 (input) node of voltage regulator Q 504 . Voltage regulator Q 504 Pin 3 is the 18 vdc regulated DC output is connected to the anode of blocking diode D 501 . Three-pin voltage regulator Q 504 is of the type LM7818 a common device made by a number of manufacturers. Capacitors C 503 , C 505 , C 506 are 0.1 uF solid dielectric type and are used to filter high frequency ripple and to prevent Q 504 from oscillating. The junction of C 503 , C 504 and D 501 cathode is the output node CP 1 +. Isolated 18-volt DC is available between nodes CT 0 and CP+. Used for regulator circuits and output switch drive during normal operation.
›ADDITIONAL EMBODIMENTS · 15 of 30
FIG. 26A Alternate control power sub-circuit CP 1 Sub-circuit CP 1 consists of diode D 260 , resistor R 261 , transistor Q 260 , and capacitors C 261 -C 265 , and C 260 .
Node CT 1 A connects to anode of D 261 and to the upper external center tapped secondary winding. Node CT 2 A connects to anode of D 262 and to the lower external center tapped secondary winding. Node BR− connects to the external winding center tap. Node BR− is also the return line and it connects to Q 260 emitter, and capacitors C 261 -C 265 and R 261 . The cathode of diodes D 261 and D 262 is connected inductor L 260 and capacitor 266 . The other side of capacitor C 266 connects to node FSC. Resistor R 262 is then connected between the other side of inductor L 260 and node VCC. The junction of R 262 and L 260 forms node TP 15 . Node VCC connects the positive terminals of capacitors C 260 - 265 , collector of Q 260 , and cathode of D 260 . Anode of low leakage zener D 260 connects to the base of Q 260 , resistor R 261 and capacitor C 260 . The zener diode voltage is selected to begin regulation at high boost levels. Thus VCC is allowed to follow the load level as shown by G 26 (FIG. 26 B). Voltage limiting starts at levels near full load (maximum boost). This is offered by way of example and not limitation. In a 1000-watt converter the VCC limiting is observed with the increase in slope at high output power. This unique behavior has three benefits. First at greater levels of boost (load) additional voltage is automatically provided to the main switch Q 1 when maximum gate power is required. Lowering gate voltage at minimal boost reduces the stress on the main switch Q 1 gate and associated buffer components, thus enhancing MBTF and efficiency. Second VCC provides an internal load sense signal used to servo the output voltage for load sharing. The load sharing aspects of the design will be taught in FIG. 4 A. Third, a signal is available that may be used to communicate load magnitude with out additional current sensors. Diodes D 262 and D 261 provide rectified power capacitor C 226 couples AC voltage to node TP 17 of sub-circuit FS 1 (FIG. 45 ). The AC voltage on TP 17 inhibits the action of the fast start circuit when the converter is operating. Regulator CP 1 is a shunt regulator. The components are selected such that the limiting begins near maximum boost. In this way, power is not wasted at small load levels. Additionally the main switch Q 1 gate voltage is modulated to provide additional power at maximum boost insuring maximum efficiency under varying load conditions.
FIG. 26B is a plot of VCC as a function of output power. Plot G 26 was generated by measuring VCC in ACDCPF 1 ( FIG. 4A ) as the load was veried from 0-1000 watts.
FIG. 27 second Floating 18_Volt DC push-pull control power sub-circuit CPA. Sub-circuit CPA consists of diodes D 601 , D 602 and D 603 , resistor R 607 , regulator B 604 and capacitors C 603 , C 604 , C 605 , C 606 , C 607 and C 608 .
Node CT 1 B connects to anode of D 603 and to the upper external center tapped secondary winding. Node CT 2 B connects to anode of D 602 and to the lower external center tapped secondary winding. Node CT 20 connects to the external winding center tap. Node CT 0 is also the return line and it connects to Q 604 pin 2 , and capacitors C 603 , C 604 , C 605 , C 606 , and C 607 . The cathode of each of diodes D 602 and D 603 is connected to resistor R 607 . R 607 is then connected to the pin 1 (input) node of voltage regulator Q 604 . Voltage regulator Q 604 Pin 3 is the 18 vdc regulated DC output and is connected to the anode of blocking diode D 601 . Capacitors C 603 , C 605 , C 606 are solid dielectric type and are used to filter high frequency ripple and to prevent Q 604 from oscillating. The junction of C 603 , C 604 and D 601 cathode is the output node CP 1 +. Isolated 18-volt DC is available between nodes CT 20 and CP 2 +. To be used for regulator circuits and output switch drive during normal operation.
FIG. 28 is the main switch over temperature protection sub-circuit OTP. The sub-circuit OTP comprises thermal switch and resistors R 711 and R 712 .
Gate drive power is applied to input node GAP and to thermal switch THS 1 . Maximum FET gate voltage requires the input power voltage be less than 20 volts, the voltage selected was 18 volts. The other side of THS 1 is connected to parallel resistors [R 711 ∥R 712 ]. A single resistor may represent the resistors. The figure depicts the surface mount arrangement. The other side of [R 711 ∥R 712 ] connects to output node TS+. Normally closed thermal switch TS 1 is in contact with main switch transistor Q 1 . In the event of temperature greater than 105C THS 1 opens, thus removing power to the buffer sub-circuit AMP 1 ( FIG. 29 ) causing switch Q 1 to default to a blocking state protecting the boost switch should the optional cooling fan fail or the circuit reach high temperatures. In this instant invention the speed up buffer AMP ( FIG. 29 ) non-saturating magnetics ( FIGS. 18 , 18 A and 19 ) allows the main switch and to run cooler than prior art for a given power level. When switch temperature returns to normal range THS 1 will close, allowing the PFC to resume normal operation. Under normal load and ambient temperatures the thermal switch THS 1 should never open.
FIG. 29 PFC Buffer Circuit sub-circuit AMP, AMP 1 , AMP 2 , AMP 3 switch drive command from PFCLK ( FIGS. 23 and 24 ) or PWFM ( FIG. 33 ) control elements are connected to a gate buffer circuit. The sub-circuit AMP is comprised of power FET Q 702 , Darlington pair Q 703 , capacitors C 709 and C 715 , and resistors R 710 and R 725 .
DC Power is applied to node GA+ to transistor Q 702 drain and to capacitor C 709 , which goes to ground. Maximum gate voltage requires the input power voltage must be less than 20 volts, 18-volts was selected. Input node GA 1 is connected to the gate of FET Q 702 is connected to the base of BJT 1 of the Darlington pair Q 703 and to capacitor C 715 . C 715 is connected across the Darlington pair from the base, pin 1 , to the collectors, pins 2 and 4 , Q 703 collector node is also connected to ground. The emitter of BJT 2 is connected to the gate of FET Q 1 . The source of FET Q 702 is connected through small optional series resistor R 710 to the gate of the output switch or node GA 2 . Some power FETs under certain load may tend to oscillate when driven from a low impedance source such as this buffer. A small resistance of approximately 2 ohms or less may be required with out significant slowing of the switch. In most cases R 710 is replaced with a zero ohm jumper. Resistor R 725 is connected from node GA 0 and source of Q 702 . The input switching signal to node GAP is in range of 20 kHz to 600 kHz. Very fast “on” times are realized by proving a low impedance to rapidly charge the output switch gate connected to node GA 2 . Capacitor C 709 provides additional current when Q 702 switches on. Transistor Q 703 provides low impedance to rapidly remove the charge from the gate greatly reducing the “off” time. This particular topology provides output switch rise times on the order of 10 ns, as compared to the industry standard rise time of 250 ns. The corresponding fall time is <10 nS, again as compared to an industry fall time of 200-300 ns (See FIGS. 13 and 14 ). In the event the converter is operated at very high ambient temperatures a thermal switch may be placed in series with input power pin GA+. This allows the switch transistor to be gracefully disabled. Sub-circuit AMP greatly reduces switching losses allowing converter operation in some cases with out the common prior art forced air-cooling.
›ADDITIONAL EMBODIMENTS · 16 of 30
FIG. 30 is a schematic diagram of a snubber sub-circuit of the invention. The snubber sub-circuit SN is comprised of diodes D 804 and D 805 and resistors R 800 , R 817 , R 818 , and capacitors C 814 and C 819 .
Node SNL 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. Input node SNL 2 connects to R 800 in series with capacitor C 819 to node SNOUT. Diode D 805 anode is connected to node SNL 2 with resistors [R 817 ∥R 818 ] in parallel with D 805 . Resistors R 817 and R 818 may be combined to a single resistor. The cathode of D 805 is connected to capacitor C 814 that connects to node/pin SNL 1 . Node SNL 1 connects to the supply side of external load magnetic element. The other leg of external magnetic element is connected to the anode of D 805 and the anode side of external flyback diode D 4 . The one MEG ohm resistors R 817 and R 818 bleed the charge from C 814 resetting it for the next cycle. Capacitor C 819 and resistor R 800 captures the high frequency event from the transition of external flyback diode D 4 and moves part of the energy into the external holdup capacitor connected to node SNOUT. Since external flyback diode D 4 and D 805 isolate the drain of the output switch, faster switching occurs because the output switch does not have to slew the extra capacitance of a typical drain/source connected snubber circuit. Note that this circuit does not attempt to absorb the flyback in large RC networks that convert useful energy to losses. Nor does it attempt to stuff the flyback to ground, adding capacitance and slowing the output switch and increasing switching losses. This sub-circuit is used with it's mirror SNB ( FIG. 32 ) across the external push-pull switches. This design returns the some of the flyback energy back to the input supply or output load. The “snubbering” action slows the rise of the flyback giving time for the external flyback diode to start conduction. The circuit efficiently manages high frequency flyback pulses.
FIG. 30A is a schematic diagram of a diode snubber sub-circuit of the invention. The snubber sub-circuit DSN is comprised of diodes D 51 , D 52 , D 53 , D 54 and D 55 and capacitors C 51 , C 52 , C 53 , C 54 and C 55 .
Pin SNL 2 is connected to the anode of D 51 the cathode of D 51 is connected to the anode of D 52 the cathode of D 52 is connected to the anode of D 53 the cathode of D 53 is connected to the anode of D 54 the cathode of D 54 is connected to the anode of D 55 the cathode of D 55 is connected to pin SNOUT. Capacitors are connected across each diode forming a series parallel combination of [D 51 ∥C 51 ]+[D 52 ∥C 52 ]+[D 53 ∥C 53 ]+[D 54 ∥C 54 ]+[D 55 ∥C 55 ]. Node SNL 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. The external fly-back rectifier diode D 4 ( FIGS. 1 , 3 and 4 ) anode is connected to node SNL 2 . Node SNOUT connects to the storage capacitors [C 16 ∥C 17 ] ( FIGS. 1 , 3 and 4 ) and to the cathode of the flyback diode D 4 . External diode D 4 in parallel with DSN forms a hybrid diode. The Schottky diode has the desirable characteristics of fast recovery time (less than 6 nanoseconds (6*10 ^−9)) and low forward voltage drop (0.4-0.9 Volts) at high currents. The Schottky diode suffers from limited reverse blocking voltage currently 100 V maximum. Each diode will block 100V; the parallel capacitors distribute the reverse voltage equally across the diode string. As the reverse junction capacitance of each diode is less than 10 pf much smaller than the parallel capacitor. Thus the reverse voltage is nearly equally divided across the diodes. To guarantee even voltage division 5% or better capacitor matching is required. High precision is common and inexpensive for small capacitors. Different blocking voltages may be achieved by adjusting the number of diode/capacitor pairs. By way of example not as a limitation 500V was selected. The main fly-back rectifier diode D 4 will block high voltages but suffers from long reverse recovery time 50-500 nanoseconds is common in fast recovery diodes. What is needed is a diode with low voltage drop, high blocking voltage and very short recovery time. The snubber DSN in parallel with the main fly-back rectifier comes very close to that ideal diode. The total blocking voltage is achieved by the adding the individual diode blocking voltages. The recovery time is determined by the slowest diode in the string often less than 5 nanoseconds. The low forward voltage drop is achieved when the slower main rectifier begins conduction. Low capacitance is also realized, as the capacitance is ⅕ of the individual capacitors. This hybrid diode begins rectification immediately after the main switch stops conduction and the non-saturating magnetic begins releasing its energy. This effectively limits the high voltage flyback over shoot to less than 40-70 volts. This keeps the switch well inside it's safe operating area (SOA) allowing the switch to be run at higher voltages for higher output power and additional efficiency gain, or to use a less expensive lower voltage switch while keeping the same voltage margins. Since external flyback diode D 4 and D 805 isolate the drain of output switch, faster switching occurs because the output switch does not have to slew the extra capacitance of the typical snubber circuit. Note that this circuit does not attempt to absorb the flyback in large RC networks that generate additional heat. Nor does it attempt to stuff the flyback to ground, adding capacitance and slowing the output switch, increasing switching losses. Sub-circuit DSN may be used in parallel with any slower rectifier such as flyback diode D 4 to assist the main rectifier. This providing additional protection to the switch and rectifying the portion of the flyback pulse before the main rectifier begins condition. That high frequency energy ends up as heat or radiated noise.
FIG. 30B is a schematic diagram of an alternate snubber sub-circuit SNBB of the invention. The snubber sub-circuit SNBB is comprised of resistor R 310 and capacitor C 821 .
›ADDITIONAL EMBODIMENTS · 17 of 30
Node SNL 2 connects through capacitor C 821 to resistor R 821 to node SNOUT. Node SNOUT connects to the cathode of the flyback diode. Node SNL 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. The “snubbering” action slows the rise of the flyback giving time for the external rectifier diode(s) to begin conduction.
FIG. 31 is a schematic diagram of a snubber sub-circuit of the invention. The snubber sub-circuit SNA is comprised of resistor R 810 and R 811 and capacitors C 820 and C 821 .
Node SNA 1 connects to series resistor R 810 to capacitor C 820 to node SNA 2 then to capacitor C 821 and series resistor R 811 to node SNA 3 . Node SNA 1 connects to the external magnetic element center tap. Node SNA 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. Node SNA 3 connects to the source terminal of the external output switch. Resistor R 810 and C 820 attempt to absorb part of the flyback to reduce voltage transients across the switch. Part of the flyback is returned to ground by C 821 . This sub-circuit is used with its mirror SNA ( FIG. 31 ) across the external push-pull switches. The “snubbering” action slows the rise of the flyback giving time for the external rectifier diodes D 80 and D 90 of FIG. 25 or 25 A to start conduction. The circuit efficiently manages high frequency flyback pulses.
FIG. 32 is a schematic diagram of a snubber sub-circuit of the invention. The snubber sub-circuit SNB comprises resistor R 820 and R 821 and capacitors C 840 and C 841 .
Node SNB 1 connects to series resistor R 820 to capacitor C 820 to node SNA 2 to capacitor C 841 and to series resistor R 821 to node SNB 3 . Node SNB 1 connects to the external magnetic element center tap. Node SNB 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. Node SNB 3 connects to the source terminal of the external output switch. Resistor R 820 and C 840 attempt to absorb part of the high frequency flyback to reduce voltage transients across the switch. C 841 and R 821 return part of the flyback to ground. The “snubbering” action slows the rise of the flyback giving time for the external rectifier diodes D 80 and D 90 of FIG. 25 or 25 A to start conduction. The circuit efficiently manages high frequency flyback pulses.
FIG. 33 is the inventions PWM (pulse width modulator) and FM (frequency modulator) sub-circuit. Sub-circuit PWFM consists of resistors R 401 , R 402 , R 403 , and R 404 capacitors C 401 , C 402 , C 403 , C 404 , C 405 and C 406 , controller IC U 400 and diode D 401 .
Control element U 400 connects to a circuit with the following series connections: from pin 1 to feedback pin PW 1 then to the wiper of adjustable resistor R 404 to return node PWFM 0 . Resistor R 404 may be replaced with two fixed resistors. Capacitor C 403 is connected from pin 2 to pin 1 . Capacitor C 403 is used to filter the error amp output. The upper half of resistor R 404 is connected to node REF 1 pin 8 the 5.0-Volt internal reference. Internal 5.0-volt reference U 400 pin 8 or Node REF 1 is connected to the upper half of resistor R 403 and through capacitor C 402 to return node PWFM 0 . The reference provides current to external feed back networks. Wiper of R 403 connects to node FM 1 to pin 4 , through R 402 to pin 3 , and through C 404 to return node PWFM 0 . Resistor R 403 may be replaced with two fixed resistors. Pulse width timing capacitor C 404 connects pin 3 to return node PWFM 0 . Low leakage diode D 401 anode is connected to pin 3 cathode to output pin 6 node CLK. Resistor R 404 sets the nominal pulse width of output pin 6 node CLK. The pulse width can be adjusted from 0 (off) to 95%. Resistor R 403 and C 404 determine the nominal operating frequency. With application of power 20-volts between Nodes PWFM+ and PWFM 0 controller U 400 generates an internal 5.0 reference voltage to pin 7 node REF 1 . Output pin 6 node CLK is set high approximately 20-volts (see oscillograph trace G 6 segment 60 FIG. 34 ). C 404 starts to charge through R 401 until the voltage across C 404 at pin 3 reaches the comparator level (see oscillograph trace G 1 segment 61 FIG. 34 ) at resetting the pin 6 low (see oscillograph trace G 6 segment 62 FIG. 34 ). Capacitor C 404 rapidly discharges though D 401 (see oscillograph trace G 1 segment 63 FIG. 34 ). Pin 3 remains 0.6-volts above PWFM 0 node during the period pin 6 is low (see oscillograph trace G 1 segment 64 FIG. 34 ). On the rising edge of pin 6 capacitor C 405 begins to rapidly charge until the voltage in pin 4 reaches the internal comparator level (see oscillograph trace G 4 segment 65 FIG. 34 ). The comparator triggers internal transistor to rapidly discharge C 404 (see oscillograph trace G 4 segment 66 FIG. 34 ). The cycle repeats with output pin 6 being set high. External feedback current applied to U 400 pin 1 and node PW 1 (see oscillograph trace Gl segment FIG. 34 ) follows the actual output voltage. Oscillograph trace G 1 segment 67 ( FIG. 34 ) is the period when the output switch conducting storing energy in the NSME. Oscillograph trace G 1 segment 68 ( FIG. 34 ) is the period when the output switch is off allowing storing energy in the NSME to be transferred to the storage capacitor. Application of external current source or feed back network to pin 1 or node PW 1 allows the pulse width to be modulated. Removing current from PW 1 lowers the comparator level causing the comparator to trigger at lower voltages across C 404 reducing the pulse width. Introducing current into node PW 1 increases pulse width from nominal to maximum of 95%. Resistor R 404 and C 404 determine the nominal pulse width. This design allows the CLK output to be pulse width modulated. Application of external feed back network to pin 4 or node FW 1 allows the frequency to be modulated. Removing current from FW 1 slows the charging of C 405 . Longer charging time lowers the frequency from the nominal setting. This arrangement allows the CLK output to frequency modulated. When used with a resonant controller, R 403 and C 405 determine the nominal frequency typically equal to the tank resonant frequency. The external feedback is configured to lower the frequency from nominal (maximum output) to zero frequency “off”. When used as a pulse-width controller the nominal is set to maximum pulse width of about 90% feedback reduces the pulse-width. Sub-circuit PWFM may be simultaneously frequency and pulse width modulated. This configuration and mode of operation is unique to this instant invention. Feeding back of the output to the error amplifier is a unique mode of operation for control element U 400 . Sub-circuit PWFM combines large dynamic range, precise control and fast response.
›ADDITIONAL EMBODIMENTS · 18 of 30
FIG. 34 Oscillograph traces of the PWFM ( FIG. 33 ) controller in the pulse-width modulation mode.
FIG. 35 Oscillograph trace of the TCTP ( FIG. 8 ) resonant converter primary voltage. FIG. 35 is an oscillograph trace of the voltage developed across capacitor C 10 (FIG. 8 ). In this embodiment the supply VBAT was only 18-volts.
The primary 100 ( FIG. 18 ) inductance 203 uH was achieved by 55 turns on a 26 u 2.28 oz. KoolMu magnetic element 101 . The secondary winding 103 ( FIG. 18 ) is 15 turns on core 101 . A 5.5-watt load is connected to winding 103 . The NSME primary 100 ( FIG. 18 ) developed an excitation voltage of 229 volts peak more than 10 times VBAT. Tank converters TCTP and TCSSC ( FIG. 7 ) take advantage of the desirable properties of the non-saturating magnetic to develop large flux biases. The useful large flux may harvested into useful power by addition of “flux nets” windings to the magnetic element.
FIG. 36 Regulated 18_Volt DC control power sub-circuit REG. Sub-circuit REG consists of resistor R 517 , regulator Q 514 and capacitors C 514 , C 515 , C 516 , C 518 , and C 517 .
Pin REG 0 connects to the external power source return. Node REG 0 is also the return line it connects to Q 514 pin 2 , and capacitors C 518 , C 514 , C 515 , and C 517 . Resistor R 517 is connected to the pin 1 (input) node of voltage regulator Q 514 and to input pin RIN+. Voltage regulator Q 514 Pin 3 is the 18 vdc regulated DC output is connected to the capacitors C 515 , C 514 and output pin 18V. Capacitors C 515 , C 517 are solid dielectric type is used to filter high frequency ripple and to prevent Q 514 from oscillating. Sub-circuit REG provides regulated power for control circuits and output switch buffer AMP (FIG. 29 ).
FIG. 37 is a schematic for a non-isolated high side switch buck converter sub-circuit HSBK. FIG. 37 is a non-isolated high side switch buck converter sub-circuit HSBK. This converter topology consists of a non-isolated high efficiency buck stage, which provides regulated power to an efficient push-pull isolation stage. Sub-circuit HSBK consists of diode D 8 , capacitor C 8 , FET transistor Q 31 , sub-circuit TCTP (FIG. 8 ), sub-circuit BL 1 (FIG. 18 B), sub-circuit IFB (FIG. 40 B), sub-circuit AMP ( FIG. 29 ) and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. Pin DCIN+ connects to transistor Q 31 source, sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , and sub-circuit IFB pin FBE, sub-circuit TCTP pins DCIN+ and B−. Regulated 18-volt output from sub-circuit TCTP pin B+ connects to sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. This provides the positive gate drive relative to the source of Q 31 . Power source VBAT return is connected to pin DCIN−, sub-circuit TCTP pin DCIN−, diode D 68 anode, capacitor C 68 , RLOAD, sub-circuit IFB pin OUT−, output pin B− and ground/return node GND. Sub-circuit PWFM is designed for adjustable pulse-width operation from 0 to 90%, maximum pulse width occurs with no feedback current to pin PW 1 . Increasing the feedback current reduces the pulse-width and output voltage from converter HSBK. Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP. The output of sub-circuit AMP pin GA 2 is connected to the gate of Q 31 . The drain of Q 31 is connected to sub-circuit BL 1 pin P 1 B and the cathode of D 68 . Pin P 1 A of sub-circuit BL 1 is connected to capacitor C 8 , sub-circuit IFB pin OUT− and RLOAD. With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 31 . Switch Q 31 conducts charging capacitor C 68 through NSME BL 1 from source VBAT and storing energy in BL 1 . Feedback output pin FBC from sub-circuit IFB is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . As the output voltage reaches the designed level sub-circuit IFB removes current from PW 1 commanding PWFM to reduce the pulse-width or on time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PWFM switches output pin CLK low turning off Q 31 stopping the current into BL 1 . The stored energy is released from NSME BL 1 into the now forward biased diode D 68 charging capacitor C 68 . By modulating the on time of switch Q 31 the converter “bucks” applied voltage and efficiently regulates to a lower voltage. Regulated voltage is developed across Nodes B− and B+. Sub-circuit IFB provides the isolated feedback voltage to the sub-circuit PWFM. When sub-circuit IFB senses the converter output (nodes B+ and B−) is at the designed voltage more current is conducted by the phototransistor. Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus reducing the converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 31 is removed stopping all buck activity capacitor C 68 discharges through RLOAD. Input current from VBAT is sinusoidal making the converter very quiet. As such the switch Q 31 is not exposed to large current spikes common to saturating magnetic prior art. Thus placing less stress on the switches thereby increasing the MTBF. Sub-circuit HSBK takes advantage of the desirable properties of the NSME in this converter topology.
FIG. 38 is a schematic for an isolated two-stage low side switch buck converter sub-circuit LSBKPP. This converter topology consists of a high efficiency low-side switch buck stage, which provides regulated power to an efficient push-pull isolation stage. An efficient center-tap fullwave rectifier provides rectification. Sub-circuit LSBKPP consists of diode D 46 , capacitor C 46 , FET transistor Q 141 , sub-circuit REG (FIG. 36 ), sub-circuit OUTB (FIG. 25 A), sub-circuit BL 1 (FIG. 18 B), sub-circuit TCTP (FIG. 8 ), sub-circuit IFB (FIG. 40 B), sub-circuit AMP (FIG. 29 ), sub-circuit DCAC 1 , and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. From pin DCIN+ connects to sub-circuit REG pin RIN+, D 46 cathode, capacitor C 46 , sub-circuit TCTP ( FIG. 8 ) pin DCIN+, and sub-circuit DCAC 1 pin DC+. Voltage regulator sub-circuit REG output pin +18V connects to sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit REG provides regulated low voltage power to the controller and to the main switch buffer. VBAT negative is connected to pin DCIN− and ground return node GND. Node GND connects to sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , Q 141 source, sub-circuit IFB pin FBE, sub-circuit REG pin REG 0 and sub-circuit TCTP pin DCIN−. Sub-circuit PWFM ( FIG. 33 ) is designed for variable pulse width operation. The nominal frequency is between 20-600 Khz PWFM is configured for maximum pulse width 90% (maximum buck voltage) with no feedback current from sub-circuit IFB. Increasing the feedback current reduces the Q 141 on time reducing the voltage to the push-pull stage and the output from converter LSBKPP. Sub-circuit PWFM clock output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP (FIG. 29 ). The output of switch speed up buffer sub-circuit AMP pin GA 2 is connected to the gate of Q 141 . Floating isolated 18-volt power from sub-circuit TCTP pin B+ connects to sub-circuit DCAC 1 pin P 18 V. The drain of Q 141 is connected to sub-circuit BL 1 pin P 1 A and the anode of D 46 . The return line of sub-circuit DCAC 1 pin DC− connects to sub-circuit BL 1 pin P 1 B, sub-circuit TCTP pin B− and C 46 . With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 141 . Switch Q 141 conducts reverse biasing diode D 46 ; capacitor C 46 starts charging through NSME BL 1 from source VBAT. During the time Q 141 is conducting, energy is stored in NSME sub-circuit BL 1 . Charging C 46 provides power to final push-pull converter stage DCAC 1 . The output of the output rectifier sub-circuit OUTB is connected to feedback sub-circuit IFB output pin FBC from sub-circuit IFB is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . Sub-circuit IFB removes current from PW 1 commanding PWFM to reduce the pulse-width or on time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PFFM switches CLK low turning off Q 141 stopping the current into BL 1 . The energy is released from NSME BL 1 into the now forward biased flyback diode D 46 charging capacitor C 46 . By modulating the on time of switch Q 141 the converter voltage is regulated. Regulated voltage is developed across C 46 Nodes DC+ and GND. Providing energy to the isolated constant frequency push-pull DC to AC converter sub-circuit DCAC 1 (FIG. 2 ). Sub-circuit DCAC 1 provides efficient conversion of the regulated buck voltage to a higher or lower voltage set by the magnetic element winding sub-circuit PPT 1 ( FIG. 19 ) ratio. The center tap of the push-pull output magnetic is connected to, sub-circuit OUTB pin OUT−, RLOAD, sub-circuit IFB pin OUT− and the pin OUT− forming the return line for the load and feedback network. Output of sub-circuit DCAC 1 pin ACH is connected to sub-circuit OUTB pin C 7 B. Output of sub-circuit DCAC 1 pin ACL is connected to sub-circuit OUTB pin C 8 B. Sub-circuit OUTB provides rectification of the AC power generated by sub-circuit DCAC 1 . As the non-saturation magnetic converter is very quite minimal filtering is required by OUTB. This further reduces cost and improves efficiency as losses to filter components are minimized. Sub-circuit IFB provides the isolated feedback current to the sub-circuit PWFM. When sub-circuit IFB senses the converter output (nodes OUT+ and OUT−) is greater than the designed/desired voltage, current is removed from node PW 1 . Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus increasing the buck action and reducing the first stage converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 141 is removed stopping all buck activity capacitor discharging C 46 . Input current from VBAT to charge C 46 is sinusoidal making the converter very quiet. In addition the switch Q 141 is not exposed a potentially destructive current spike. Placing less stress on the switches thereby increasing the MTBF. Sub-circuit LSBKPP takes advantage of the desirable properties of the NSME in this converter topology. Adjusting the NSME BL 1 ( FIG. 18B ) sets the amount of buck voltage available to the final push-pull isolation stage. Greater efficiencies are achieved at higher voltages. The final output voltage is set by the turns ratio of the push-pull element PPT 1 (FIG. 19 ). Converter LSBKPP provides efficient conversion from high voltage sources into high current isolated output.
›ADDITIONAL EMBODIMENTS · 19 of 30
FIG. 39 is a schematic for an isolated two-stage low side switch buck converter sub-circuit LSBKPPBR. This converter topology consists of a non-isolated high efficiency low-side switch buck stage, which provides regulated power to an efficient push-pull isolation stage. A fullwave bridge rectifier provides rectification. Sub-circuit LSBKPPBR consists of diode D 6 , capacitor C 6 , FET transistor Q 11 l, sub-circuit REG (FIG. 36 ), sub-circuit OUTBB (FIG. 25 B), sub-circuit BL 1 (FIG. 18 B), sub-circuit TCTP (FIG. 8 ), sub-circuit IFB (FIG. 40 B), sub-circuit AMP (FIG. 29 ), sub-circuit DCAC 1 (FIG. 2 ), and sub-circuit PWFM (FIG. 33 ).
External power source VBAT connects to pins DCIN+ and DCIN−. From pin DCIN+ connects to sub-circuit REG pin RIN+, D 6 cathode, capacitor C 6 , sub-circuit TCTP ( FIG. 8 ) pin DCIN+, and sub-circuit DCAC 1 pin DC+. Voltage regulator sub-circuit REG output pin +18V connects to sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit REG provides regulated low voltage power to the controller and to the main switch buffer. VBAT negative is connected to pin DCIN− connects to sub-circuit PWFM pin PWFM 0 , sub-circuit AMP pin GA 0 , Q 111 source, sub-circuit IFB pin FBE, sub-circuit REG pin REG 0 , sub-circuit TCTP pin DCIN−. Sub-circuit PWFM ( FIG. 33 ) is designed for variable pulse width operation. The nominal frequency is between 20-600 Khz PWFM is configured for maximum pulse width 90% (maximum buck voltage) with no feedback current from sub-circuit IFB. Increasing the feedback current reduces the Q 111 on time reducing the voltage to the push-pull stage and the output from converter LSBKPPBR. Sub-circuit PWFM clock output pin CLK is connected to the input pin GA 1 of buffer sub-circuit AMP (FIG. 29 ). The output of switch speed up buffer sub-circuit AMP pin GA 2 is connected to the gate of Q 111 . Floating isolated 18-volt power from sub-circuit TCTP pin B+ connects to sub-circuit DCAC 1 pin P 18 V. The drain of Q 111 is connected to sub-circuit BL 1 pin PA 1 and the anode of D 6 . The return line of sub-circuit DCAC 1 pin DC− connects to sub-circuit BL 1 pin P 1 B, sub-circuit TCTP pin B− and C 6 . With sub-circuit PWFM pin CLK high buffer AMP output pin GA 2 charges the gate of transistor switch Q 111 . Switch Q 111 conducts reverse biasing diode D 6 ; capacitor C 6 starts charging through NSME BL 1 from source VBAT. During the time Q 111 is conducting, energy is stored in NSME sub-circuit BL 1 . Charging C 6 provides power to final push-pull converter stage DCAC 1 . The output of the output rectifier sub-circuit OUTBB is connected to feedback sub-circuit IPB output pin FBC from sub-circuit IFB is connected to sub-circuit PWFM pulse-width adjustment pin PW 1 . Sub-circuit IFB removes current from PW 1 commanding PWFM to reduce the pulse-width or on time of signal CLK. After sub-circuit PWFM reaches the commanded pulse-width PFFM switches CLK low turning off Q 111 stopping the current into BL 1 . The energy is released from NSME BL 1 into the now forward biased flyback diode D 6 charging capacitor C 6 . By modulating the on time of switch Q 111 the converter voltage is regulated. Regulated voltage is developed across C 6 nodes DC+ and DC−. Providing energy to the isolated constant frequency push-pull DC to AC converter sub-circuit DCAC 1 (FIG. 2 ). Sub-circuit DCAC 1 provides efficient conversion of the regulated buck voltage to a higher or lower voltage set by the magnetic element winding sub-circuit PPT 1 ( FIG. 19 ) ratio. The return node of the sub-circuit OUTBB pin OUT− is connected to RLOAD, sub-circuit DCAC 1 pin ACO, sub-circuit IFB pin OUT− and the pin OUT−. Node OUT− is the return line for the load and feedback network. Output of sub-circuit DCAC 1 pin ACH is connected to sub-circuit OUTBB pin C 7 B. Output of sub-circuit DCAC 1 pin ACL is connected to sub-circuit OUTBB pin C 8 B. Sub-circuit OUTBB provides rectification of the AC power generated by sub-circuit DCAC 1 . As the disclosed non-saturation magnetic converter has minimal output ripple, less filtering is required by OUTBB. This further reduces cost and improves efficiency as losses in filter components are minimized. Sub-circuit IFB provides the isolated feedback current to the sub-circuit PWFM. Open collector output of IFB pin FBC connects to PWFM pin PW 1 . When sub-circuit IFB senses the converter output (nodes OUT+ and OUT−) is greater than the designed/desired voltage, current is removed from node PW 1 . Sinking current from PW 1 commands the PWFM to a shorter pulse-width thus increasing the buck action and reducing the first stage converter output voltage. In the event the feedback signal from IFB commands the PWFM to minimum output. Gate drive to switch Q 111 is removed stopping all buck activity capacitor discharging C 6 . As the NSME does not saturate the destructive noisy current spikes common to prior art are absent. Input current from VBAT to charge C 6 is sinusoidal making the converter very quiet. In addition the switch Q 111 is not exposed a potentially destructive current spike. Placing less stress on the switches thereby increasing the MTBF. Sub-circuit LSBKPPBR takes advantage of the desirable properties of the NSME in this converter topology. Adjusting the NSME BL 1 ( FIG. 18B ) sets the amount of buck voltage available to the final push-pull isolation stage. Greater efficiencies are achieved at higher voltages. The final output voltage is set by the turns ratio of the push-pull element PPT 1 (FIG. 19 ). Converter LSBKPPBR provides efficient conversion from high voltage sources such as high power factor AC to DC converters such as sub-circuit ACDCPF (FIG. 4 ).
FIG. 40 is the schematic of the inventions isolated over voltage feed back network sub-circuit IPFFB. Sub-circuit IPFFB consists of Resistors R 926 , R 927 , R 928 , R 929 and R 930 , capacitor C 927 , zener diodes D 928 and D 903 , transistor Q 915 and opto-isolator U 903 .
Node PF+ connects through resistor R 927 to cathode of D 903 and anode of opto-isolator U 903 . Cathode of diode D 903 is connected to pin PF+. Resistor R 928 is connected from anode of D 928 to base of Q 915 . Capacitor C 927 is connected in parallel with zener diode D 903 . Resistor R 928 limits maximum base current. Resistor R 929 is connected between base and emitter of Q 915 . Resistor R 929 is used to shunt excess zener leakage current from the base common in high voltage diodes. Two hundred-volt zener diode cathodes D 928 are connected to pin PF+. Anode of D 928 is connected to R 930 and R 928 . Resistor R 930 provides a path for leakage current from 200-volt zener D 928 . Resistor R 926 limits the maximum current to U 903 internal light emitting diode to about 10 ma. Resistor R 927 sets the maximum zener current at maximum boost voltage of approximately 200-volts to 20 ma. Transistor Q 915 is biased off when the voltage from node PF+ and PF− is less than the zener voltage of 200-volts. Transistor is in a cutoff or non-conducting state no current is injected to U 903 LED. The internal phototransistor is also in a non-conducting state. The attached external control sub-circuit is not commanded to change its output. With 200 volts or more applied to nodes PF+ and PF− reverse biased zener diode D 928 injects current into the base of Q 915 . Resistor R 927 , capacitor C 927 and diode D 903 provide 18-volts to the collector of Q 915 . Transistor Q 915 conducts current into U 903 LED injecting base current into the U 903 phototransistor. Modulating the LED current is reflected as variable impedance between FBC and FBE. This phototransistor may be connected as a variable current source or impedance. This sub-circuit senses excessive boost voltage and quickly feeds back to the control sub-circuit (See PFA (FIG. 23 ), PFB ( FIG. 24 ) or (PWFM FIG. 33 ) automatically reducing the boost voltage.
›ADDITIONAL EMBODIMENTS · 20 of 30
FIG. 40A is a schematic diagram of the non-isolated boost output voltage feed back sub-circuit FBA. Sub-circuit FBA consists of Resistors R 1120 , R 1121 , R 1122 , R 1123 and R 1124 .
Input node PF+ connected to series resistor [R 1123 +R 1124 ] then to parallel resistors [R 20 ∥R 21 ∥R 22 ] to the return node BR−. Resistors R 1120 , R 1121 , R 1122 , R 1123 and R 1124 values are selected for a nominal input voltage of 385-volts and output feed back voltage of 3.85. (See oscillograph G 1 FIG. 34 ) Resistors R 1120 , R 1121 , R 1122 , R 1123 and R 1124 are shown in surface mount configuration but can be combined into two thru hole-resistors. Feedback output node PF 1 is connected to node PF 1 of sub-circuit PFA ( FIG. 23 ) or PFB (FIG. 24 ). Return pin BR− is connected to BR− of PFA ( FIG. 23 ) or PFB (FIG. 24 ). Nodes FBE and FBC it may also be connected between nodes FM 1 pin PWFM 0 or PW 1 pin PWFM 0 of control sub-circuit PWFM (FIG. 33 ).
FIG. 40B is the schematic of the inventions isolated low voltage feed back network sub-circuit FBA. Sub-circuit IFB consists of Resistors R 900 , R 901 and R 902 , zener diode D 900 , Darlington transistor Q 900 and opto-isolator U 900 .
Node OUT+ connects cathode of D 900 to R 901 . Anode of diode D 900 is connected to series resistor R 900 to base of Darlington transistor Q 900 . Resistor R 902 is connected from base to emitter to Q 900 . Resistor R 901 connects to anode of opto-isolator U 900 LED (light emitting diode) the cathode is connected to Q 900 collector. Emitter of Q 900 is the return current path and connects to pin/node OUT−. Resistor R 901 limits the maximum current to U 900 internal light emitting diode to 20 ma. Resistor R 902 shunts some of the zener leakage current from the base. Zener diode voltage selection sets the converter output voltage a typical value maybe 48-volts. The zener voltage is the final desired output minus two base emitter junction drops (1.4V). Once the OUT+ node reaches the zener voltage a small base current biases Q 900 into a conducting state turning “on” opto-isolator U 900 internal LED. Resistor R 900 limits the maximum base current to Q 900 . Resistors R 900 and R 901 are selected to bias Darlington transistor Q 900 collector current with nominal voltage across nodes OUT+ and OUT−. Change in voltage between OUT+ and OUT− modulates the opto-isolator U 900 LED current in turn changing the base current of U 900 internal photo transistor. Phototransistor emitter is node FBE collector is node FBC. Modulating the LED current is reflected as variable impedance between FBC and FBE. This phototransistor may be connected as a variable current source or impedance. When used with control sub-circuit PFA (FIG. 23 ), PFB ( FIG. 24 ) or (PWFM FIG. 33 ) the phototransistor is connected as a current shunt. Higher voltage applied to OUT+ and OUT− nodes increases the feedback shunt current commanding the control sub-circuit (See PFA ( FIG. 23 ) or PFB ( FIG. 24 ) or PWFM ( FIG. 33 ) to reduce the pulse-width or frequency. IFB accomplishes high speed feed back due to the very high gain of the Darlington transistor and the rapid response of the internal converter stage(s) active ripple reduction and excellent load regulation are achieved.
FIG. 40C is the schematic of the alternate PFC isolated over voltage feed back network sub-circuit IOVFB. Sub-circuit IOVFB consists of resistors of R 917 , R 938 , R 939 and R 940 , diode D 911 , Darlington transistor Q 914 and opto-isolator U 905 .
The output of the PFC at pin PF+ is connected to R 917 then to collector of Q 914 . Resistor R 917 sets the maximum current to U 905 light emitting diode. Resistor R 938 is connected from return node PF+ to zener diode D 911 cathode and R 938 . Resistor R 939 is connected from return node PF− to zener diode D 911 cathode and R 938 . Anode of D 911 is connected to wiper arm of adjustable resistor R 940 . One leg of R 940 is connected to the base of transistor Q 914 the other to R 939 and U 905 LED anode and R 939 . Emitter of Q 914 is connected to anode of U 904 . Adjustable resistor R 940 sets the maximum or trip voltage before transistor Q 914 is biased on. Providing current to U 905 LED. Phototransistor emitter is node FBE collector is node FBC. Modulating the LED current is reflected as variable impedance between FBC and FBE. This phototransistor is normally connected as a shunt to force the control element to a minimum output. This sub-circuit senses the boost voltage and feeds back to the PFC. Where excessive boost voltage forces the PFC to automatically reduce the boost voltage.
FIG. 40D is a schematic diagram of and alternate for the non-isolated boost output voltage feed back sub-circuit FBD Sub-circuit FBD consists of Resistors R 1120 , R 1121 , R 1122 , R 1123 and R 1124 .
Input node PF+ connected to series resistor [R 1123 +R 1124 ] then to parallel resistors [R 1122 ∥R 1121 ]. The other side of [R 1122 ∥R 1121 ] is connected to wiper arm of R 1121 and through to [R 1123 ∥R 1120 ] to the return node BR−. Resistor values are selected for a nominal input voltage of 385-volts. Resistors R 1120 -R 1124 are shown in a surface mount configuration but, can be combined into other series parallel combinations to form other equivalent circuits. Feedback output node PF 1 is connected to node PF 1 of sub-circuit PFA ( FIG. 23 ) or PFB (FIG. 24 ). Return pin BR− is connected to BR− of PFA ( FIG. 23 ) or PFB (FIG. 24 ). Nodes FBE and FBC may also be connected between nodes FM 1 pin PWFM 0 or PW 1 pin PWFM 0 of control sub-circuit PWFM (FIG. 33 ). Component values are selected to provide a 15-volt adjustment range.
FIG. 41 is the schematic of the alternate low voltage feed back network sub-circuit FBI. Sub-circuit FBI consists of Resistors R 81 , R 82 and R 83 , zener diode D 80 , NPN transistor Q 80 and capacitor C 80 .
Node OUT+ connects cathode of D 80 . Anode of diode D 80 is connected to through resistor R 83 to OUT− and resistor R 82 to base of transistor Q 80 . Capacitor C 80 is connected from base to pin OUT−. Capacitor C 80 bypasses high frequency to noise to OUT−. Resistor R 81 is connected from emitter of Q 80 to node OUT−. Resistor R 81 adds local negative feedback to reduces the effects of variation in transistor gain. Collector of Q 80 is connected to pin FBC. The return current node connects to pins FBE and OUT−. Resistor R 82 limits the maximum base current protecting Q 80 . Resistor R 83 shunts some of the zener leakage current from the base. Zener diode voltage selection sets the converter output voltage a typical value maybe 48-volts. The zener voltage is the final desired output minus one base emitter junction drop (0.65-Volts). When the OUT+ node reaches the nominal level reverse biased zener starts to conduct injecting a small base current into Q 80 . Biasing transistor into a conducting state. Change in voltage between OUT+ and OUT− modulates Q 80 collector current. During normal operation the zener diode is biased at it's knee thus small changes in voltage result in relatively large collector current changes. When sub-circuit FBI used with control sub-circuit PFA (FIG. 23 ), PFB ( FIG. 24 ) or ( FIG. 33 ) the transistor is connected as a current shunt. Higher voltage applied to OUT+ and OUT− nodes increases the feedback shunt current commanding the control sub-circuit (See PFA ( FIG. 23 ) or PFB ( FIG. 24 ) or PWFM ( FIG. 33 ) to reduce the pulse-width or frequency. Sub-circuit FBI provides high-speed feedback and gain to ripple components. With the rapid response of the internal converter stage(s) active ripple reduction and excellent load regulation are achieved.
›ADDITIONAL EMBODIMENTS · 21 of 30
FIG. 41A is the schematic of an alternate over voltage feed back network sub-circuit FB 2 . Sub-circuit FB 2 consists of Resistors R 419 , R 418 , R 414 and R 410 , zener diode D 410 , and NPN transistors Q 414 and Q 413 .
Node PF+ connects to series resistors R 410 +R 419 +R 418 then to common or ground forming voltage divider. The junction of R 418 and R 419 connects to collector of Q 414 and cathode of Zener diode D 410 . Diode D 410 anode connects to base of transistor Q 414 . Emitter of Q 414 connects to base of Q 413 and through resistor R 414 to ground. Emitter of Q 413 is also connected to ground. Collector of Q 413 connects to node PF 2 for connection to regulator sub-circuit PFB pin 2 . Resistors R 410 , R 419 , R 418 and D 410 are selected to forward bias transistors Q 413 and Q 414 when node PF+exceeds 450VDC relative to common. This regulates the boost activity until the fault condition subsides providing fast reliable alternative regulation thus meeting UL test requirements.
FIG. 42 is the schematic of the inventions over voltage protection embodiment sub-circuit OVP. Sub-circuit OVP consists of SCR (silicon controlled rectifier) SCR 1200 , resistor R 1200 , capacitor C 1200 and zener diodes D 1200 , D 1202 and D 1203 .
Input pin PF+ is connected to cathode of zener diode D 1203 , anode of D 1203 is connected to series zener diodes [D 1202 +D 1200 ] then to gate of SCR 1200 . Noise attenuation network of [R 1200 ∥C 1200 ] is connected from SCR SCR 1200 gate to the return node BR−. Diodes D 1102 and D 1103 are both 200-volt; D 1101 is a 5.1-volt type the sum of the zener voltages set the trip point of the OVP at 405-volts. Other trip voltages may be implemented by selecting other zener diode combinations. Capacitor C 1200 and R 1200 prevents leakage current and transients from accidentally tripping the OVP. In the event of very high AC line voltages or a component failure in a feed back loop ( FIGS. 40A , 40 B, 40 C or 40 ) The boost voltage may quickly rise increase to levels dangerous to the output switch or output storage capacitors. When the output boost voltage of the at node PF+ rises above 405V, zener diodes D 1203 , D 1202 and D 1200 conduct a small current into the gate of SCR 1200 turning SCR 1200 on. Turning SCR 1200 on places a low impedance path across the AC line through the rectifier sub-circuit BR (FIG. 22 ). SCR 1200 and bridge rectifier diodes must be selected to withstand the short circuit currents that may exceed 100 amperes until the input fuse opens. Thus quickly limiting the boost output voltage to a safe level. This circuit should never operate under normal AC line voltages. By changing zener voltages this sub-circuit would also be suitable for use in the across the rectifier output to protect the load from an over voltage condition. Sub-circuits OVP 1 shuts down the converter with out opening the line fuse. Sub-circuit OVP may be used in combination with OVP 1 ( FIG. 42A ) as a fail-safe back up for critical loads.
FIG. 4A is the schematic of the inventions over voltage protection embodiment sub-circuit OVP 1 . Sub-circuit OVP 1 consists of SCRs (silicon controlled rectifier) SCR 1101 and SCR 1100 , resistors R 1101 and R 1102 , capacitors C 1100 and C 1101 and zener diodes D 1100 , D 1102 and D 1103 .
Anode of SCR 1100 is node/pin CP 18 V+ that is connected to external control DC source. Return node BR− is connected to SCR 1101 cathode and capacitor C 1100 . Input node PF+ is connected to cathode of zener diode D 1103 and to series resistor R 1100 then to anode of SCR SCR 1101 . The anode of D 1103 is connected to the cathode of D 1102 . The anode of D 1102 is connected to the cathode of D 1100 . The anode of D 1100 is connected to the gate of SCR 1101 . The anode of D 1103 is connected to series zener diodes [D 1102 +D 1100 ] then to capacitor C 1100 then to the return node BR−. Capacitor [C 1200 ∥R 1200 ] prevents leakage current and transients from accidentally tripping OVPB. In the event of very high AC line voltages or a component failure in a feed back loop (IPFFB FIG. 40A , FBA FIG. 40B , IFB FIG. 40C or FBI FIG. 41 ) The boost voltage may quickly rise increase to levels dangerous to the output switch or output storage capacitors. When the output boost voltage of the at node PF+ rises above 405V, zener diodes D 1103 , D 1102 and D 1100 conduct a small current into the gate of SCR 1101 latching SCR 1101 on. Resistor R 1100 provides holding current for SCR 1101 . Turning SCR 1101 on provides gate current to SCR 1100 , resistors R 1100 and R 1101 limit gate current. With gate current to SCR 1100 the SCR is turned on providing a low impedance path from nodes CP 18 V+ to BR−. This action removes the regulated power to the main switch buffer and or PWM controllers PFA ( FIG. 23 ) or PWFM ( FIG. 33 ) and or buffer AMP ( FIG. 29 ) thus turning off the main switch. The converter is held in an off state until boost voltage PF+ through R 1100 can not maintain the holding current of SCR 1101 . Typically power must be removed from the system to reset SCR 1101 . The minimum holding current of SCR 1101 is typically 5-10 ma. The action of OVP 1 quickly limits the boost output voltage to a safe level. This circuit should never operate under normal AC line voltages. By changing zener voltages this sub-circuit would also be suitable for use across the output rectifier to protect the load from an over voltage condition. Sub-circuit OVP 1 gracefully shuts down the converter requiring manual intervention to reset the fault.
FIG. 42B is the schematic of the isolated output over voltage feed back network sub-circuit OVP 2 . Sub-circuit OVP 2 consists of resistors of R 970 , R 971 , and R 972 , capacitor C 970 , zener diode D 970 , SCR SCR 970 , Darlington transistor Q 970 and opto-isolator U 970 .
The output of the converter at pin OUT+ is connected to R 972 and to the cathode of zener diode D 970 . The anode of D 970 is connected to series resistor R 970 then to base of Q 970 and capcitor C 970 . Resistor R 970 sets the maximum base current to Q 970 . Resistor R 971 is connected between the anode of D 970 and return node OUT−. Anode of light emitting diode U 970 is connected to resistor R 972 then to OUT+. The cathode of U 970 LED is connected to Q 980 collector. Emitter of Q 980 is connected to return node OUT− and second side of capacitor C 970 . Zener diode D 960 sets the maximum or trip voltage before transistor Q 970 is biased on providing current to U 970 LED. Application of voltage greater than the zener voltage of D 970 injects a small base current into Q 970 . Transistor Q 970 turns on the internal LED of U 970 placing phototransistor in a conducting state and low impedance to pins OVC and OVE. External push-pull driver sub-circuit PPG ( FIG. 43 ) is shut down immediately by bringing pin PPEN high stopping the output stage. Sub-circuit OVP 2 senses the output voltage and quickly feeds back to the push-pull PFC. Where excessive boost voltage forces the PFC to automatically reduce the boost voltage.
›ADDITIONAL EMBODIMENTS · 22 of 30
FIG. 42C is the schematic of the isolated output over voltage crowbar network sub-circuit OVP 3 . Sub-circuit OVP 3 consists of resistors of R 980 , R 981 , R 982 , R 983 , R 984 and R 985 , capacitors C 980 , C 981 and C 982 zener diode D 980 , SCRs SCR 980 and SCR 981 , Darlington transistor Q 980 and opto-isolator U 980 .
The converter output is sensed at pin OUT+ reference to pin OUT−. Pin OUT+ is connected to resistor R 982 and to the cathode of zener diode D 980 . The anode of D 980 is connected to series resistor R 980 then to base of Q 980 . Resistor R 980 limits the base current to Q 980 . Resistor R 981 is connected between the anode of D 980 and return node OUT− to provide a diode leakage current path. Anode of light emitting diode U 980 is connected through resistor R 982 then to OUT+. The cathode of U 980 LED is connected to Q 980 collector. Emitter of Q 980 is connected to return node OUT−. Zener diode D 960 sets the maximum or trip voltage before transistor Q 980 is biased on providing current to U 980 LED. Application of voltage greater than the zener voltage of D 980 injects a small base current into Q 980 . Emitter of opto-isolator U 980 is connected to the gate of SCR 981 and through [R 984 ∥C 982 ] to return node BR−. Transistor Q 980 turns on the internal LED of U 980 placing phototransistor in a conducting state and supplying gate current to SRC SCR 981 from the external 18-volt source connected to pin CP 18 V+. Network [R 984 ∥C 982 ] prevents false triggering of SCR SCR 981 . The cathode of SCR SCR 981 is connected to the gate of SCR SCR 980 and through [R 985 ∥C 981 ] to return BR−. With SCR SCR 981 turned on gate current is provided to low voltage SCR SCR 980 . High voltage boost output is connected to pin PF+ resistor R 983 supplies hold current to SCR SCR 981 holding SCR SCR 980 on. SCR SCR 980 is selected for low hold current and ability to block the maximum boost voltage on PF+. SCR SRC 980 anode is connected to pin CP 18 V+. SCR SRC 980 cathode is connected to return pin BR−. SCR 980 clamps the low voltage supply CP ( FIG. 26 ) or CPA (FIG. 27 ). With the low supply held down the gate drive to the main switch is disabled turning off the converter. With the main switch Q 1 ( FIGS. 1 , 3 , 4 ) turned off holdup capacitor C 17 charges to applied AC line peak. With pin PF+ held near line peak SCRs SCR 981 will hold SCR SCR 981 on until AC line power is removed to the converter. Sub-circuit OVP 3 senses the out of specification output voltage and quickly stop the converter thereby protecting the load and converter with out generating destructive currents like OVP (FIG. 42 ).
FIG. 43 Push-pull oscillator sub-circuit PPG. Sub-circuit PPG is the push-pull oscillator sub-circuit of the invention. The current implementation uses a Motorola MC33025 pulse width modulator IC to generate the clock signals to drive the push-pull output stage. Sub-circuit PPG consists of U 14 a two-phase oscillator, resistors R 126 , R 130 , R 131 , R 132 , R 133 , R 134 , R 135 , R 136 and R 137 , capacitors C 143 , C 136 , C 139 , C 140 , C 141 and C 142 .
The current implementation uses a Motorola® MC33025 pulse width modulator IC to generate the clock signals to drive the push-pull stage. But, any non-overlapping two phase fixed frequency generator could be used. Pin 1 of U 14 is connected to [capacitor C 143 ∥Resistor R 132 ] then to pin 3 . Resistor R 134 connects the internal 5.1-volt reference output of U 14 pin 16 to pin 1 . Resistors R 135 in series with R 137 from 5.1-volt reference to return node PPG 0 form a voltage divider; the center is connected to U 14 pin 2 placing pin 2 at 2.55-volts. Resistor R 126 is connected from U 14 pin 5 to return node PPG 0 . Resistor R 133 is connected from U 14 pin 1 to return node PPG 0 . Timing capacitor C 142 is connected from U 14 pins 6 and 7 to return node PPG 0 . Resistor R 126 and capacitor C 142 set the operating frequency of the internal oscillator. Timing resistor could be replaced with a JFET, MOSFET, transistor, or similar switching device to provide variable frequency operation. The drain of the transistor would be connected to pin 5 . The source would be connected to return node PPG 0 . The variable frequency command voltage/current is applied between gate and source. Capacitor C 141 is connected from U 14 pin 8 to return node PPG 0 . Capacitor C 136 is connected from U 14 pin 16 to return node PPG 0 . Capacitor C 140 is connected from U 14 pin 15 to return node PPG 0 . Capacitor C 139 is connected from U 14 pin 13 to return node PPG 0 . Resistor R 136 is connected from U 14 pin 9 to return node PPG 0 . U 14 pins 10 and 12 is connected to return node PPG 0 . External power is connected to node/pin PPG+ to PWM (pulse width modulator) IC U 14 on pin 15 through resistor R 130 connected to the 18-volt control supply. Resistor R 131 connected to pin 13 of U 14 and PPG+ provides power to the totem-poll output stage. The power return line is connected to node PPG 0 . IC U 14 is designed to operate at a constant frequency of approximately 20-600 Khz with a fixed duty cycle of 35-49.9%. Resistors R 135 , R 137 , R 133 configure U 14 to operate at maximum pulse width. A two-phase non-over lapping square wave is generated on pins 11 node PH 2 and pin 14 node PH 1 and delivered to speed-up buffers AMP described in FIG. 29 . The two-phase generator is configured to prevent the issue of overlapping drive signals that would null the core bias and present excessive current to the switches. Sub-circuit PPG provides the drive to the push-pull switches making efficient use of the NSME.
FIG. 44 inrush limiter sub-circuit SS 1 . Sub-circuit SS 1 consists of diodes D 447 , resistors R 441 , R 442 , R 443 , R 444 , R 445 and R 446 , transistor Q 446 and capacitors C 449 , C 442 , and C 448 .
Node PF+ connects to the positive input of storage capacitor C 442 and to series resistors R 441 +R 442 . Series resistors R 441 and R 442 may be replaced with a single element. Series resistors R 441 and R 442 in parallel with provide a safety discharge path for C 442 . Drain of transistor Q 446 is connected to the negative terminal of C 442 and R 442 . Source of Q 446 is connected to return node BR−. Resistors [R 443 ∥R 445 ] are connected in parallel with Q 446 source and drain terminals. Resistors R 443 , R 444 and R 445 may be replaced with a single element. Resistor R 446 connects to the rectified line voltage node BR+ and to gate of Q 446 . Cathode of Zener diode D 447 is connected the gate of Q 446 . Anode of Zener diode D 447 is connected to source of Q 446 . Diode D 447 limits the maximum gate voltage to approx. 16 volts. Parallel capacitors C 448 and C 449 are connected in parallel to D 447 . Resistor R 446 and capacitors [C 448 ∥C 449 ] provide a time delay of (0.05 to 0.2 sec) at power up. This delay range is offered by way of example and not limitation. At power up transistor Q 446 is in a high impedance state. Thus capacitor C 442 charging current is limited by [R 443 ∥R 444 ∥R 445 ]. Referring to Interval 441 oscillograph G 44 ( FIG. 44A ) is the period when transistor is not conducting thus [R 443 ∥R 444 ∥R 445 ] provides the charging path thus limiting inrush current. Greatly reducing stress on the line filter and rectifier components during power up. The exponential decrease in inrush current is observed during interval 441 . Soft start-interval 444 ( FIG. 44A ) of oscillograph GPF+ is also marked with greater AC ripple voltage due to the series resistance. As capacitors [C 448 ∥C 449 ] charges through R 446 the gate voltage of Q 446 increases turning “ON” Q 446 . Transistor Q 446 turns on during interval 442 (FIG. 44 A). This action is marked by an increase in charging current 446 and a reduction in AC ripple during interval 445 . Similarly an exponential decrease in charging current is observed during 442 as C 442 charges. Transistor Q 446 is held in the conducting state until power is removed from the converter. During interval 447 the boost converter begins operation. Additional inrush limiting is provided by sub-circuit PWM ( FIG. 33 ) smoothly bringing up the output voltage during interval 448 . Shown by the increase in line current to full load during 443 . The instant invention provides settable inrush limiting intervals with simple resistor/capacitor value selection. Thus complementing the additional novel soft start boost circuit SS 1 . While maintaining high power factor during the start up interval. The graceful start up greatly reduces stress in the external fusing and components in the high current path. Enhancing MBTF with a minimal addition of components. This instant invention also permits “HOT” plugging multiple units in parallel for higher power and or redundancy. The inrush limiter SS 1 briefly isolates the storage capacitor from the main DC bus. In this way “hot swapping” does no create a large disturbance on the AC or main external DC BUS. The unique master less load sharing method taught in FIG. 4A allows any number of units to be connected in parallel for high power and reliability.
›ADDITIONAL EMBODIMENTS · 23 of 30
FIG. 44A is an oscillograph of line current and output voltage during operation of sub-circuit SS 1 (FIG. 44 ).
FIG. 45 is a schematic diagram of the fast start sub-circuit FS 1 . Fast-start Sub-circuit FS 1 consists of diodes D 452 and D 451 , resistors R 451 , R 452 , R 453 , R 454 , R 455 and R 456 , transistors Q 450 and Q 451 , and capacitors C 452 , C 453 , and C 451 .
Resistor R 451 connects node VCC to the base of transistor Q 450 , then to resistor R 454 in parallel with capacitor C 451 to ground or BR−. Anodes of zener diodes D 451 and D 452 are connected to ground. Cathode of zener diode D 451 is connected to emitter of Q 450 . Cathode of zener diode D 452 is connected to collector of Q 450 , gate of Q 451 and through resistors R 452 +R 453 to node PF+. Resistor R 455 connects from PF+ to drain of Q 451 . Resistor R 456 connects from BR− (ground) to source of Q 451 forming node TP 15 and through capacitor C 452 to the gate of Q 451 . Capacitor C 453 is connected between nodes TP 17 and TP 45 . With application of AC power node PF+ voltage increases rapidly. Transistor Q 450 is not in a conducting state as VCC is zero (no boost). Resistors R 452 +R 453 charge C 452 forward biasing Q 451 . Oscillograph G 45 ( FIG. 45A ) is plot of the source gate voltage of Q 451 . During interval G 451 , transistor Q 451 conducts providing power to VCC though R 455 from PF+. Interval G 452 of oscillograph GVCC shows the rapid rise of VCC. Thus full power is immediately available to the main switch Q 1 switch buffer AMP ( FIG. 29 ) and to the power factor controller PFA, PFB or PFB 1 . With VCC at or above 12.6V the boost converter gradually starts operation. This is seen by the small AC voltage present on TP 45 during interval G 454 (FIG. 45 A). Transistor Q 451 continues to provide power to VCC while the boost operation ramps up during the soft-start interval G 455 . Once the soft-start phase is completed, rectified AC via D 261 and D 260 provides power to VCC. Capacitor C 453 couples HF boost energy to quickly charge C 451 . R 451 provides continuous bias current to C 451 to prevent the activation of Q 451 when VCC is above 5 volts. Forward biasing Q 450 reduces the gate voltage on Q 451 . After interval G 456 transistor Q 451 gate to source is reverse biased turning off the fast-start. In the event of an over voltage condition from a high line condition or sudden load removal, boost activity will stop removing the AC voltage on TP 45 . Removal of this base drive reduces current in the collector circuit of Q 450 , thus allowing Q 451 to become forward biased if VCC falls below 5 volts. Power will be provided to VCC any time C 451 falls below 5 volts. This novel circuit provides a unique method to quickly provide control power before boost operation begins and maintain control power during extended over voltage or no load periods. Thus insuring rapid reliable start up and recovery under a full range of load and fault conditions.
FIG. 45A is an oscillograph of sub-circuit FS 1 during operation of sub-circuit SS 1 (FIG. 45 ).
FIG. 46 . Transient protection Sub-circuit TRN consists of diodes D 460 -D 462 , Bridge rectifier 461 and capacitors C 260 , C 262 and C 2 .
Line voltage AC plus a high voltage source HV 1 are connected to the AC-voltage terminals of bridge rectifier 461 . Bridge DC+ terminal connects to node BR+ and to Anodes of transient protection diodes D 460 -D 462 and inductor L 63 in parallel with capacitor C 20 . Inductor L 63 and capacitor C 20 do not substantially contribute to the action of the transient protection circuit and are only shown for completeness. Cathodes of D 460 -D 462 are connected to Boost output and storage capacitors C 2 and C 260 . Boost circuit operation is taught in FIGS. 18A , 30 , 29 , and 24 . Three transient protection diodes are offered by way of example and not limitation. The number of devices is a function of the selected device forward current capacity and the expected peak currents. Capacitor C 260 is a polarized electrolytic device and is offered by way of example and not limitation. A solid dielectric capacitor may be added in parallel to C 260 lower the impedance and improve the high frequency performance. During normal operation transient protection diodes D 460 -D 462 are reverse biased due to the action of the boost. With the application of a high voltage event HV 1 of any polarity to the AC line, the rectified event appears on node BR+, also shown in oscillograph G 463 (FIG. 46 B). If the transient voltage exceeds the voltage at C 2 , D 460 -D 462 are forward biased transferring the energy to storage capacitor C 260 . Common art transient methods shunt the energy into spark gaps or MOV type devices. These devices suffer from limited life cycles, excessive leakage currents or a catastrophic failure. With proper component selection very large transients may be absorbed with out exceeding device ratings. Thus insuring high reliability with minimal parts counts and cost. The instant invention is adaptable to other offline converters having a storage capacitor maintained (boosted) above the rectified peak line voltage. This topology will work with positive or negative reference converters.
FIG. 46 A. Transient protection Sub-circuit TRNX consists of resistor R 468 , Bridge rectifier BR 468 and capacitor C 468 .
Line voltage AC plus a high voltage source HV 1 are connected to the AC-voltage terminals of bridge rectifier BR 468 . Bridge output positive terminal connects to node BR+ and to resistor R 486 in parallel with C 468 . Bridge output negative terminal connects to node BR− and to resistor R 486 in parallel with C 468 . Sub-circuit TRNX may be connected in parallel with any AC or DC load requiring transient protection. With application of power to the bridge capacitor C 468 charges to peak voltage. Resistor R 468 bleeds off a small charge from C 468 . Once charging is complete only a small amount of power is dissipated by R 468 . During a transient event of the type depicted in graph G 462 ( FIG. 46B ) transient energy will be directed into capacitor C 468 . Low internal impedance of C 468 with the high forward current capability of BR 468 . Limits the magnitude of the transient, by directing the transient energy into C 468 . Generating a voltage oscillograph response G 461 . Additional capacitors may be added for higher voltages, currents and or lower impedance.
›ADDITIONAL EMBODIMENTS · 24 of 30
FIG. 46B is an oscillograph of the converter operation during a high voltage transient event. Oscillograph G 461 is the output voltage PF+. Oscillograph G 462 is the rectified AC line voltage BR+. Oscillograph G 463 is the gate voltage to the main boost switch Q 1 .
FIG. 47 is a signal diagram of supply auto load leveling. To teach the invention FIG. 47 only shows the essential elements for clarity. Power supplied to 473 enters regulator stage 470 . Regulator stage 470 may be any type such as series pass, variable reactance (AC) boost, buck and shunt. These are offered by way of example and not limitation. The regulator 470 only requires a control pin 479 that modulates the output N 470 in proportion to the control signal. Power or load sensing element 471 provides an output signal 472 that is proportional to the power delivered by 470 to load 476 . Load sensing element may be a hall effect sensor (Current), resistor with differential amplifier, watt sensor or current transformer. These are offered by way of example and not limitation. The requirement being that signal 472 is proportional to the power delivered. A simple inverting amplifier (not shown) may be required to level shift, buffer or invert signal 472 polarity for a specific sensor. By way of example VCC derived from the sampling the boost magnetic element PFT 1 A ( FIG. 4A ) via CP 1 ( FIG. 26A ) provides such a signal. Signal 472 (VCC) varies as a function of load as shown in FIG. 26 B. Load leveling is achieved with the addition of resistor R 476 connected between nodes 472 and 477 . Resistor R 345 in FIG. 4A is the corresponding component in the converter ACDCPF 1 . Power signal 472 is converted into a current through R 476 and injected into summing junction 477 . Summing junction 477 accepts current from R 473 proportional to the converter temperature from sensor T 473 . In this way converter load sharing is based on power and or temperature. Simple resistor ratios program load-sharing rates while maintaining converter regulation. Resistor R 479 develops a voltage proportional to the summing currents and applies it to the inverting terminal of comparator 478 . Reference voltage V 470 is applied to non-inverting input of comparator 478 . The comparator generates command signal 479 to modulate the regulator 470 . The action of the comparator is to maintain a minimal voltage difference between comparator input terminals. External power source(s) 475 and 475 N connect to output node N 474 and to common load 476 . This configuration allows many converters to be connected in parallel. Signal 472 (VCC) varies as a function of load as shown in FIG. 26 B. Load leveling is achieved with the addition of resistor R 476 connected between nodes 472 and 477 . Thus regulating the output voltage lower as the load increases. This unique action allows N units to be operated in parallel with out the typical master slave connections and circuitry. In this way the lightly loaded converters increase output voltage thus accepting more load. Like wise the heavy loaded converters will reduce voltage, automatically shedding load to other converters or sources. In this way any number of converters may be connected in parallel for high power or redundant applications. In common art master/slave configurations, loss of the master unit is catastrophic. In the instant invention failure or removal of a unit(s) causes the remaining units to increase output to absorb the additional load. Optional temperature sensor T 473 allows load sharing as a function of supply temperature in addition to load. Thus minimizing thermal gradients among multiple units. This auto load leveling method is adaptable to AC or DC sources. Component selection sets nominal operating voltages, and rates of load sharing. This method allows dynamic load sharing with out the typical master slave connections, costs, and reduced reliability. This method permits mixing of power supply types i.e. auto load sharing and only requiring their output voltages to be substantially equal. Thus providing excellent regulation, simple setup and configuration, “hot swap” capability automatic recovery from fault conditions.
FIG. 47A is an alternate signal diagram of supply auto load leveling. To teach the invention FIG. 47A only shows the essential elements for clarity. Power supplied to 473 enters the regulator stage 470 . Regulator stage 471 may be any type such as series pass, variable reactance (AC), boost, buck and shunt. These are offered by way of example and not limitation. The regulator 470 only requires a control pin 479 that modulates the output N 470 in proportion to the control signal. Power or load sensing element 471 provides an output signal 472 that is proportional to the power delivered by 470 to load 476 . Load sensing element may be a hall effect sensor (Current), resistor with differential amplifier, watt sensor or current transformer and are offered by way offered example and not limitation. The requirement being that signal 472 is proportional to the power delivered. A simple inverting A 470 amplifier may be required to level shift, buffer or invert signal 472 polarity for a specific sensor. By way of example VCC derived from the sampling the boost magnetic element PFT 1 A ( FIG. 4A ) via CP 1 ( FIG. 26A ) provides such a signal. Signal 472 (VCC) varies as a function of load as shown in FIG. 26 B. Amplifier A 470 , resistor R 478 and R 475 provides signal inversion to correct the signal polarity. Automatic load leveling is achieved with the addition of resistor R 476 connected between nodes output of A 470 and 477 . Resistor R 345 in FIG. 4A is the corresponding component in the converter ACDCPF 1 . Power signal 472 is converted into a current through R 476 and injected into reference junction N 476 . Reference voltage V 470 through R 470 to non-inverting input of comparator 478 . Thus effectively modulating the reference voltage to reduce the converter output voltage with higher powers. Summing junction 477 accepts current from R 475 proportional to the converter output N 474 . Thus enabling converter load sharing based on power. Simple resistor ratios program load-sharing rates and output voltages while maintaining converter regulation. Resistor R 479 develops a voltage proportional to the summing currents and is applied to the inverting terminal of comparator 478 . The comparator generates command signal 479 to modulate the regulator 470 . The action of the comparator is to maintain a minimal voltage difference between comparator input terminals. Additional external power source(s) 475 and 475 N connect to output node N 474 and turn to common load 476 . This configuration allows many converters to be connected in parallel. Thus regulating the output voltage lower as the load increases. This unique action allows N units to be operated in parallel with out the typical master slave connections and circuits. In this way the lightly loaded converters increase output voltage thus accepting more load. Like wise the heavy loaded converters will reduce voltage, automatically shedding load to other converters or sources. In this way any number of converters may be connected in parallel for high power or redundant applications. In common art master/slave configurations, loss of the master unit is catastrophic. In the instant invention failure or removal of a unit(s) causes the remaining units to increase output to absorb the additional load. This auto load leveling method is adaptable to AC or DC sources. Component selection sets nominal operating voltages, and rates of load sharing. This method allows dynamic load sharing with out the typical master slave connections, costs, and the reduced reliability. This method also permits mixing of power supply types i.e. auto load sharing and constant voltage types. Only requiring their stand alone output voltages to be substantially equal for a given load. This provides excellent regulation, simple setup and configuration, “hot swap” capability automatic recovery from fault Conditions.
›ADDITIONAL EMBODIMENTS · 25 of 30
FIG. 48 is an isometric view of the ITMS (integrated thermal management system). The ITMS 4800 consists of a thermally conductive block 4900 with a plurality of slots 4901 for semiconductor devices; 4810 , 4811 and 4812 along with a plurality of recesses 4904 and 4905 for accepting magnetic elements 4806 and 4807 . The thermally conductive block 4900 in the preferred embodiment is die-cast from Aluminum alloys. This is offered by way of example and not limitation, as other materials with similar thermal and mechanical properties could be used. The wire of the magnetic elements 4806 and 4807 are terminated with high-current terminals 5000 (as taught in FIG. 50 ) inserted into the alignment header 5200 (Detailed in FIG. 52 ). Magnetic elements 4806 and 4807 are mechanically mounted and thermally bonded to 4900 with thermally conductive materials. Sylgard #170 made by Dow Corning of Midland, Mich., USA is used in the preferred embodiment by way of example and not limitation. Semiconductor device 4811 located in recess 4901 is held in thermal contact to 4900 with novel thermal compression spring clip 5300 (FIG. 53 ). The number of semiconductors shown is by way of example and not limitation as additional devices may be added for multiple outputs. Additional semiconductor devices may be attached with novel thermal compression clamp 5400 ( FIG. 54 ) to 4900 or walls of thermally conductive case not shown. The ITMS has a number of rugged compact system benefits. One of these benefits is low thermal resistance for semiconductors and the magnetic elements 4806 and 4807 into the thermally conductive block 4900 . Another benefit is the short connection length between semiconductors and magnetic elements, thus further reducing copper losses and leakage inductance in the PCB (not shown). Additionally, the thermally conductive block 4900 provides EMI shielding for the magnetic elements. Current electrolytic capactior art, life is limited to a few thousand hours at temperatures near 100 C. Cooling filter capacitors with the ITMS further enhances product life.
FIG. 49 is the thermally conductive block 4900 with a plurality of slots 4901 , and 4902 for semiconductor devices (not shown), a plurality of recesses 4904 and 4905 for accepting magnetic elements 4806 and 4807 , and a plurality of recesses 4906 for accepting capacitors. The thermally conductive block 4900 may be cast, molded or machined. The preferred embodiment of 4900 is die-cast from Aluminum alloys or other thermally conductive materials. This is offered by way of example and not limitation, as other materials with similar thermal and mechanical properties could be used. Another alternate embodiment 4900 is molded with the components from a conductive epoxy material such as Ryton PPS made by Phillips Chemical, of Bantleville, Okla. USA eliminating the additional conductive resin resulting in a more reliable monolithic block. Magnetic elements 4806 and 4807 are mechanically mounted and thermally bonded to 4900 with thermally conductive materials. Semiconductor devices are held in thermal contact with the thermally conductive block 4900 using clip 5300 . The number of devices to be mounted is by way of example and not limitation as the system may be made larger to accommodate additional parts for multiple outputs.
FIG. 50 is a detailed view of the high performance, multiple pin, and high-current terminals. The high-current terminal 5000 consists of a conductive body 5001 with a pair of tabs 5003 and plurality of lead pairs 5002 . Tabs 5003 are formed upward at least 90-degree angles to the body 5001 . External conductors (not shown) are held between the body 5001 and the tab 5003 by crimping tab 5003 and the application of solder. Pins 5002 are formed downward at 90-degree angles to the body 5001 . Pins 5002 are inserted into an alignment header (Example: FIG. 52 , part number 5200 ) for subsequent alignment into main PWB (not shown). Tapered surface 5005 guides the lead into the receiving frame 5201 holes. The number of lead pairs 5002 is proportional to the expected current. In the preferred embodiment ( FIG. 50 ) has four pairs for 40+ ampere service. This is offered by way of example and not limitation. The high-current terminal provides a small profile, positive location and low-resistance connection.
FIG. 51 is another example of how a metal cup 5101 and thermally conductive material is used to remove heat from a magnetic element 5102 . It also shows how high-current terminals 5000 are inserted into an alignment header 5103 and how the wires 5104 coming off the boost inductor are terminated. The alignment header permits pre-testing of the assembly and aids in ease of component installation during manufacturing. It also allows for an overall low profile of the unit.
FIG. 52 is the top view of the alignment header 5200 . The current embodiment is machined from a glass-epoxy PWB material. The preferred embodiment is molded out of a non-conductive, high-strength material. This material is offered by way of example and not limitation. High-current terminals 5000 (not shown) are inserted into receiving holes 5201 . The alignment header 5200 offers a convenient way to hold high-current terminals in alignment for final assembly onto the integrated thermal management system 4900 (FIG. 49 ).
FIG. 53 is a detailed view of thermal compression spring clip 5300 . The thermal compression spring clip 5300 is fabricated from a strip of beryllium copper using a simple progressive stamping process. This material and fabrication method is offered by way of example and not limitation. Flat surface 5301 of the thermal compression spring clip 5300 presses against semiconductor body 4811 as shown in FIG. 48 , clip 5300 . Curved surface 5302 forms a spring providing the compression force to hold the semiconductor firmly against 4900 (FIG. 49 ). The spring 5300 also transfers heat to the opposite surface of the slot 4901 (FIG. 49 ). In this way heat is removed from both surfaces of the semiconductor. The spring also incorporates a taper at edge 5303 allowing insertion in the space between semiconductor body 4811 and thermal block 4900 without special tools. Tab 5304 provides both a surface for insertion as well as a positive mechanical stop. The novel thermal compression spring clip allows for quick assembly and replacement of semiconductors. It also maintains a high clamping force without fasteners, as described in prior art, that resists vibration over a wide temperature range.
›ADDITIONAL EMBODIMENTS · 26 of 30
FIG. 54 is a detailed view of the thermal compression clamp 5400 . The thermal compression clamp 5400 is used to secure semiconductor component 5401 to substrate 5408 . The thermal compression clamp 5400 is fabricated from a strip of stainless steel in the preferred embodiment using a simple progressive stamping process. This material and fabrication method is offered by way of example and not limitation. The semiconductor body 5401 is held securely against the flat surface of the heat sink using the thermal compression clamp 5400 . Flat surface 5402 are held under pressure against the heat sink using a fastener 5407 through hole 5403 . Curved section 5404 forms a spring providing the compression force to hold the semiconductor firmly in place. Section 5406 is curved upward to simplify insertion of the semiconductor 5401 during manufacturing. The spring 5400 also transfers heat from the opposite surface of the semiconductor body. In this way heat is removed from two surfaces of the semiconductor. This novel thermal compression spring clip allows for quick assembly and the replacement of semiconductors with out tools.
FIG. 57 is the schematic of the preferred inter-stage inrush limit sub-circuit ISIR. Sub-circuit ISIR consists of resistors R 5701 , R 5703 , R 5704 , R 5707 , R 5706 , R 5711 , R 5714 , R 5715 , R 5716 , R 5717 , R 5718 , R 5719 , R 5720 , R 5721 , R 5722 , R 5723 , R 5724 , R 5725 and R 5726 , Opto-isolator U 5710 , amplifiers U 5712 and U 5713 , capacitors C 5705 , C 5707 and C 5708 diode D 5706 transistors Q 5700 , Q 5702 , Q 5708 , Q 5709 and thermal switch TS 5728 .
FIG. 57 Table Element Value/part number C5705 0.4 uf 35 v C5707 1000 pf 100 v C5708 220 pf 100 v D5706 Zener 24 v/500 mw Q5700 APT5020BVR Q5702 2n2222 Q5708 FTZ851 Q5709 2n2222 R5701 1.0k ohm R5703 22.0k ohm R5704 340.0k ohm R5707 0.05 ohms R5706 10 ohms R5711 2.0 ohm R5714 1.5k ohm R5715 10.0k ohm R5716 10.0k ohms R5717 22.1k ohms R5718 10.0k ohms R5719 402k ohm R5720 1.33k ohm R5721 69.8k ohms R5722 10.0k ohms R5723 10.0k ohms R5724 100k ohm R5725 34.0k ohm R5726 10.0k ohms U5710 NEC2501 U5712, U5713 MC34072 TS5728 67F105 (105C)
The output of the previous PFC stage at pin PF+ is connected to drain of Q 5700 . Output and common node PPIN connects to capacitors C 5707 , C 5708 and C 5725 , resistors R 5704 , R 5722 and R 5718 , pin 4 of amplifiers U 5712 and U 5713 , emitters of transistors Q 5708 , Q 5709 and U 5710 . Current sample from node formed by source of Q 5700 second side of R 5707 and C 5705 connects through series resistor R 5723 to pin 3 of amplifier U 5713 and second side C 5708 . Second side of R 5722 connects to pin 2 of amplifier U 5713 and through series resistor R 5721 to pin 7 of amplifier U 5713 . First side of series resistor R 5719 , in parallel with series resistor R 5720 and diode D 5706 . Second side of R 5719 connects to U 5712 pin 6 , second side of C 5707 . Second side of R 5718 connects to pin 5 of amplifier U 5712 and second side of R 5725 and R 5715 . Power node VCC 2 connects second side of resistors R 5724 , R 5714 and R 5725 and pin 8 of amplifiers U 5712 and U 5713 . Amplifier output U 5712 pin 7 connects to first side of R 5715 through series resistor R 5717 to base of transistor Q 5709 . Transistor collector Q 5709 connects to first side of R 5714 and to base of transistor Q 5708 . Transistor collector Q 5708 connects through series resistor R 5711 to second sides of C 5705 and R 5704 through series resistor R 5706 and to gate of transistor Q 5700 . Opto-isolator transistor collector U 5710 connects to second side of R 5716 . External remote enable REN connects through series thermal switch TS 5728 through series resistor R 5703 to base of transistor Q 5703 and through series resistor R 5726 to VCC 3 . Transistor collector Q 5702 connects through series LED U 5710 and through series resistor R 5701 to power node VCC 3 . Voltage drop developed across current sense resistor R 5707 is amplified by U 5713 . Output of amplifier U 5713 is applied to damped peak detector formed by diode D 5706 , resistor R 5719 , and capacitor C 5707 . Trigger level and hysterisis of comparator U 5712 is set by the ratios of R 5725 , R 5718 and R 5715 . In this way the over current trip level may be set to any value. Amplifier U 5712 output is buffered by transistors Q 5709 and Q 5708 to turn off FET Q 5700 . With application of AC power to the bias supply CP 3 ( FIG. 65 ) node VCC 2 is set to 15-volts relative to PPIN. Capacitor C 5705 and Q 5700 gate charges slowly through time delay resistors R 5704 to the VCC 2 voltage. As low ON resistance transistor Q 5700 turns on it passes though its linear region. Thus providing a short controlled application of power to the output stage. By applying power in a controlled way stress to components in the output stages is reduced thereby enhancing reliability. The over-current fold back provides additional protection to main switch transistors Q 1 , Q 6 and Q 9 from excessive loads. Normally closed thermal switch TS 5728 is in contact with main switch transistor Q 1 . In the event of temperature greater than 105 C TS 5728 opens, base current to Q 5702 is provided by R 5726 causing switch Q 5700 to open. When switch temperature returns to operational range TS 5728 will close, applying power to the output stage.
FIG. 58 is the schematic of the preferred embodiment of the output controller sub-circuit OUTC. Sub-circuit OUTC consists of resistors of R 5801 , R 5802 , R 5803 , R 5804 , R 5805 , R 5806 , R 5807 and R 5808 , capacitors C 5709 , C 5810 , C 5811 , C 5812 C 5813 , FET transistor Q 5814 , opto-isolator U 5816 and control element U 5800 .
The output ( FIG. 25 ) of the main rectifier/filter stage OUTA at pin OUT+ is connected through resistor R 5802 to pin 1 of U 5800 , second side capacitor C 5813 and anode of D 5815 . Node OUT+ is also connected through resistor R 5801 to pin 8 of U 5800 then through resistor R 5803 to pin 9 of U 5800 then through resistor R 5804 to return node OUT−. Common node OUT− connects to C 5813 , R 5804 , C 5809 , C 5810 , C 5811 , C 5812 , R 5805 and pin 5 of U 5800 . Second side capacitor C 5810 is connected to U 5800 pin 10 . Second side capacitor C 5811 is connected to U 5800 pin 3 . Second side capacitor C 5809 is connected to U 5800 pin 9 . Second side capacitor C 5812 is connected through series resistor R 5808 to gate of Q 5814 and U 5800 pin 6 . Drain of Q 5814 connects to U 5816 emitter, output node OUTS−, through series resistor R 5807 to U 5800 pin 7 . Collector of Q 5816 connects to output node POK through series resistor R 5815 to power VCC 3 . Source of Q 5814 connects to U 5800 pin 4 and through series sense resistor R 5805 to OUT−. Output status node U 5800 pin 2 connects through series resistor R 5806 and to cathode of LED D 5815 . Controller element U 5800 turns off gate drive to transistor Q 5814 for over/under voltage and over current conditions and asserts pin 2 low. Resistors R 5801 , R 5803 and R 5804 program the over/under voltage set points. Resistor R 5805 programs the over current set point at 50-millvolts equals max current. Output controller U 5800 made by Linear Technology, Milpitas Calif. or its equivalent is offered by way of example and not limitation. Output controller OUTC protects the load from over and under voltage and the converter from over current conditions.
›ADDITIONAL EMBODIMENTS · 27 of 30
FIG. 59 is a schematic diagram of the preferred AC inrush limiter sub-circuit ACIR of the invention. The AC inrush limiter sub-circuit ACIR is comprised of transistor Q 5900 , capacitor C 5901 , resistors R 5902 , R 5903 , thermistor T 5904 , relay K 5905 and diode D 5906 .
FIG. 59 Table Element Value/part number Q5900 Nch FET NDS355A C5901 10 ufd/35 v R5902 66.5k ohms R5903 33.7k ohms T5904 SL22 100008 K5905 ALZF22 Single pole D5906 90 v/0.4 Amp
Node L 2 is connected to external AC line then to normally open contact of relay K 5905 and to the first terminal of thermistor T 5904 . AC output Node L 1 is connected the second normally open contact of relay K 5905 and to the second terminal of thermistor T 5904 . Anode of D 5906 connected to drain of Q 5900 and the coil of relay K 5905 . The cathode of D 5906 is connected 15-volt bias supply node VCC, R 5902 and the second side of relay coil K 5905 . Second side of R 5902 connects to gate of Q 5900 and resistor R 5903 and capacitor C 5901 . Return node BR− connects to the drain terminal of Q 5900 , second side of resistor R 5903 and capacitor C 5901 . Application of power to VCC node charges gate of Q 5900 through resistor R 5902 turning on Q 5900 energizing relay K 5905 . Resistors R 5903 , R 5902 and capacitor C 5901 values determine the time delay. This simple circuit reduces stress on external fuses and AC front-end components during turn on.
FIG. 60 is the schematic of the preferred embodiment of the sub-circuit ACOKC. Sub-circuit ACOKC consists of resistors R 6000 , R 6001 , R 6002 , R 6003 , R 6004 , R 6005 , R 6006 , R 6007 , R 6008 , R 6009 , R 6010 , R 6011 , R 6012 and R 6013 diodes BR 6019 , D 60016 and D 6019 , capacitors C 6014 and C 6015 comparators U 6017 B and U 6018 A.
AC line node LL 5 connects through series resistor R 6000 to pin 2 of bridge rectifier BR 6019 . AC line node LL 6 connects through series resistor R 6001 to pin 3 of bridge rectifier BR 6019 . Common node BR− connects to pin 4 of bridge rectifier BR 6019 , resistors R 6004 , R 6003 , R 6009 and R 6010 capacitors C 6015 and C 6014 , pin 4 of comparators U 6017 B and U 6018 A. Rectified AC line from BR 6019 pin 1 connects through series resistor R 6002 to pin 5 of comparator U 6017 B and first side of R 6006 . Second side of R 6006 connects to pin 7 of comparator U 6017 B and first side of R 6007 and R 6008 . Second side of R 6008 connects to series diode D 6016 anode. Cathode of diode D 6016 connects to pin 2 of comparator U 6018 A and second side of R 6009 and C 6015 . Power node VCC 1 connects second side of resistors R 6005 , R 6007 , R 6011 and R 6014 capacitor C 6014 and pin 8 of comparators U 6017 B and U 6018 A. Amplifier U 6018 A pin 3 connects through series resistor R 6012 to pin 1 of amplifier U 6018 A and first side of R 6011 and R 6013 to output node ACOK. Rectified AC line from BR 6019 pin 1 is attenuated by resistors R 6002 and R 6003 and buffered by comparator U 6017 B. Output of comparator U 6017 B is applied to damped peak detector formed by diode D 6016 , resistor R 6009 , and capacitor C 6015 . Trigger level and hysterisis of comparator U 6018 A is set by the ratios of R 6011 , R 6012 and R 6010 . In this way the minimum AC line voltage may be set to any value; in the preferred embodiment the level is set to 170 VAC for a valid ACOK signal. The ACOK signal is used to inhibit boost action to protect the converter and also to alert the user that a loss of power has occurred.
FIG. 61 is a schematic representation of the NSME PFT 2 Sub-circuit transformer PFT 2 consists of a primary winding 6100 around a NSME 6101 with a current sense winding 6102 .
The primary winding 6100 has nodes P 1 B and P 1 A for connections to external AC source. Secondary 6102 winding has nodes S 1 H and S 1 L connections. Current sense winding 6102 are connected to feed back network of sub-circuit PFCB (FIG. 63 ). Magnetic element 6101 comprises non-saturating, low permeability magnetic material.
FIG. 62 is a schematic showing alternate line filter LFB. The filter sub-circuit LFB comprises capacitors C 6201 , C 6202 , C 6204 , C 6205 , C 6206 , C 6209 , inductors L 6200 , L 6207 , magnetic elements L 6203 , L 6208 , and diodes D 20 -D 23 .
FIG. 62 Table Element Value/part number L6200 5.2 mH common mode H 42507-TC core 18 T bifilar L6203 36 uH differential mode 15T 77930-A7 core L6207 5.2 mH common mode 42507-TC core 18 T bifilar L6208 500 uH 77930-A7 core C6201 0.1 Uf C6202, C6204 0.47 Uf C6205, C6206 4.7 nf Y-cap C6209 0.047 uF 500 v D20 1000 V/25 A D21 1000 v/25 A D22 1000 v/25 A D23 1000 v/25 A
The AC line is connected to nodes LL 2 and LL 1 . Node LL 2 connects through upper leg of inductor L 6200 to first leg of capacitor C 6201 then to capacitor C 6202 then to upper leg of Bifilar wound inductor L 6203 . Node LL 1 connects to second leg of capacitor C 6201 then through lower leg of inductor L 6200 to second leg of capacitor C 6202 then to lower leg of Bifilar wound inductor L 6203 . From second lower leg of L 6203 connects to second leg of capacitor C 6204 and to first leg of y-cap C 6206 then through lower leg of inductor L 6207 to anode of diode D 23 and cathode of diode D 21 . From second upper leg of L 6203 connects to first leg of capacitor C 6204 and to first leg of y-cap C 6205 then through upper leg of inductor L 6207 to anode of diode D 20 and cathode of diode D 20 . Center legs of Y-caps C 6205 and C 6206 are connected to chassis return LL 0 . Anodes of diode D 20 and D 21 connect to form node BR−. Cathodes of diodes D 22 and D 23 connect to NSME L 6208 in parallel with C 6209 and node BR+. The other side of L 6208 in parallel with C 20 forms node B+. Common mode inductors L 6200 and L 6207 are constructed on a high permeability core material 42507-TC manufactured by Magnetics inc. Butler Pa. USA. This material is offered by way of example and not limitation. The instant invention takes advantage of the high permeability properties of the ferrite used in inductors L 6203 and L 6208 . (see FIG. 15 A), making full use of the core material over all four quadrants. Inductors L 6200 and L 6207 are effective in removing common mode EMI components. Both NSME L 6203 and L 6208 in parallel with C 6209 effectively block differential mode noise generated by switch Q 1 . Inductor L 6208 is operated in the first quadrant taking advantage of the unique non-saturating properties of the KoolMu material and is offered by way of example and not limitation. This embodiment is an improvement over sub-circuit LF (as taught in FIG. 20A ) with its enhanced conducted noise attenuation performance. The instant invention makes optimal use of the ferrite type material in the AC side and the desirable NSME in the DC side to provide high performance filtering at a low cost.
›ADDITIONAL EMBODIMENTS · 28 of 30
FIG. 63 is the preferred power factor controller sub-circuit PFC for isolated converters. Sub-circuit PFC consists of components R 6300 , C 6301 , D 6302 , C 6303 , C 6304 , R 6305 , R 6306 , R 6307 , Q 6308 , D 6309 , R 6310 , R 6311 , C 6312 , and control element IC U 6313 .
Element Table FIG. 63 Value/part number R6300 30.1k/8.45 ohms 1% C6301 0.01 uf NPO D6302 90 v.4a low leakage C6303 0.33 uf C6304 .01 uf NPO R6305 931k ohms 1% R6306 931k ohms 1% R6307 100k VO trim Q6308 Mmbt2222 D6309 90 v.4a low leakage R6310 30.1k 1% R6311 10K C6312 .1 uf U6313 MC33260 (Motorola) or equivalent
Control element U 6313 is an 8 pin bi-cmos controller. The pins function as follows:
Pin 1 : The circuit uses an on-time control mode. This on-time is controlled by comparing the CT voltage to the V control voltage. CT is charged by the squared feedback current. Pin 2 : This pin is designed to receive a negative voltage signal proportional to the current flowing through the inductor. This information is generally built using a sense resistor. The Zero Current Detection prevents any restart as long as the pin 4 voltage is below (−60 mV). Pin 3 : This pin is designed to receive a synchronization signal. For instance, it enables to synchronize the PFC preconverter to the associated SMPS. If not used, this pin must be grounded. Pin 4 : This pin must be connected to the preregulator ground. Pin 5 : The gate drive current capability is suited to drive an IGBT or a power MOSFET. Pin 6 : This pin is the positive supply of the IC. The circuit turns on when VCC becomes higher than 11V, the operating range after start-up being 8.5V up to 16V. Pin 7 : This pin is designed to receive a current that is proportional to the preconverter output voltage. This information is used for both the regulation and the overvoltage and undervoltage protections. The current drawn by this pin is internally squared to be used as oscillator capacitor charge current. Pin 8 : This pin makes available the regulation block output. The capacitor connected between this pin and ground, adjusts the control bandwidth. It is typically set below 20 Hz to obtain a non-distorted input current.
Control element U 6313 connects to a circuit with the following connections: from pin 7 to node/pin PF 1 to capacitor C 6304 in series with ground. Pin 7 is the input to an internal regulation block and connection to external feedback networks. This pin is designed to receive a current that is proportional to the preconverter output voltage PF+. (See FIGS. 40 , 40 A, 40 B, 40 C, 40 D and 64 ) Increasing the current on pin 7 decreases the pulse width of the PFCLK node pin 5 . Node PFSC is not used with this controller. Bias power for the PFC controller is applied to node PFB+ and to U 6313 pin 6 . Output clock node PFCLK is connected to U 6313 pin 5 to external buffer sub-circuit AMP (FIG. 29 ). PFVC is connected through R 6300 to the anode of D 6302 and pin 2 node of U 6313 . The cathode of D 6302 is tied to pin 1 of U 6313 . C 6301 is connected from U 6313 pin 1 to ground. Pin 3 of U 6313 tied to pin 4 , which is the ground pin of U 6313 . Capacitor C 6303 is connected from U 6313 pin 8 to return node BR−. The addition of current from the sense winding of the boost inductor 6102 ( FIG. 61 ) through D 6302 to C 6301 and pin 1 of U 6313 creates a feed forward proportional current which improves power factor, efficiency, and EMI. When this current is summed with the current at pin 1 , the resulting line load dynamic ramp on C 6301 improves the pattern of modulation at pin 5 to better conform with the AC line across a wider range of line load conditions. This is true because the ramp at pin 1 controls the cycle-by-cycle pulse width behavior of the controller.
FIG. 64 is the preferred power factor controller used in the single stage power factor controller ACDCPF 2 sub-circuit PFD for non-isolated converters. Sub-circuit PFD consists of components R 6400 , C 6401 , D 6402 , C 6403 , C 6404 , R 6405 , R 6406 , R 6407 , D 6409 , R 6410 , R 6411 , R 6420 , R 6421 , R 6423 , capacitors C 6464 , C 6412 , transistors Q 6408 , Q 6415 and Q 6422 and control element IC U 6413 .
Element Table FIG. 64 Value/part number R6400 30.1k/8.45 ohms 1% C6401 0.01 uf NPO D6402 90 v.4 a low leakage C6403 0.33 uf C6404 .01 uf NPO R6405 931k ohms 1% R6406 931k ohms 1% R6407 100k VO trim Q6408 Mmbt2222 D6409 90 v .4 a low leakage R6410 30.1k 1% R6411 10K C6412 .1 uf U6413 MC33260 (Motorola) or equivalent R6420 1 MEG ohm R6421 100K ohm Q6422 NDS355An N-CH FET R6423 23.1k ohm C6424 0.22 ufd 50 V Q6425 2n2222
The boost behavior of ACDCPF 2 is the same as taught in ACDCPF 1 ( FIG. 63 ) with the addition of low line voltage detection circuitry that stops boost activity until line voltage returns to a preset minimum voltage. This is to protect the main switch Q 1 from damage during line dips. Control element U 6413 is an 8 pin bi-cmos controller. The pins function as follows:
Pin 1 : The circuit uses an on-time control mode. This on-time is controlled by comparing the CT voltage to the V control voltage. CT is charged by the squared feedback current. Pin 2 : This pin is designed to receive a negative voltage signal proportional to the current flowing through the inductor. This information is generally built using a sense resistor. The Zero Current Detection prevents any restart as long as the pin 4 voltage is below (−60 mV). Pin 3 : This pin is designed to receive a synchronization signal. For instance, it enables to synchronize the PFC preconverter to the associated SMPS. If not used, this pin must be grounded. Pin 4 : This pin must be connected to the preregulator ground. Pin 5 : The gate drive current capability is suited to drive an IGBT or a power MOSFET. Pin 6 : This pin is the positive supply of the IC. The circuit turns on when VCC becomes higher than 11V, the operating range after start-up being 8.5V up to 16V. Pin 7 : This pin is designed to receive a current that is proportional to the preconverter output voltage. This information is used for both the regulation and the overvoltage and undervoltage protections. The current drawn by this pin is internally squared to be used as oscillator capacitor charge current. Pin 8 : This pin makes available the regulation block output. The capacitor connected between this pin and ground, adjusts the control bandwidth. It is typically set below 20 Hz to obtain a non-distorted input current.
›ADDITIONAL EMBODIMENTS · 29 of 30
Rectified AC line node BR+ connects through series resistor R 6420 to gate of transistor Q 6422 to first side of R 6423 and first side of C 6424 . Power node VCC 1 connects through series resistor R 6421 to base of Q 6425 and drain of Q 6422 . Common node BR− connects to emitter of Q 6425 , source of Q 6422 , second side of R 6423 and second side of C 6424 . Open collector output node VCNT connects to collector of Q 6425 . When the node BR+ line reaches approximately 75-VDC, Q 6422 turns on removing base current to Q 6425 . With transistor Q 6425 off control node VCNT is allowed to float thus allowing normal boost regulation developed by PFC (FIG. 63 ). This novel circuit shuts down the boost regulator before it enters an unstable area of operation at low line voltages.
FIG. 65 Is a schematic drawing of the sub-circuit CP 3 . Sub-circuit CP 3 consists of bias power supply module 6500 .
FIG. 65 Table Element Value/part number 6500 +15, +5, −15 100 ma bias supply
Bias 6500 supply made by Bias Power Technology Inc. 414 Vermont Street Palatine, Ill. USA. Provides three regulated isolated outputs of +15-volts, +5-volts and −15-volts. AC line power is applied to terminals LL 5 and LL 6 . Regulated isolated output nodes VCC 1 and BR− supplies 15-volts. Regulated isolated output nodes VCC 2 and PF+ supplies 15-volts. The use of isolated outputs allows N-ch FETs with lower on resistance in the inrush limit sub-circuit Isolated output nodes VCC 3 and OUT− supplies 5-volts. Used for regulator circuits and output switch drive during normal operation.
FIG. 66 Alternate control power sub-circuit CP 2 Sub-circuit CP 2 consists of diodes D 6633 , D 6637 and D 6638 , inductor L 6636 , resistors R 6632 and R 6635 , transistor Q 6631 , and capacitors C 6634 , and C 6631 .
Node CT 1 A connects to anode of D 6637 and to the upper external center tapped secondary winding. Node CT 2 A connects to anode of D 6638 and to the lower external center tapped secondary winding. Node BR− connects to the external winding center tap. Node BR− is also the return line and it connects to Zener diode D 6633 anode, and capacitors C 6634 and C 6631 . The cathodes of diodes D 6637 and D 6638 are connected through series inductor L 6636 and resistor R 6635 . The other side of resistor R 6635 connects to collector Q 6631 , second side of C 6634 and first side of R 6632 . Second side of Resistor R 6632 is connected to capacitor C 6630 , base Q 6631 , cathode of diode D 6633 . Emitter of Q 6631 is connected to second sides capacitors C 6630 and C 6631 and node PFA+. The zener diode voltage is selected at 18-Volts to begin regulation at high boost levels. Voltage limiting starts at levels near full load (maximum boost). This unique behavior has three benefits. First at greater levels of boost (load) additional gate voltage is automatically provided to the main switch Q 1 when maximum gate power is required. Second automatically lowering gate voltage at minimal boost reduces the stress on the main switch Q 1 gate and associated buffer components, thus enhancing MBTF and efficiency. Third the components are selected such that the limiting begins near maximum boost. In this way, power is not wasted at small load levels. Additionally the main switch Q 1 gate voltage is modulated to provide additional power at maximum boost insuring maximum efficiency under varying load conditions.
FIG. 67 is a schematic diagram of a diode snubber sub-circuit SCIN of the invention. The snubber sub-circuit SCIN is comprised of diode D 6701 .
Pin SNL 2 is connected to the anode of D 6701 the cathode of D 6701 is connected node SNOUT. Node SNL 2 connects to the drain terminal of the external output switch and to flyback side of the inductive load. The external fly-back rectifier diode D 4 ( FIGS. 56 and 55 ) anode is connected to node SNL 2 node SNOUT connects flyback diode D 4 . External diode D 4 in parallel with SCIN forms a hybrid diode. This hybrid diode begins rectification immediately after the main switch stops conduction and the non-saturating magnetic begins releasing its energy. This characteristic is due to SIC extremely high electron mobility of Saturated Electron Drift Velocity 2.0×10^7 cm/sec (at E 2×10^5 V/cm). The SIC diode has a greater forward voltage drop of Approx 1.3 volts than that of the fast recovery diode D 4 at less than 1.1 volt. The UPSC600 made by Microsemi Corporation 2381 Morse Avenue Irvine, Calif. USA is used in the preferred embodiment. And is offered by way of example and not limitation as other similar devices are offered by this and other manufactures. The novel combination of a ‘slower’ diode D 4 with low forward voltage drop in parallel with a high speed SIC diode ‘catches’ the fly-back energy missed buy the standard diode alone. The energy missed in the first 30-100 nsec by D 4 is recovered by the SIC diode resulting in a significant efficiency gain of approx 0.3%.
FIG. 68 is a schematic diagram of the preferred non-isolated boost output voltage feed back sub-circuit VFBI Sub-circuit FBD consists of Resistor R 6801 and adjustable resistor R 6802 .
Input node PF+ connected to series resistor [R 6801 ] then to wiper arm of R 6802 and second side of R 6802 . First side of R 6802 is connected to the feed back node PF 1 . Resistor values are selected for a nominal input voltage of 385-volts. Feedback output node PF 1 is connected to node PF 1 of sub-circuit PFC ( FIG. 63 ) or PFD (FIG. 64 ). Component values are selected to provide a 15-volt adjustment range.
FIG. 69 Push-pull oscillator sub-circuit PPGA is the preferred push-pull oscillator sub-circuit of the invention. Sub-circuit PPGA consists of U 6900 a two-phase oscillator, resistors R 6902 , R 6901 , and R 6903 , capacitors C 6906 , C 6904 and C 6905 .
The current implementation uses a Motorola MC33025 pulse width modulator IC to generate the clock signals to drive the push-pull stage. This is offered by way of example and not limitation, as any non-overlapping two phase fixed frequency generator may be used. Pin 1 of U 6900 is tied to pin 3 . The internal 5.1-volt reference output of U 6900 pin 16 connects to capacitor C 6906 and series resistor R 6901 connects to U 6900 pin 2 . Resistor R 6902 is connected from U 6900 pin 5 to return node PPG 0 . Resistor R 6903 is connected from U 6900 pin 9 to return node PPG 0 . Timing capacitor C 6905 is connected from U 6900 pins 6 and 7 to return node PPG 0 . Resistor R 6902 and capacitor C 6905 set the operating frequency of the internal oscillator at approximately 90 Khz. Timing resistor R 6902 could be replaced with a JFET, transistor, or digital resistor to provide variable frequency operation. Capacitor C 6904 is connected from U 6900 pin 8 to return node PPG 0 . Capacitor C 6906 is connected from U 6900 pin 16 to return node PPG 0 . Power input node PPG+ connects to U 6900 pins 15 and 13 . Return node PPG 0 connects to U 6900 pins 10 and 12 . IC U 6900 is configured to operate at a constant frequency of approximately 20-600 Khz with a fixed duty cycle of 35-49.9% with 49% being nominal. A two-phase non-over lapping square wave is generated on pins 11 node PH 2 and pin 14 node PH 1 and delivered to speed-up buffers AMP described in FIG. 29 . The two-phase generator is configured to prevent the issue of overlapping drive signals that would null the core bias and present excessive current to the switches. Sub-circuit PPGA provides the drive to the push-pull switches making efficient use of the NSME.
›ADDITIONAL EMBODIMENTS · 30 of 30
FIG. 70 is a schematic diagram of the preffered push-pull converter snubber sub-circuit SNDD of the invention. The snubber sub-circuit SNDD is comprised of resistor R 7001 , diode D 7002 , and capacitor C 7000 .
Node SNA 3 connects through capacitor C 7000 to cathode of diode D 7002 in parellel with resistor R 7001 . Node SNAL connects to the anode D 7002 . SNAL connects to the drain terminal of the external output switch and to flyback side of the inductive load. The “snubbering”action slows the rise of the flyback giving time for the external rectifier diode(s) to begin conduction.
Although the present invention has been described with reference to a preferred embodiment, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.
Representative of the Art is:
U.S. Pat. No. 5,875,103 (1999) to Bhagwat et al discloses a soft-switching DC to DC power converter which minimizes switching losses from a no load condition to a full load condition while operating at fixed frequency. U.S. Pat. No. 5,812,383 (1998) to Majid et al. discloses a switched-mode converter circuit having an operating mode and a stand-by mode. U.S. Pat. No. 5,742,495 (1998) to Barone discloses an invention that relates to electrical conversion between electrical systems, e.g. inversion. U.S. Pat. No. 5,715,153 (1998) to Lu discloses a multi-output power supply, which receives a DC, input voltage and generates a first DC output voltage, and a buck regulator circuit, which receives the first DC output voltage. U.S. Pat. No. 5,392,206 (1995) to Peterson et al. discloses a DC-DC power converter having a power magnetic element primary winding and a secondary winding producing a regulated output using a control technique and circuit to control the magnetic flux reset time of the magnetic element of the power magnetic element. U.S. Pat. No. 5,285,369 (1994) to Balakrishnan discloses a switching power supply that includes a full-wave bridge rectifier to rectify incoming AC line voltage, a transformer having a primary winding and two secondary windings and a switched mode power supply chip that includes an integrated high voltage power MOSFET with a low voltage tap in the drift region. U.S. Pat. No 5,041,956 (1991) to Marinus discloses a switched mode power supply circuit including a controllable switch for controlling the current in the supply transformer of the power supply circuit. U.S. Pat. No. 4,625,271 (1986) to Chetty et al. discloses a soft-start circuit for an inverter having a switch which is operated in accordance with the output of an oscillator and includes a ramp generator coupled to the oscillator for generating a cycle ramp signal synchronized to and having the same period as the oscillator output, the cycle ramp signal also having an amplitude which periodically increases between first and second levels. U.S. Pat. No. 4,541,039 (1985) to Sandler discloses a D-C to D-C forward converter power supply with a magnetic modulator in the timing circuit which operates between its residual magnetic flux density and its saturation flux density to deliver a fixed number of volt seconds during sequential clock interval periods. U.S. Pat. No. 3,824,441 (1974) to Heyman et al. discloses a power supply for providing a plurality of regulated voltage levels while protecting the power supply from damage due to fault conditions.
›Tables in the description — 62
| FIG. 3 , 3A | Table |
| Element | Value/part number |
| C1 | .01 uf |
| C2 | 1.8 uf |
| R2 | 100k ohms |
| D4 | STA1206 Diode |
| R17 | 375k ohms |
| Q1 | IRFP460 |
| C16 | 100 uf |
| C17 | 100 uf |
| R26 | .05 ohms |
| D70 | STA1206 DI |
| Q2 | IRFP460 |
| C4 | 10 uf |
| Q6 | FS14Sm-18 A |
| Q9 | FS14Sm-18 A |
| Element | number |
| C1 | .01 uf |
| C2 | 1.8 uf |
| R2 | 100k ohms |
| R26 | 0.05 ohms |
| Q1 | IRFP 460 |
| D4 | STA1206 DI |
| C17 | 100 uf |
| C16 | 100 uf |
| R17 | 375k ohms |
| Element | number |
| C1 | .01 uf |
| C2 | 1.8 uf |
| R26 | 0.05 ohms |
| Q1 | ATP5014B2LC |
| D4 | STA1206 DI |
| D460-D462 | STA1206 DI |
| C442 | 330 uf |
| C417 | 0.58 uf |
| R345 | 1 MEG ohms |
| Element | Value/part number |
| R20 | 100k ohms |
| D6 | STA1206 DI |
| Q111 | IRFP460 |
| C6 | 10 uf |
| Element | number |
| R20 | 1k ohms |
| R61 | 2k ohms |
| Q21 | TST541 |
| U12 | 4N29 |
| Q11 | IRFP460 |
| C10 | 1.8 uf |
| Element | Value/part number |
| R20 | 5k ohms |
| Q10 | FTZ605CT |
| Q20 | FTZ750CT |
| C10 | 1.8 uf |
| Element | Value/part number |
| R20 | 100k ohms |
| Q116 | IRFP460 |
| D16 | STA1206 DI |
| C16 | 200 uf |
| Element | Value/part number |
| Q31 | IRFP460 |
| D14 | STA1206 DI |
| C14 | 10 uf |
| Element | Value/part number |
| 100 | 55 turns 203 uh |
| 101 | 2 × 77932-A7 |
| 102 | 14 turns |
| 102 | 14 turns |
| Element | Value/part number |
| 100 | 55 turns 230 uh |
| 101 | 2 × 77932-A7 |
| 102 | 14 turns |
| Element | Value/part number |
| 110 | 40 turns 50 uh |
| 107 | 2 × 77932-A7 |
| Element | Value/part number |
| 113 | 77352-A7 |
| 122 | 23 Turns |
| 123 | 23 Turns |
| 112 | 67 uh (55 turns) |
| 114 | 77352-A7 |
| 116 | 67 uh (55 turns) |
| 117 | 77352-A7 |
| 118 | 67 uh (55 turns) |
| Element | Value/part number |
| 106 | 77259-A7 |
| 105 | 10 Turns |
| 104 | 70 Turns |
| Element | Value/part number |
| 136 | 77259-A7 |
| 135 | 10 Turns |
| 134 | 70 Turns |
| Element | Value/part number |
| L1 | 375 uH |
| L2 | 375 uH |
| C61 | 0.01 uF |
| C60 | 0.01 uF |
| A1 | 400 V Spark Gap |
| C1 | 0.1 uF |
| D20 | 1000 V/25 A |
| D21 | 1000 V/25 A |
| D22 | 1000 V/25 A |
| D23 | 1000 V/25 A |
| C2 | 1.8 uf |
| Element | number |
| L64 | 270 uH |
| common mode | |
| H core | |
| bifilar | |
| L63 | 1.0 mH 125 u |
| differential | |
| mode | |
| L62 | 12 mH common |
| mode H core | |
| bifilar | |
| C66 | 0.01 uF |
| C63, C62 | 0.47 uF |
| C61, C61, C64, | 2.2 nf Y-cap |
| C65 | |
| C20 | 0.01 uF |
| D20 | 1000 V/25 A |
| D21 | 1000 V/25 A |
| D22 | 1000 V/25 A |
| D23 | 1000 V/25 A |
| C2 | 1.5 uf |
| Element | Value/part number |
| L3 | 750 uH |
| C61 | 0.01 uF |
| C60 | 0.01 uF |
| A1 | 400 V Spark Gap |
| C1 | 0.1 uF |
| D20 | 1000 V/25 A |
| D21 | 1000 V/25 A |
| D22 | 1000 V/25 A |
| D23 | 1000 V/25 A |
| C2 | 1.8 uf |
| Element | Value/part number |
| D20 | 1000 V/25 A |
| D21 | 1000 V/25 A |
| D22 | 1000 V/25 A |
| D23 | 1000 V/25 A |
| C2 | 1.8 uf |
| Element | Value/part number |
| C311 | 0.1 uf |
| C308 | .01 uf |
| R313 | 15k ohms |
| R316 | 15k ohms |
| C313 | 4700 pf |
| R308 | 25k ohms |
| U1A | MIC38C43 (Micrel) |
| Element | Value/part number |
| Q305 | BCX70KCT |
| R339 | 432k ohms |
| C338 | 0.22 uf |
| C318 | 0.22 uf |
| R314 | 2.2 MEG ohms |
| R315 | 715k ohms |
| C341 | 0.33 uf |
| C342 | 0.01 uf |
| C340 | 0.001 uf |
| R328 | 1 MEG ohms |
| R346 | 7.15k ohms |
| D308 | 10BQ040 |
| R340 | 449k ohms |
| R313 | 22k ohms |
| U1B | MC34262 (Motorola) |
| R341 | 499k ohms |
| Element | Value/part number |
| D80 | 40CTQ150 |
| D90 | 40CTQ150 |
| R21 | 100 ohms |
| C26 | 500 pf |
| C27 | 200 pf |
| C28 | 0.1 uf |
| C29 | 10,000 uf |
| C30 | 10,000 uf |
| C31 | 0.1 uf |
| C32 | 200 pf |
| L30 | 10 uh |
| Element | Value/part number |
| D80 | 40CTQ150 |
| D90 | 40CTQ150 |
| C928 | .01 uf |
| C931 | 10,000 uf |
| Element | Value/part number |
| D40 | 40CTQ150 |
| D41 | 40CTQ150 |
| D42 | 40CTQ150 |
| D43 | 40CTQ150 |
| C928 | .01 uf |
| C931 | 10,000 uf |
| Element | Value/part number |
| C503 | .33 uF |
| C504 | 100 uF |
| D501 | MURS120T3 |
| C505 | .33 uf |
| Q504 | LM7818A |
| C508 | 100 uf |
| C507 | 100 uf |
| D503 | MURS130T3 |
| D502 | MURS120T3 |
| Element | Value/part number |
| C261-C263 | 0.33 uF |
| C260 | 0.1 uF |
| D260 | BZX84C16 |
| D261-262 | MURS120TS |
| C265 | 0.33 uf |
| Q260 | FTZ605CT |
| C266 | 0.01 uF |
| L260 | 1 mh |
| R261 | 100K ohm |
| R262 | 10 ohm |
| C264 | 220 uf |
| Element | Value/part number |
| C603 | .33 uF |
| C604 | 100 uF |
| D601 | MURS12OT3 |
| C605 | .33 uF |
| Q604 | LM7818A |
| C608 | 100 uF |
| C607 | .22 uF |
| R607 | 7.5 ohms |
| D603 | MURS120T3 |
| D602 | MURS120T3 |
| Element | Value/part number |
| THS1 | 67F105 (105C) |
| R711 | 20 ohms |
| R712 | 20 ohms |
| Element | Value/part number |
| C715 | 1000 pf |
| C709 | 33 uF |
| Q702 | NOS355NCT |
| Q703 | FZT705CT |
| R710 | 0 ohms |
| R725 | 22.1k ohms |
| Element | Value/part number |
| R800 | 12 ohms |
| R817 | 1 mohm |
| R818 | 1 mohm |
| C814 | 33 pF |
| C819 | 560 pF |
| D805 | MUR160 |
| Element | Value/part number |
| C51 | 220 pf 100 v |
| C52 | 220 pf 100 v |
| C53 | 220 pf 100 v |
| C54 | 220 pf 100 v |
| C55 | 220 pf 100 v |
| D51 | Schottky 1-2ns 100 v |
| SMBSR1010MSCT | |
| D52 | Schottky 1-2ns 100 v |
| SMBSR1010MSCT | |
| D53 | Schottky 1-2ns 100 v |
| SMBSR1010MSCT | |
| D54 | Schottky 1-2ns 100 v |
| SMBSR1010MSCT | |
| D55 | Schottky 1-2ns 100 v |
| SMBSR1010MSCT |
| Element | Value/part number |
| R821 | 470 pF |
| R310 | 12 ohm |
| Element | Value/part number |
| C820 | 330 pF |
| C821 | 330 pF |
| R810 | 12 ohm |
| R811 | 12 ohm |
| Element | Value/part number |
| C840 | 500 pF |
| C841 | 500 pF |
| R820 | 12 ohm |
| R821 | 12 ohm |
| Element | Value/part number |
| R404 | 50k ohms |
| C406 | 100 uf |
| C401 | 0.22 uF |
| C403 | 0.01 uF |
| C405 | 2200 pF |
| C404 | 470 pF |
| C402 | 0.22 uF |
| R403 | 50k ohms |
| D401 | RLS139 (low leakage) |
| R401 | 2.2 MEG ohms |
| R402 | 150k ohms |
| U400 | MIC38C43 |
| Element | Value/part number |
| Q514 | LM7818 |
| C515 | 0.1 uF |
| C517 | 0.1 uF |
| C514 | 10 uF |
| C518 | 10 uF |
| Element | Value/part number |
| C68 | 250 uf |
| D68 | MUR820 |
| Q31 | IRF540N |
| Element | Value/part number |
| C46 | 250 uf |
| D46 | MUR820 |
| Q141 | IRF540N |
| Element | Value/part number |
| C6 | 250 uf |
| D6 | MUR820 |
| Q111 | IRFP |
| Element | Value/part number |
| U903 | NEC2501 |
| Q915 | FZT705CT |
| D903 | ML5248B (18 v) |
| D928 | 1SMB5956BT3 (200 v) |
| R926 | 20k ohms |
| R927 | 10k ohms |
| R928 | 10k ohms |
| R929 | 10k ohms |
| R930 | 20k ohms |
| Element | Value/part number |
| R1123 | 499k ohms |
| R1124 | 499k ohms |
| R1122 | 6.65k ohms |
| R1121 | 499k ohms |
| R1120 | 1 MEG ohms |
| Element | Value/part number |
| U900 | NEC2501 |
| Q900 | FZT705CT |
| D900 | IN5261BDICT |
| R900 | 1k ohms |
| R902 | 4k ohms |
| R901 | 40k ohms |
| Element | Value/part number |
| U905 | NEC2501 |
| Q914 | FZT705CT |
| R938 | 160k ohms |
| R939 | 70k ohms |
| D911 | 1N5261BOTCT |
| R940 | 50k ohms |
| R917 | 40k ohms |
| Element | Value/part number |
| R1123, | 499k ohms |
| R1124 | |
| R1122 | 1.00k ohms |
| R1121 | 1.00k ohms |
| R1123 | 66.5k ohms |
| R1120 | 6.65k ohms |
| Element | Value/part number |
| R81 | 1k ohms |
| D80 | Zener Voltage = (Desired Output − 0.65 V) |
| Q80 | BCX70KCT |
| C80 | 1000 pf |
| R82 | 1k ohms |
| R83 | 715k ohms |
| Element | Value/part number |
| R414 | 22k ohms |
| D410 | BZX84C10 |
| Q413-Q414 | FMMT2222ACT |
| R418 | 25.5K ohms |
| R410, R419 | 499k ohms |
| Element | Value/part number |
| SCR1200 | MCR265-10 |
| D1203 | BZT03-C200 (200 V) |
| D1202 | BZT03-C200 (200 V) |
| D1200 | IN4753 (5.1 v) |
| C1200 | 220 pf |
| R1200 | 10,0k ohms |
| Element | Value/part number |
| SCR1101 | S101E (Teccor) |
| SCR1100 | S601E (Teccor) |
| D1103 | BZT03-C200 (200 V) |
| D1102 | BZT03-C200 (200 V) |
| D1100 | IN4753 (5.1 v) |
| R1100 | 16000 |
| R1101 | 5.1K ohms |
| R1102 | 5.1K ohms |
| C1100 | 1200 pf |
| C1101 | 1200 pf |
| Element | Value/part number |
| D970 | 1N5261BOTCT |
| U970 | NEC2501 |
| Q970 | FZT705CT |
| R970 | 160k ohms |
| R971 | 10k ohms |
| R972 | 22k ohms |
| C970 | 200 pf |
| Element | Value/part number |
| D980 | 1N5261BOTCT |
| SCR980, SCR981 | S601E (Teccor) |
| U980 | NEC2501 |
| Q980 | FZT705CT |
| R980 | 160k ohms |
| R981 | 10k ohms |
| R982 | 22k ohms |
| R983 | 51k ohms |
| R984 | 1200 ohms |
| R985 | 510 ohms |
| C980 | 200 pf |
| C981 | 1200 pf |
| C982 | 1200 pf |
| Element | Value/part number |
| U14 | MC33025 |
| R126 | 12k ohms |
| R130 | 10 ohms |
| R131 | 10 ohms |
| R132 | 47k ohms |
| R133 | 10k ohms |
| R134 | 100k ohms |
| R135 | 15k ohms |
| R136 | 1.5 MEG ohms |
| R137 | 15k ohms |
| R138 | 10K ohms |
| C136 | 0.22 uf |
| C139 | 0.22 uf |
| C140 | 0.22 uf |
| C141 | 0.01 uf |
| C142 | 0.001 uf |
| C143 | .33 uf |
| Element | Value/part number |
| D447 | 1N5246 |
| R441, R442 | 300K Ohm |
| R443-445 | 100 Ohm |
| C448 | 0.33 uF |
| C442 | 330 uF 450 V |
| C449 | 0.1 uF |
| R446 | 4.7 MEG Ohm |
| Element | Value/part number |
| D451 | Rlz5.1 ZENER 5.1 v |
| D452 | Rlz24 ZENER 24 v |
| R451 | 1 MEG Ohm |
| R452-453, | 2.2 MEG Ohm |
| R454 | |
| R455 | 4.3K Ohm |
| R456 | 499K Ohm |
| C453 | 0.01 uF |
| C451 | 4.7 uF |
| C452 | 1.0 uF |
| Q450 | FMMT2222 |
| Q451 | STD3NC80 |
| Element | value/part number |
| D460-D462 | S3M 3 amp/1000 v |
| C260 | 330 ufd 450 V |
| 461 | Bridge 15 Amp/800 V |
| C2 | 1.5 ufd 630 v |
| C262 | 2.2 ufd 630 v |
| Element | Value/part number |
| R458 | 1 MEG ohm |
| C468 | 220 ufd 450 V |
| BR468 | 35 Amp/600 V |
| Element | Value/part number |
| U5800 | LTC4562 |
| R5801 | 383K ohm |
| R5802 | 5.6k ohm |
| R5803 | 750k ohm |
| R5804 | 34.0k ohm |
| R5805 | 0.002 ohm |
| R5806 | 2.8k ohms |
| R5807 | 1.0 MEG ohms |
| R5808 | 10.0 ohm |
| C5809 | 0.01 uf/50 v |
| C5810 | 2.2 uf/50 v |
| C5811 | 0.22 uf/50 v |
| C5812 | 0.018 uf/50 v |
| C5813 | 0.33 uf/50 v |
| Q5814 | 0.008 ohm 80 V Nch FET |
| R5815 | 7.15K ohm |
| U5816 | PS 2701 opto |
| Element | Value/part number |
| BR6019 | Bridge Rectifier 600 V/100 ma |
| U6017B, | LM2903 |
| U6018A | |
| R6000 | 174k ohm |
| R6001 | 174K ohm |
| R6002 | 200K ohm |
| R6003 | 19.6k ohm |
| R6004 | 20.0k ohm |
| R6005 | 6.34k ohm |
| R6006 | 475k ohms |
| R6007 | 10.0k ohms |
| R6008 | 1.10k ohm |
| R6009 | 162K ohm |
| R6010 | 10.0K ohm |
| R6011 | 10.0k ohm |
| R6012 | 39.2k ohm |
| R6013 | 10.0k ohm |
| C6014 | 0.33 uf/50 v |
| C6015 | 0.1 uf/50 v |
| D6016 | RLS139 40 v 100 ma |
| Element | Value/part number |
| 6100 | 93 uh |
| 6101 | 2 × 77932-A7 |
| 6102 | 1 turn |
| Element | Value/part number |
| C6634, | 100 ufd |
| C6631 | |
| C6630 | 0.22 ufd |
| D6633 | Zener 18 V |
| D6637-D6638 | MURS120TS |
| Q6631 | FTZ605CT |
| L6636 | 1 mh |
| R6632 | 100K ohm |
| R6635 | 10 ohm |
| C504 | 220 uf |
| Element | Value/part number |
| D6701 | SIC Schottky 600 v/1 A |
| UPSC600 |
| Element | Value/part number |
| R6801 | 1.86 MEG ohms |
| R6802 | 100k ohms |
| Element | Value/part number |
| U6900 | MC33025 |
| R6902 | 12k ohms |
| R6901 | 100k ohms |
| R6903 | 1.5 MEG ohms |
| C6906 | 0.22uf |
| C6904 | 0.01uf |
| C6905 | 0.001uf |
| Element | Value/part number |
| C7000 | 5000pF |
| R7001 | 750K ohm |
| D7002 | US1M |
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- H02M1/00
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