Embodiments in accordance with the present invention provide circuits and methods for driving a light-emitting diode (LED) light source. In one embodiment, a printed circuit board (PCB) includes a bridge rectifier rectifying an AC voltage to a rectified AC voltage, an LED light source, and a first switch coupled to the LED light source in series controlling a current through the LED light source according to a predetermined current reference. The LED light source and the first switch coupled in series receive the rectified AC voltage while the first switch is controlled linearly. The circuit further includes a current path coupled in parallel with the LED light source and an illuminated switch coupled between the AC power source and the bridge rectifier.

Claims

11 · 1 independent · depth 3

11 granted claims

›1.independentA printed circuit board (PCB) comprising:na bridge rectifier for rectifying an AC voltage to a rectified AC voltage;a light-emitting diode (LED) light…+10

›2.↳ 1The PCB of claim 1, further comprising:ncontrol circuitry coupled to said first switch and for controlling said first switch linearly by comparing a s…d2+3

›6.↳ 1The PCB of claim 1, wherein said DC voltage represents a forward voltage of said LED light source.d2

›7.↳ 1The PCB of claim 1, wherein said DC voltage is proportional to an average level of said rectified AC voltage.d2

›8.↳ 1The PCB of claim 1, wherein said rectified AC voltage comprises a periodic voltage signal.d2

›9.↳ 1The PCB of claim 1, wherein said rectified AC voltage comprises a half-wave sinusoidal voltage signal.d2

›10.↳ 1The PCB of claim 1, wherein said LED light source comprises a plurality of LEDs coupled in series.d2

›11.↳ 1The PCB of claim 1, wherein said current path comprises a resistor.d2

Classifications

4 codes

IPC · International Patent Classification

Section H — Electricity

H05B37/02

USPC · US Patent Classification

315/291315/308315/209.R

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Pendency

1.3 y

460 days filing → grant

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non-final + final

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2 RCE

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Thuy Vinh Tran

art unit 2821 · TC 2800

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Citations: 12 back · 0 forward

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1 priority documents

›Priority documents — 1

Type	Document	Date
related publication	US 20110221346 A1	15 Sep 2011

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