Control system for a humidifier

This invention relates to a control system for a humidifier, particularly to one having a variable resistor with an on/off switch function for turning on and off a supersonic oscillator so as to lower the cost of a humidifier.

A known conventional control system for a humidifier shown in FIGS. 1 and 2, includes an AC input terminal, an interactive switch SW consisting of a variable resistor VR and a silver contact point, a neon lamp L and an AC fan F for heat dispersing connected in parallel to the interactive switch SW, a transformer T for lowering the voltage, a bridge rectifier B 1 for changing AC into DC, two resistors R 1 , R 2 connected in parallel to the input and the output 1 and 2 of the bridge rectifier B 1 , a contact point 3 between the two resistors R 1 , R 2 connected to one end of the variable resistor VR, two inductance coils L 1 , L 2 and the base of a transistor Q 1 connected in series to the variable resistor VR. Further, an ultrasonic oscillator circuit provided between the inductance coil L 1 and L 2 and consisting of a capacitor C 1 and an ultrasonic oscillator H., and a capacitor C 2 connected between the capacitor C 1 and the ultrasonic oscillator H to divide current. Then the emitter 5 of the transistor Q 1 is connected to another inductance coil L 3 , and a diode D 1 is connected between the emitter 5 and the inductance coil L 3 to divide the current, and a capacitor C 3 is connected to the end of the circuit of the control system.

The known conventional control system for a humidifier consists the switch SW and the silver contact point to function as a general switch for the control system for a humidifier. So the conventional control system for a humidifier has a disadvantage of high cost.

The objective of the invention is to offer a control system for a humidifier of a lower cost than that of the conventional ones.

One feature of the invention is a variable resistor used in the control system also having on/off function, enabling the control system more quickly operated.

Another feature of the invention is a DC fan used instead of an AC fan for dispersing heat to lower the cost of the control system.

This invention will be better understood by referring to the accompanying drawings, wherein:

FIG. 1 is a diagram of a known conventional control system for a humidifier;

FIG. 2 is a perspective view of a variable resistor in the known conventional control system for a humidifier;

FIG. 3 is a diagram of a control system for a humidifier in the present invention; and,

FIG. 4 is a perspective view of a variable resistor in the control system for a humidifier in the present invention.

A preferred embodiment of a control system for a humidifier in the present invention, as shown in FIG. 3, includes an AC input terminal AC, a transformer T for lowering AC voltage, a bridge rectifier B connected to the transformer T to change AC into stabilized DC, first and second resistors R 1 and R 2 connected in parallel to first and second terminals 1 and 2 of the bridge rectifier B, a variable resistor VR having third terminal 3 connected between the first and second resistors R 1 , R 2 to permit a carbon ring A shortened in advance to form a blank A 1 to let the variable resistor VR function as an on/off switch SW. Then a power lamp LED, a third resistor R 3 and a first transistor Q 1 for current dividing are connected to fourth terminal 4 of the variable resistor VR. The emitter of the first transistor Q 1 is connected to one end of an second inductance coil L 2 , and the collector of the first transistor Q 1 is connected to one terminal of a DC fan. Further, the fourth terminal 4 is also connected to a current dividing circuit formed of an first inductance coil L 1 , a fifth resistor 5 , and a second transistor Q 2 . A fifth terminal 5 between the first inductance coil L 1 and the fifth resistor R 5 is connected to a current diving circuit formed of a capacitor 1 and a supersonic oscillator H. Then a current dividing circuit formed between the supersonic oscillator H and the first capacitor C 1 is connected to a second capacitor 2 . Then the fifth resistor 5 is connected to the base of the second transistor Q 2 , and the sixth terminal 6 of emitter of second transistor Q 2 is connected to an third inductance coil L 3 and also connected to a diode D. Then a second capacitor 2 is connected to the end of the circuit.

When the variable resistance VR is adjusted to have a resistance value and also turns on the power, the power lamp LED is lit up, with the first and second transistors Q 1 and Q 2 turned on to start the supersonic oscillator H. When the variable resistor VR is adjusted to the blank space A 1 of the carbon ring A and turns off the power, the power lamp LED is turned off, with the supersonic oscillator H also turned off. Thus the variable resistor VR has function as an on/off switch. In addition, the DC fan can reduce some cost of a humidifier as well.

While the preferred embodiment of the invention has been described above, it will be recognize and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.