| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive, stable, and compact power supply circuit for a crystal liquid display device. SOLUTION: This power supply circuit is equipped with a reference voltage circuit 8, a voltage adjustment circuit 9, a switch circuit 10, and a stabilization circuit 11. The voltage circuit 8 supplies a liquid crystal device drive means (not shown) with a reference voltage for driving a liquid crystal display device 6 composed of resistors and connected to a microcomputer 7. The adjustment circuit 9 is composed of resistors, used for receiving an input voltage from a first power supply circuit 4 to adjust an output voltage of the supply circuit 4 so that it remains substantially equal when it is output as a first voltage while a commercial AC power supply is turned on and when it is output as a second voltage while the power supply is turned off, and outputting the output voltage to the voltage circuit 8. The switch circuit 10 is used for receiving an output of a second power supply circuit 5 to turn on/off the adjustment means 9. The stabilization circuit 11 is composed of resistors and capacitors to stabilize the voltage input to the voltage circuit 8 when the output voltage of the supply circuit 4 is switched between the first and second voltages. COPYRIGHT: (C)2009,JPO&INPIT
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