| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive voltage polarity inverter, which generates voltages having polarity opposite to the power voltage with reduced disturbances by using the AC voltage which drives a cell signal as a drive voltage signal or the clock signal voltage. SOLUTION: A coil L is connected between a drain terminal D of a field effect transistor T and an input terminal E1, where an operating voltage V+ (e.g. +3V) is applied. The source terminal of the TR T is connected to a fixed reference potential P (e.g. ground), and a gate terminal G of the TR T is connected to an input terminal E2, where a supply signal voltage VCLK (e.g. square waveform of +3V) of a call signal generator is applied via a current limit resistance R1 and a coupling capacitor C3. Then the terminal D is connected to a negative polarity double voltage rectifier circuit, consisting of capacitors C1 and C2 and diodes D1 and D2 and outputs a negative voltage V- (e.g. -6V to -9V) to a circuit output terminal A. The voltage polarity inverter of such a constitution requires no additional oscillator and accordingly has especially reduced disturbances. |
