| 摘要 |
PURPOSE:To prevent the fluctuation of a negative polarity voltage, by detecting the fluctuation of an output voltage and controlling a positive polarity voltage with negative feedback, in a circuit outputting a negative polarity power supply through the rectification of an output of an oscillation circuit applied with the positive polarity power supply. CONSTITUTION:An output of an oscillation circuit 30 consisting of logical ICs 6-8 and feedback circuits 1-5 and to a terminal 20 of which a positive polarity voltage is supplied is rectified at a rectification circuit 31 and a negative pollarity voltage is outputted t a terminal 31. The output of the circuit 31 is connected to a positive polarity power supply 19 via a series connection of resistors 16 and 17, and the connecting point of the resistors 16 and 17 is connected to the base of a transistor (TR) 18. The collector of the TR18 is connected to the power supply 19 and the emitter is connected to the terminal 20. If an output voltage at a terminal 31 changes to positive direction, the base of the TR18 also charges to the positive direction, the voltage at the power supply terminal 20 of the circuit 30 changes to the positive direction, a voltage at the terminal 31 changes to negtive polarity and the fluctuation in the negative polarity voltage can be suppressed. Similarly, the fluctuation in the negative polarity voltage output can be suppressed in case of opposite change. |
