| 摘要 |
PROBLEM TO BE SOLVED: To provide a separately excited switching regulator for carrying out intermittent oscillation forcibly in a simple circuital constitution. SOLUTION: In a separately excited switching regulator 1, a switch 22 is turned off by a given standby signal during standby, and a full-wave rectified voltage of a commercial AC is fed from a rectifying circuit 18 to resistors 19 and 20. The voltage is divided by the resistors 19 and 20 and a switching element 17 is turned on when a voltage across terminals of resistor 20 becomes over a Zener voltage of a Zener diode 20. Through the turn-on and -off of the switching element 17, a collector voltage of the switching element 17 (terminal voltage of resistor 26) as an input voltage of a control circuit 10 becomes rectangular pulse with a frequency that is double the commercial AC frequency. When the voltage signal is fed to the control circuit 10, the control circuit 10 causes oscillation by turn-on and -off by the switching element 9 intermittently to drop an output of the separately excited switching regulator 1 into standby power.
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