| 摘要 |
PROBLEM TO BE SOLVED: To allow control with an external remote control signal only with a photocoupler for internal control. SOLUTION: The switching power supply is provided with unstable multi-vibrator 13 that operates with a remote control signal which is externally inputted in remote control terminals 12a and 12b as a power source voltage, a rectifying/smoothing circuit 14 for remote control which rectifies/smoothes an output of the unstable multi-vibrator 13 and flows a signal current corresponding to the remote control signal to a light-emitting diode 10 of a photocoupler 9. In the unstable multi-vibrator 13, each collector of a transistor which is controlled to be on and off alternately is connected to the remote control rectifying/smoothing circuit 14. In the remote control rectifying/smoothing circuit 14, each collector of the transistor is connected, for inputting, to a rectifying/smoothing part through a capacitor, while the rectifying/smoothing part is connected in parallel to the light-emitting diode 10 through a reverse current preventing diode. COPYRIGHT: (C)2005,JPO&NCIPI
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