| 摘要 |
PROBLEM TO BE SOLVED: To reduce the unidentified period of a microcomputer 35 in a power source circuit 10 for an electric appliance using a transformer 11 of a small capacity for reducing power consumption. SOLUTION: A switch circuit 40 is interposed between a DC constant voltage circuit 24 and the power source terminal of the microcomputer 35 and can be switched to be conductive or non-conductive. A CR including circuit 49 has a capacitor 53 charged by the rectified current of the secondary AC current of the secondary coil 13 of the transformer 11, and controls the circuit 40 to be conductive or non-conductive by switching on/off of the NPN type transistor 44 of the circuit 40 by the voltage of the capacitor 53. Thus, an electrolytic capacitor 21 boosts voltage sufficiently in the non-conductive period of the circuit 40 and is made to load the microcomputer 35 with conducting of the circuit 40 after then.
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