| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching AC adapter circuit having simple circuitry. SOLUTION: A photocoupler control circuit (28) provided in the secondary circuit and connected with a constant voltage control circuit (22), an overcurrent detection circuit (24) and an overvoltage detection circuit (26) controls a photocoupler (IC1) such that a constant voltage detection control signal is fed back to the primary circuit as a feedback signal. Upon receiving at least one of an overcurrent detection signal and an overvoltage detection signal, the photocoupler control circuit (28) controls the photocoupler (IC1) to be turned off. Upon detecting a voltage induced in the auxiliary winding (NSLD) of a transformer (T1) when the photocoupler is turned off, a voltage detection circuit (18) actuates a latch circuit (16) thus stopping switching operation of the switching AC adapter circuit. COPYRIGHT: (C)2005,JPO&NCIPI
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