| 摘要 |
PROBLEM TO BE SOLVED: To stop the operation of a switching power supply when abnormal temperature is detected and thereafter keep the power supply from returning. SOLUTION: Main input terminals 10 are connected with a rectifier 16 and an input smoothing capacitor 17 for rectifying and smoothing alternating current with a fuse element 15 in-between. A control circuit 18 has a switching signal control circuit 31 including an oscillator, an overheat protection circuit 32, and a zap circuit 33 which stops the operation of a switching element 12 according to signals from the overheat protection circuit 32. The zap circuit 33 includes a power supply terminal VCC connected with a control terminal TC, an input terminal IN connected with the inverting output terminal of the RS flip flop circuit 32c of the overheat protection circuit 32, and an output terminal OUT connected with one input terminal of a NAND circuit 34. COPYRIGHT: (C)2003,JPO
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