| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharging circuit which can discharge a smoothing capacitor speedily when power supply is interrupted. SOLUTION: A capacitor C1 is provided between an input line ACL1, which is connected between diodes D1 and D2, and an output line DCL1. When an AC power supply E1 supplying AC voltage between the input lines ACL1 and ACL2 stops, it can prevent a current from flowing from a smoothing capacitor C2 to a capacitor C1, therefore it can accelerate the speedy discharge of the capacitor C1. When a voltage across the capacitor C1 drops under a specified value, a switch control circuit 11 switches on the switch element SW1 so as to discharge smoothing capacitors C2 and C3, therefore it can speedily discharge the smoothing capacitor. COPYRIGHT: (C)2009,JPO&INPIT
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