| 摘要 |
[Summary] [Object] To suppress occurrence of a problem upon power return from instantaneously power failure. [Means for Settlement] When electric power of an AC power source (100) returns in a state in which accumulated electric charges of a smoothening capacitor (11) are still left, an output voltage VDC of an AC-DC conversion part (1) rises. At this time, a signal output part (40) of a control part (4) turns off a switching element (30) by a stop signal provided from a forced OFF control part (6), and thus an output voltage Vo of a DC-DC conversion part (2) does not raise. Therefore, the output voltage VDC of the AC-DC conversion part (1) continues to rise without being clumped at a low voltage. As a result, occurrence of a problem upon power return from instantaneously power failure can be suppressed. |
