| 摘要 |
PURPOSE:To keep DC voltage at a fixed value even at occurrance of an instantanous power failure by providing it with a rectifier, a boosting chopper, which is connected in the same polarity between first smoothing capacitor and a second smoothing capacitor and starts instantaneously, and a diode, which lets an accumulated current flow to the smoothing capacitor. CONSTITUTION:In an instantaneous power failure condition where the terminal voltage V1 of a second smoothing capacitor 11 is smaller than the terminal voltage V0 of a first smoothing capacitor V0 (V1<V0), energy is supplied to load L by the course of a second rectifier 12 a boosting chopper 4 the first smoothing capacitor 2 an inverter 3. The control of the boosting chooper 4 at this time is performed by the detection voltage of PT9, the detection voltage detector 10, and the output signal of a chopper control circuit 8. Hereby, even in an instantaneous power failure, the operation of the inverter can be continued. |
