| 摘要 |
PURPOSE:To feed the charging voltage of the capacitor of an energy-storing circuit to a constant-voltage power supply from the energy-storing circuit at the time of detection of a momentary break by providing the energy-storing circuit on the output side of a rectifier circuit in a feeder circuit being of a line operator type for feeding DC voltage from a commercial power supply to the constant-voltage power supply and equipped with an active smoothing filter function. CONSTITUTION:An energy-storing circuit 40 is connected between a rectifier circuit 20 and active smoothing filter circuit 30 and an energy-storing capacitor 41 is charged with electricity to the peak value of rectified voltage Vr. When service interruption is detected by a momentary-break detection circuit 50, the energy-storing circuit 40 receives the detection signal DS of the circuit 50 and immediately turns ON a transistor switch 43 to supply a constant-voltage power supply 10 with the charging voltage of the capacitor 41. Thus, it is possible to normally charge the capacitor 41 without affecting the operation of the active smoothing filter circuit 30, to prevent the interruption of operation of the constant-voltage power supply 10 at the time of a momentary break and to reduce the static capacity of the capacitor 41. |
