| 摘要 |
PURPOSE:To prevent a large rush current at the time of supplying a current by supplying a current to a secondary winding of a transformer through a diode when a power source is turned ON and switching elements of a half-wave switch circuit are alternately switched to be operated, and charging a smoothing capacitor by the current. CONSTITUTION:Switching elements 25, 28 of half-wave switch circuits 27, 30 are alternately controlled to be turned ON, OFF in a high frequency by driving means. First, second diodes 26, 29 are connected at anodes to a negative terminal of a smoothing capacitor 31. When an AC power source 21 is turned ON, a capacitor 23 is charged through a full-wave rectifier 21. However, the capacitor 23 absorbs a high frequency oscillation voltage, and has a sufficiently small capacity for a low frequency of the power source 21. Thus, a rush current when the power source is turned ON is very small. That is, flow of a large rush current can be prevented. |
