| 摘要 |
PURPOSE:To prevent the breakdown of an element in a double-voltage circuit and prevent the coalescence phenomenon of a switch by detecting the zero cross of the outputted AC current and turning on the switching element controlling the feed of the AC current to the double-voltage circuit with the zero cross timing of the AC current. CONSTITUTION:A power source section 1 outputting the AC current, a signal generating section detecting the zero cross of the outputted AC current and generating the zero cross signal, switching elements SCR1 and SCR2 controlling the feed of the AC current to a double-voltage circuit 12, and a controller detecting the zero cross signal and turning on the switching elements with the timing of the zero cross of the AC current are provided. No large current flows into the double-voltage circuit 12 when the feed of the AC current to the double-voltage circuit 12 is started, elements including the switching elements in the double-voltage circuit are not broken, no chattering occurs, the coalescence phenomenon of a switch does not occur. |
