| 摘要 |
PURPOSE: To prevent the safety of an apparatus from lowering by reducing large rush current through connection of a current limiting resistor between main electrodes and a second triac, being turned on with a predetermined time lag behind a first triac, in series with the first triac. CONSTITUTION: Upon elapse of a predetermined time after an AC voltage is applied to a surge current suppression circuit 1 and first triac H1 is turned on, a delay circuit begins to supply a DC voltage to a second phototriac coupler 7. Consequently, the second phototriac coupler 7 begin to function and a second triac H2 is triggered at a zero-cross point of AC voltage immediately after staring the operation thus turning the second triac H2 on. Consequently, a current path for bypassing a current limit resistor R4 is established and the input and output terminals 2a-3a, 2b-3b of the surge current suppression circuit 1 are closed through no resistance thus preventing the current from lowing continuously into the current limit resistor R4 in the surge current suppression circuit 1. |
