| 摘要 |
PURPOSE:To enable to reduce the rated voltage of a starting thyristor by adding a discharging resistor which is reduced in the resistance value as compared with a charging resistor and a diode. CONSTITUTION:A diode 4h is added to a starter 4, and a charging resistor 4d is selected to a small value by a discharging resistor 4k. An energy stored in starting resistor 4e is supplied to a parallel resonance load 5 by firing a starting thyristor 4f after an auxiliary power switch 4a is closed to complete charging, and the capacitor 4e is charged in opposite polarity. Then, it is abruptly discharged through a diode 4h and the discharging resistor 4k to quickly eliminate the voltage. Thus, the discharging time of the starting capacitor can be shortened, thereby reducing the rated voltage of the starting thyristor. |
