| 摘要 |
PURPOSE:To enable to perform stable operation of a chopper without fail of commutation by delaying the time to the release of the interruption of the gate for restarting the chopper after the input voltage is recovered to a value higher than the set value. CONSTITUTION:When the input voltage of a chopper circuit 4 recovers to a value larger than the set value, the output of a comparator 25 becomes ''H'' level, an input signal is again transmitted to a timer circuit 26, which provides the prescribed delay time, and then outputs a gate open or close signal to a logic circuit 21. In this manner, the gate signal for the interruption of the thyristor can be eliminated, the commutation condenser 10 of the chopper 4 is recovered to the charging level to the input voltage value during the time delay of the timer 26. Thus, when the interruption of the gate signal is eliminated, the chopper 4 again starts operating. |
