| 摘要 |
PURPOSE:To facilitate the trouble shooting by memorizing the output waveforms and monitored waveforms of the gate pulses before and after the occurrence of failures in thyristors, and reproducing the waveforms as digital signals after the failures have occurred. CONSTITUTION:The output waveforms of the inverter circuit or the waveforms of the gate pulses in each thyristor are converted into the signal of a digital level in a level converting circuit 5, and the signal is supplied to a shift register circuit 6 via a shift register input signal switching circuit 7. At the normal operation, the switchig circuit 7 is in the position where the signal from the level converting circuit 5 is memorized in the shift register 6. When the failure has occurred, the switching circuit is switched and the output signal from the shift register 6 is fed back to become the input signal to the shift register 6 again. Therefore, the monitored data before the occurrence of the failure can be reproduced by a synchroscope and the like, thereby the monitoring performance can be enhanced. |
