| 摘要 |
PURPOSE:To detect the arm short-circuit of the titled device in a short period by monitoring the period wherein the fluctuating DC input current is brought to the intensity of a fixed level or above. CONSTITUTION:The DC input current is detected by a DC input current detecting device 15 as a voltage. This voltage and the reference voltage inside an arm short-circuit detecting circuit are compared by a comparator 17. Ordinarily, as the time constant of a timer 18 is larger than the maximum value of the period of L-level of the comparator 17, the output of the timer circuit 18 is always maintained at H-level. When an arm stort-circuit is generated, the output of said timer circuit 18 is turned to L-level, and an R-S flip-flop 19 is set. |
