| 摘要 |
<p>PURPOSE:To enhance safety by turning a short circuit switch ON/OFF at the stage of starting a motor in order to regulate the starting current, detecting the current at the main circuit section upon elapse of a predetermined time after turn OFF of a main switch, and then turning a trip contact ON/OFF based on a detection signal. CONSTITUTION:When a main switch 12 is turned ON, a rush current flows into a DC series motor 15. The rush current is regulated by turning short circuit switches 14a-14c ON/OFF. A Hall element 16 detects the current of a main circuit and delivers a signal to a detecting circuit 18. The detecting circuit 18 actuates a trip interrupter 17 based on the detection signal and turns a trip contact 17b OFF thus interrupting the current of main circuit. At the same time, a protective circuit section 19 is formed and an alarm is presented thus enhancing the safety.</p> |
