| 摘要 |
<p>A switching circuit which can be easily turned off and forcibly maintained in that state, and which has a self-holding function and a self-arc-extinguishing function. For instance, when it is detected by voltage detecting means (comparator 3) that a voltage across the base and the emitter of a bipolar transistor (7) is greater than a predetermined value, switching means (transistor 6) operated (via a transistor 5) according to the voltage detecting means connects the collector and the base of said bipolar transistor (7) together.</p> |
