| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a DC power switch preventing a large rush current from a DC power supply to a load apparatus and power back-flow from the load apparatus to the DC power supply. <P>SOLUTION: First, a switch S2 is turned off so as to finish feeding. Charges accumulated in a capacitor C1 are discharged at a resistor R1 and the bias voltage of a transistor Q1 generated on the both ends of the resistor R1 begins to step down. The value of current via the transistor Q1 is gradually decreased. Finally, the transistor Q1 is put in an OFF state, and the switch S1 is concurrently turned off. Gradual reduction in power supply does not cause high counter-electromotive force at the load device 2, thereby preventing power back-flow to the DC power supply 1. <P>COPYRIGHT: (C)2009,JPO&INPIT |
