| 摘要 |
<p>PURPOSE:To reduce the power consumption in a switch by limiting the current flowing through the switch by turning off a control transistor so as to set a current limiting resistance to a non-short-circuited state when the switch is closed from an opened state. CONSTITUTION:While a switch 1 is in an opened state, the state of the switch is repeatedly detected until the switch 1 is closed. When the switch 1 is closed in such a condition, a detecting signal '0' is outputted from a control circuit 5 and the signal '0' is statically latched by a latch circuit 8. In other words, the circuit 8 is reset. Accordingly, a control transistor 11 is turned off and an electric current which is limited by a series resistance of a resistance 2 and current limiting resistance 7 flows to the switch 1 after the lapse of time (t) from the time the switch 1 is closed. Therefore, the power consumption in the switch 1 can be reduced while the switch 1 is closed.</p> |
