| 摘要 |
<p>PURPOSE:To miniaturize the reset control circuit to incorporate it in a device circuit by outputting a detection signal from a comparing circuit to output various control signals from a relay circuit at the time when the rise voltage of a time constant circuit reaches a prescribed value. CONSTITUTION:When a power source is turned on, a capacitor C is charged through a resistance R1. When the potential of the positive electrode of the capacitor, namely, the negative input of an operational amplifier OP reaches a prescribed voltage RV, the amplifier OP outputs the signal indicting that the rise voltage of a main power source MV reaches the prescribed voltage RV. A transistor Q energizes a relay circuit 19 in accordance with the output of the operational amplifier OP, and each contact output RS of the circuit 19 goes to a state corresponding to energization. When the main power source MV is turned off, the potential of the positive electrode of the capacitor C, namely, the negative input of the amplifier OP is reduced, and the amplifier OP detects turning-off of the power source by the fall to the voltage RV or lower to output the detection output. The transistor Q is turned off in accordance with the output of the amplifier OP to disenergize the circuit. Thus, the state of the output RS is switched.</p> |
