Amplifier Auto off Timer Circuit

Amplifier Auto off Timer Circuit
This circuit turns off the power, or any other device when the input signal is absent for more than 15 minutes. Pressing the P1 circuit is switched on and supplies power to any device connected to the outlet SK1. The input signal is amplified and limited by IC2A and IC2B, and controlled light-emitting diode D4. In the flash of the LED D4, even very short, chip IC3 is reset and restarts its counting. At the conclusion 2 IC3 remains