ON/OFF Sleep Timer Switch Circuit

This timer was designed mainly to switch off a portable radio after some time: in this way, one can fall asleep on the sand or on a hammock, resting assured that the receiver will switch off automatically after some time, saving battery costs.ON/OFF Sleep Timer Switch CircuitR1 and C1 provide a very long time constant. When P2 is momentarily closed, C1 discharges and the near zero voltage at its