Timed photocell switch circuit

摘要

A timed photocell switching circuit is disclosed which senses a light-to-dark transition and applies power to a lamp load for a preset period of time. After the preset period has expired the timed photocell circuit turns the lamp load off for the remainder of the night until a dark-to-light transition resets the circuit after which it can be triggered for another timing cycle. Once the light-to-dark transition triggers the timing cycle the ambient light level cannot disrupt the circuit. In addition, the circuit can be reset regardless of its timing position by momentarily cycling power to the circuit.