This circuit turns your air conditioner or other appliance on and off in adjustable cycles to save energy. The circuit is from a 1983 Electronics Experimenter Handbook Special projects.
We found this circuit in a 1995 publication. It makes use of infrared LEDs of the type existing at...
Relays up to 100 mA can be driven by the 555 with the recommended circuit. The circuit is from an...
The sensor for this circuit is a phototransistor. We found it in the April 1971 issue of Radio...