This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut off. We found it in the Encyclopedia of Electronic Circuits Volume 5 of 1995.
This circuit was found in the July 1992 issue of Radio Electronics magazine. The circuit is based...
This circuit was found in Electronics Today International of the 80's. The circuit uses still...
This circuit is from the National Semiconductor FET Databook. The coil data is provided with the...