This circuit was originally suggested in a 1968 publication to generate a white mark (frame) on a film at regular intervals to serve as a time reference.
We found this circuit in the August 1994 issue of Electronics Now magazine. The circuit is based on...
This circuit from a Radio Electronics from February 1966 uses an LDR as a sensor. The transistor is a...
Originally, this circuit was created to monitor the liquid level in the reservoir of a car's...