This circuit was found in a Popular Electronics from the 80s. It is possible to control a relay from a video signal. The circuit was used in video recorders of the time.
The frequency of the signal produced by this oscillator depends on the amount of light falling...
The circuit presented is based on a mechanical tuning fork. The circuit is suggested by National...
This is a well-known RC oscillator configuration using a 741 operational amplifier. The circuit is from...