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 oscillator shown generates a signal in the 4.5 MHz band and can be used for audio modulation of TV...
With this circuit it is possible to adapt the input of a common analog multimeter, making it...
This metronome circuit was found in an American 1980s documentation. The circuit uses the 4001...