This circuit activates an old cassette recorder when the phone is being used, thus making it possible to record the conversation. The circuit is from a Hands On Electronics from the 90s.
Found in 1967 General Electric documentation, this circuit is intended for the control of...
We found this circuit in an English publication from 1980. It memorizes the peak of the input...
This 200-mW amplifier uses one of the first commercial power transistors. The circuit is from a...