Found in an American documentation from 1969, this astounding circuitry makes a relay operate on 3 Hz cycles. The relay is of the high voltage type of the time.
This small transistor amplifier was found in an ancient American documentation. Transistors can be replaced...
This simple oscillator generates a 455 kHz signal. The circuit is from an 80's documentation and its...
We found this circuit in an English publication in 1979. The diode should preferably be germanium and...