This circuit of 1965 documentation makes use of a tunnel diode to retard a pulse without distortion. The components are from the era.
This circuit was found in a 1974 documentation. The bipolar transistor can be the BC548 and at the...
Among other things, this oscillator is suitable for practicing Morse code. The circuit is from a...
An interesting type of sensor for specific applications is the sensor formed by piezoelectric...