Found in a Raytheon transistor manual from the 1950s, this circuit uses one of the first commercially available transistors, the CK722. The circuit is for using a small speaker as a microphone.
With the circuit shown, you can have a fast response with a Darlington configuration. The circuit is...
We found this multiple thermostat circuit in July 1980 Radio Electronics magazine. It uses...
Mouser Electronics is already providing new MOSFETs EF SIHx28N60EF of Vishay series for voltages...