The circuit is from 1994 National Semiconductor documentation. The component is not easy to obtain, but there are equivalents that can be searched.
This small MW transmitter emits its signals at a distance of a few tens of meters, depending on the...
This circuit, found in a 1988 documentation consisting of an audio switch that turns off the load...
This circuit was obtained in a 1960 transistor manual from Sylvania. The circuit uses small...