Found in the American 73 magazine for radio amateurs, this circuit can test common quartz crystals. The circuit includes the power supply.
This dimmer for incandescent lamps was obtained from an American 1990s documentation. The circuit...
This circuit can be used in physics experiments, in ionization and in several other applications. The...
This experimental AM radio circuit was found in a 1979 English magazine. It can be fitted with a...