Found in a 90s Radio Electronics, this circuit can supply currents of a few amps, according to the power transistor. The power transistor must be equipped with a heat sink.
This simple electroscope with bipolar transistors is not the most sensitive, but can detect static...
This oscillator for various frequencies was obtained from a 1980s telecom documentation. The...
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...