Found in a 90s Radio Electrconics, this circuit is an operational one with a power stage using two transistors. The output current can reach several amps.
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...