Found in a 1964 Electronic Design, this circuit for 300 mA loads uses components from that period. It produces a rapid load control trigger.
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...