This high voltage oscillator with a neon lamp was found in a 1969 documentation. The circuit is synchronized by pulses of 1 kHz. The power voltage is 160 V.
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...