This circuit for old flashes with xenon lamps was found in a Radio Electronics magazine from June 1966. The sensor is a photoelectric cell from the time. Power is supplied by a 9 V battery.
Found in a 90s Radio Electronics, this circuit can be used in high voltage experiments, ionizers,...
This VFO circuit generates signals from 2 Hz to 50 Hz. We found it in Popular Electronics from...
This circuit, published in the 1980s, can be applied to operational amplifiers of almost any type....