This detector uses an unusual sensor today. The circuit is from an 80s documentation. Its sensitivity is 10 ppm. The transformer has two secondary voltages.
August 2016 - It can be purchased from Mouser Electronics new chips from Dialog Semiconductor, the...
With this circuit it is possible to fire an SCR from the light that falls on a phototransistor. The circuit...
Interval pulses emitted by this circuit are picked up in a medium wave radio nearby. The circuit is...