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.
This thermostat was found in a 1997 publication. It can be powered by 6 V with the use of a...
This switched-mode circuit was found in the April 1976 issue of Radio Electronics magazine. The...
This circuit was obtained from an old American publication. Transistors are germanium types of the...