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.
In the circuit that uses a PIC16F84, the audio present at the input will have its level controlled by...
This circuit was obtained in a June 1987 magazine Hands-On. It is a circuit that indicates on two...
This circuit is from a cookbook to timers. The circuit is triggered by an external signal and,...