Using an LDR as a sensor, this circuit is from the Radio Electronics magazine of December 1984. The operational amplifier is the 741 and the source must be symmetrical.
We found this simple operating tester 741 in a European publication in 1991. The circuit...
In this receiver the is formed by 80 turns of wire 28 or close in a ferrite rod. The handset is...
The use of a diac improves the performance of the two dimmers in the previous circuits. The...