Based on the BA1404 integrated circuit, this circuit was found in the July 1992 issue of Radio Electronics magazine. The circuit is short range, but a power amplifier stage can be used.
Using an operational amplifier with FET, this circuit was found in an English documentation from...
With the first project we present, a relay is activated in the presence of light. We can use it as...
This AC amplifier has a gain of 40 dB. It was found in the May 1988 issue of Radio Electronics magazine....