We found this passive circuit in the February 1995 Electronics Now magazine. The circuit is passive, presenting only attenuation that must be compensated by an amplification stage.
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....