This circuit that we found in a 1990 documentation uses an LED as a sensor. The operational amplifier is equivalent to the 741 and the trigger adjustment is made in the potentiometer.
This simple electronic toy organ produces an interesting sound, which can be used by the most...
This SCR circuit was found in an American 1980s documentation. The circuit is still current,...
The sensor of this circuit can be any phototransistor and the SCR can be the TIC106. The circuit and...