This circuit was obtained in an Electronic Engineering of the 90s. The operational amplifiers and the sensor are from that time. The circuit has symmetrical power supply.
This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light...
Although indicated in the original publication of the 1980s as a capacitance switch, the circuit...
In the figure below we have a simple way to do chroming, silvering or another type of...