This circuit was found in a 80's Popular Electronics. The sensor can be any phototransistor. The circuit is indicated for an audio link modulated in pulses.
We found this circuit in a 1998 documentation. It tests common household appliances to see if they...
We found this electronic organ circuit in a 1987 documentation. The circuit should be powered by...
This circuit was found in an Electronic Design from the 80's. It shows how to use a MOSFET driver with...