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.
The integrated circuit used in this project is unusual and it includes internal transistors that...
Originally this circuit is from an English magazine, but I found it in Argentina's Radio Chassis...
Found in an Electronic Design from the 90's, this circuit supplies voltages according to the...