This photoelectric sensor that triggers a relay was found in an English book from 1989. The transistor is a general-purpose type, and the integrated circuit consists of an operational amplifier.
Using an era germanium transistor, this 1960s circuit reverses the phase of relatively low...
This circuit uses amplifiers from the 60's American company Microlin. The circuit can be designed...
The idea of this circuit found in a Radio Electronics from January 1966. The idea of the...