This circuit was found in the July 1978 issue of Radio Electronics magazine. The circuit uses a common digital voltmeter as the indicator. The sensors are integrated circuits of the time.
Suggested by General Electric in 1965 documentation, this circuit controls the current at a load...
Found in Popular Electronics from the 1980s, this circuit uses two operational amplifiers from...
We found this circuit in a Hands-on Electronics from 1985. The circuit is based on common...