This DC motor control uses a power operational amplifier. We found it in December 1984 in the Radio Electronics magazine. The amplifier must be mounted on a heat sink and the maximum current is 1 A.
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...