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.
This circuit was found in a 1977 radio amateur manual. Integrated circuits are operational...
In the figure we show a configuration for a crystal-controlled overtone oscillator using a...
The transistor used is a high current Darlington, but an equivalent discrete configuration can be...