Found in an American publication from 1968, this circuit aims to keep the torque of a DC motor constant. The power transistor depends on the motor.
Found in Popular Electronics from the 90s, this circuit uses still common components. Its power is 20...
This 1969 Philips documentation circuit makes it possible to control an engine through the sound...
Using a CA3059 this circuit was found in the July 1995 Electronics Now magazine. The triac must be...