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.
This circuit uses unijunction transistors and drives a small speaker through an output...
This circuit, found in a publication from the 1980s, can have its output voltage determined by the...
The operational amplifier for this circuit, found in a 1979 publication, may be the 741....