This circuit was obtained in a 1968 manual of General Electric. The components used are of the time, but they admit equivalent. Observe the optical feedback system for control.
In this circuit of an American documentation of the 90s, when the light is cut, we have the...
The circuit shown was found in a 1995 documentation. This circuit is powered by a voltage of 6 to...
This simple regulated power supply was found in a 1977 documentation. The zener diode determines the...