This circuit was found in Radio Electronics magazine from August 1966. The transistors are from the time and the power supply from the power grid is included.
Obtained in an American documentation from 1976, this circuit has a constant current source for...
The output of this voltage regulator depends on the zener diode. The current depends on the...
This well-known circuit triggers a relay when light striking the phototransistor is cut off. The...