Found in an Elektor from the 90s, this circuit can be powered directly by the power grid. The circuit uses a rectifying bridge that can be replaced by 4 common diodes.
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...