Circuit and text from Mick Devine

This circuit above is a SIMPLE POSITIVE VOLTAGE REGULATOR SHUNT

Using a 13 volt zener diode, D2, this circuits provides a regulated 12 volts at 0.5 amp to a load.

The circuit above consists of a main's transformer, a full wave bridge rectifier, a smoothing capacitor and a zener diode shunt followed by a transistor emitter stabilizer.