The function of this circuit is to keep the terminal voltage of DC supply constant irrespective of variations in the input AC or output load. Normally zener diodes and transistors are utilized for voltage regulation.
There are two types of basic voltage regulators:
- Series voltage regulator
- Shunt voltage regulator
Series voltage regulator
In a series voltage regulator, the controlling device is connected in series with load and to regulate the output it must all times absorb some of the supply voltage.
Shunt voltage regulator
In a shunt regulator, the controlling device is parallel with the load, and to effect output regulation it must pass current at all times. These voltage regulators are used where the load is relatively constant.