. voltage regulati**:
In a power supply, the Automatic holding of the output voltage to a c**stant value, despite variati**s in the input voltage or load resistance.



2. Current regulati**:
In a power supply, the automatic holding of the output current to a c**stant value, despite variati**s in the input voltage or load resistance.

3. Automatic voltage regulator (AVR) :
An automatic feedback c**trol system that is resp**sible for maintaining a scheduled voltage either at the terminals of a synchr**ous generator or at the high-side bus of the generator stepup transformer. The c**trol is brought about by changing the level of excitati**.