Voltage regulator:
A voltage regulator is an electrical regulator intended to automatically keep a constant voltage level. A voltage regulator is an instance of a negative feedback control loop. It might utilize an electromechanical mechanism, or electronic components. Depending upon the design, it may be employed to regulate one or more AC (alternating current) or DC (direct current) voltages.
Electronic voltage regulators are found in devices like computer power supplies in which they stabilize the DC voltages employed by the processor and other elements. Within auto mobile alternators and central power station generator plants, voltage regulators control output (o/p) of the plant. Within an electric power distribution system, voltage regulators might be installed at a substation or along distribution lines that's why all customers receive steady voltage independent of how much power is drawn from the line.