Voltage regulator, any electrical or electronic device that maintains the voltage of a power source within acceptable limits. The voltage regulator is needed to keep voltages within the prescribed range that can be tolerated by the electrical equipment using that voltage.

What happens when you have a bad voltage regulator?

A damaged or failed voltage regulator can rapidly diminish the alternators ability to cycle power from the battery. This may cause the vehicle to experience dimming or pulsating external systems, such as headlights and dashboard elements.

What is inside voltage regulator?

A voltage regulator generates a fixed output voltage of a preset magnitude that remains constant regardless of changes to its input voltage or load conditions. A linear regulator employs an active (BJT or MOSFET) pass device (series or shunt) controlled by a high gain differential amplifier.