An Automatic Voltage Stabilizer (AVS) or automatic voltage regulator (AVR) is a single phase and three phase high accuracy full-automatic power supply product. It is consits of servo motor, automatic control circuit and various other components.

When the power network voltage fluctuates or the load varies, the automatic control circuit will send a signal to drive the servo motor. This can then adjust the position of the carton brush inside the automatic voltage stabilizer. The output voltage is then adjusted to the rated value and a steady state is maintained. Automatic Voltage Regulators and Stabilizers have many domestic and industry applications such as large type electromechanical equipment, metal processing equipment, production line, construction device, elevator, medical equipment, equipment of light and textile industry, air-condition and lighting used for industry, agriculture, traffic, military, railroad, scientific culture, etc. Even TV sets and other household appliance.