Also known as an Automatic Voltage Regulator (AVR) or Voltage Regulator (VR), an Automatic Voltage Stabiliser (AVS) stabilises the mains power supply voltage to a load.
It is a feature of Line Interactive uninterruptible power supplies and provides protection from power problems such as sags, brownouts and surges.
Automatic Voltage Stabilisers have a wide input voltage window (+20/-40%). If the input supply voltage is too low, the AVS uses a transformer to boost (step-up) the output voltage. On the other hand, if the input supply voltage is too high, the AVS reduces the voltage to a safe operating range (this process is known as buck or step-down).
Output voltage tends to track the input voltage window as there’s no need for any voltage regulation.
Some AVS incorporate a filter that provide both the load and the stabiliser itself with limited protection from spikes, transients and electrical noise.