Automatic Voltage Regulator

An AVR takes in a range of voltage levels and automatically outputs a voltage with a much narrower range of voltage levels. For example, a typical automatic voltage regulator for power quality application may have an input voltage range of +10% to -25% of the nominal input voltage and convert this to a regulated voltage range of +3% to -3% of the nominal output voltage as shown the graphic for a 480V input and output. A voltage regulator may have a symmetrical input voltage range (e.g. +10% to -10% of nominal voltage) or an asymmetrical input voltage range as shown in the example. The choice of symmetrical versus asymmetrical input voltage range is dictated by purpose and design of the voltage regulator. The output voltage regulation range is almost universally symmetrical (e.g. +3% to -3% of nominal output voltage).