In the event your voltage amounts are unstable (ie: power stays on, but the particular voltage degree differs a good deal from the 220V typical), then I think that's the sort of situation exactly where an AVR is useful. all classes and interfaces in the superclass hierarchy (e.g. see Java https://damienihdew.blogripley.com/34473972/uninterruptible-power-supply-calculator-can-be-fun-for-anyone