To gain the buck/Increase element, all of that is required is 2 separate switches so which the AC enter can be connected to one of several two primary taps, when the load is linked to the opposite, So utilizing the key transformer's primary windings as an autotransformer. From Java 11 https://zion79f45.blogscribble.com/33865285/the-smart-trick-of-uninterruptible-power-supply-ups-that-no-one-is-discussing