To get the buck/boost feature, all that is needed is two individual switches so that the AC enter can be linked to among the two Main faucets, although the load is connected to the opposite, thus utilizing the main transformer's Main windings as an autotransformer. Illustration #seven - you forgot https://cocoagriculture83704.full-design.com/the-smart-trick-of-uninterruptible-power-supply-ups-that-no-one-is-discussing-76192296