Salvaged from a mill (with permission) this autotransformer was providing power for the mill's main rotating machinery drive; an ancient large a/c motor some six feet in diameter probably dating from 1915 or so. The transformer's housing is cast iron with heavy sheet sides. I have not opened it up to examine the coils yet, but will take pictures when I do. It was operational when the mill ceased operation just five years ago, so one would assume it is still functional. I would like to learn more about it, so if you know more I would love to hear about it. Thanks for looking.