Abstract: A combination transformer with common yoke core characterized by the combination of a main transformer and series transformers, which transformers have separate and complete core and coil assemblies with a common core leg or yoke to reduce the core size, weight and loss.

Abstract: An electric transformer characterized by a transformer tank having an opening with a conducting closure panel in the opening and electrically insulated from the tank, a plurality of first and second conductors of opposite polarities leading from the transformer coil-core assembly with the conductors of opposite polarity comprising forward and return paths. A conducting tubular structure mounted on and extending inwardly from the inside surface of the panel and the return path conductors being connected to the corresponding tubular structures while the forward path conductors extend through the tubular structure and the panel to an external source.