Welding apparatus having a three-phase transformer

摘要

The invention relates to a welding apparatus having a three-phase transformer, whose primary windings are connected in star in three-phase operation and whose secondary windings, which are in star, supply the welding voltage via a rectifier circuit. With the aid of a mode switch, winding sections (selected in a particular manner) of the primary windings are reversed and interconnected for single-phase AC operation such that there is only a small power loss in comparison with three-phase operation.