Abstract: A high voltage transformer winding assembly is disclosed which enables tuning to preferably provide a rectangular pulse output for improving voltage regulation. The winding assembly comprises a pair of winding subassemblies mounted on opposite legs of a magnetic core. Each winding subassembly is provided with a plurality of windings. The plurality of windings of the two subassemblies are interconnected to form a plurality of winding pairs. The interconnection is such as to form an a-c null or minimal a-c voltage substantially at the connection point between the windings making up a winding pair. When the start turns of the windings are interconnected to form the winding pairs the a-c null of each winding pair appears adjacent the core to reduce the likelihood of corona discharge. The plurality of winding pairs are connected in d-c series aiding by means of diodes which provide a-c isolation between the winding pairs.