Transformers specially designed to generate two different current and tension waves (both of the same frequency) to enable the operation of either 6 or 12 pulses drives or rectifiers. Rectifier transformers are designed taking into consideration the effects of on load high harmonic charges and the overloads caused by them. In addition electrostatic shields are provided to minimize the on load harmonic effects over the primary circuit.

These types of transformers are usually used in electrolytic processes, electroplating, and other industrial processes where direct current is applied.