A welding system with an electronic control includes four switching elements coupled together to form a bridge. An inductor with a center tap is located between two legs of the bridge. A load, including an output electrode and the metal parts being welded, is coupled between the center tap of the inductor and the other two branches of the bridge. Two of the switching elements are turned on and off at a relatively high rate to control the power to the load. The other two are turned on and off at a relatively low rate to control the duty cycle and polarity of the load voltage and current.