methods and systems for creating and controlling an ac output for welding , plasma cutting or heating are provided . one embodiment of the present disclosure achieves a desired square wave ac output and reduces the number of circuit components needed by combining components of a buck converter and a full bridge inverter . current flow paths through a power control circuit that are generated via switching of transistors in the circuit on and off are provided . in one embodiment , a pulse width modulation leg , which controls the level of current flow through an inductor , is provided . certain embodiments include a bidirectional buck converter that converts an unregulated dc flow to a regulated dc flow through an inductor . in one embodiment , a steering leg is provided , which controls a direction of current flow through the inductor . additionally , an output clamp circuit , which suppresses the parasitic load inductance during polarity reversal is provided .