Ac power stage bypass in a welding power source

A DC-AC selector stage for a welding power source, comprising:

• a first switch element comprising a first relay and a first switch arranged in parallel between an output of a secondary rectifier downstream of a transformer and a first output power terminal of the welding power source;
• a second switch element comprising a second relay and a second switch arranged in parallel between a center tap of the transformer and a second output power terminal of the welding power source;
• a third switch element comprising a third switch between the output of the secondary rectifier and the second output power terminal;
• and
• a fourth switch element comprising a fourth switch between the center tap of the transformer and the first output power terminal, wherein:
• the DC-AC selector stage is operable in an AC power mode in which the first and second relays are in an open state and the first, second, third, and fourth switches are operated as an H-bridge inverter to convert DC power to AC weld power;
• and
• the DC-AC selector stage is operable in a DC power mode in which the first and second relays are in a closed state and the third and fourth switches are in an off state to pass DC weld power to the first and second weld output terminals of the welding power source.