Esab Welding & Cutting Products ( says its MigMaster 173, MigMaster 203 and MigMaster 253 single-phase MIG welding machines offer performance comparable to that of a three-phase unit (CO2 or Ar/CO2 mixture) because of Esab's Power Smoothing Device. Each machine is equipped with a multi-step voltage switch and wire-speed potentiometer for adjusting welding parameters for a variety of applications. Spot time and adjustable burnback are built in.