Arc welding machine and plasma cutting machine

摘要

In an arc welding machine and a plasma cutting machine, by connecting the output of a second DC power supply unit to a circuit fed by a first power supply unit, a DC high voltage from the second DC power supply unit is applied, during start, across an electrode and a base metal which are not in contact with each other, so that radiation noise can be reduced considerably and leakage of high frequency power from an extension cable can be eliminated to attain steady arc start.