Systems and methods providing controlled AC arc welding processes

摘要

Systems and methods for providing controlled AC TIG arc welding processes is provided. In AC TIG arc welding power source embodiments, configurations of main and auxiliary bridge circuits allow for the directional switching of the output welding current through the welding output circuit path and selectively provide one or more high impedance paths to rapidly decay the arc current. The high impedance path aids in the low spatter transfer of molten metal balls from consumable to a workpiece, via an arc generated by a tungsten electrode, and further aids in the maintaining or the re-establishing of an arc between the tungsten electrode and the workpiece during welding.

主权项

1. A TIG welding power source comprising:
a power conversion circuit configured to convert an input current to an output current; a main bridge circuit operatively connected to the power conversion circuit and configured to switch a direction of the output current through a welding output circuit path operatively connected to a welding output of the welding power source at the command of a controller of the welding power source; and an auxiliary bridge circuit operatively connected to the main bridge circuit and configured to introduce a high impedance path between the power conversion circuit and the welding output circuit path at the command of the controller of the welding power source, wherein a welding output current of the welding power supply is an AC output current having a plurality of positive portions and negative portions and wherein said welding output current has a frequency of at least 1 KHz, and an average current output of at least 100 amps.