System and method for converting an AGTAW welder into an AGMAW welder

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG.
1 illustrates a prior art AGTAW welder 1 which may be converted into a AGMAW welder by the system and method of the invention.
Such welders 1 typically include a water cooler assembly 3 for preventing the weldhead of the welder 1 from overheating by circulating water through it, a power supply 5 for supplying electrical current to a TIG weldhead 7, and a constant current control circuit assembly 9 for controlling the electrical characteristics of the power generated by the power supply 5.
The TIG weldhead 7 includes a tungsten electrode 13 surrounded by a gas shield 15 (shown in phantom).
A source of inert, pressurized gas (not shown) is fluidly connected to the gas shield 15 for constantly displacing ambient atmospheric oxygen away from the molten puddles created at the distal tip of the tungsten electrode 13 in order to minimize oxidation and corrosion in the resulting weld.
The weldhead 7 further includes an electrode extender and retractor motor 19 for maintaining the distal tip of the tungsten electrode at constant distance away from the workpiece so that the voltage used to drive the welding current remains substantially constant.
Disposed opposite from the electrode extender and retractor motor 19 is the wire feeder assembly 21, whose purpose is to feed weld wire between the distal end of the tungsten electrode 13 and the molten puddle being created on the workpiece during a welding operation.
To this end, the wire feeder assembly 21 includes a wire feeder motor 23 for feeding weld wire 25 from a spool 27 through a wire guide 29.
As is schematically illustrated in FIG.
1, the wire guide 29 feeds the weld wire 25 at a proper orientation between the distal end of the tungsten electrode 13, and a workpiece 31.
The power supply 5 of a prior art AGTAW welder generally comprises a transformer assembly 34 connected to a power source 36.
The transformer assembly 34 converts alternating current from the power source 36 into direct current, and feeds this direct current into a switching circuit assembly 38