Stick Welder to TIG Modification.

This circuit should be installed inside the welder or in a separate box between the welder input power cable and your line voltage. It is rated for 50 amps, if a larger circuit is needed change the SCR's to a higher amperage. To print the schematic place your mouse cursor over the image and right click your mouse, then select print target. You will need to make a foot pedal to house variable resistor R4. You will also need to use your skills to have the foot pedal rotate the variable resistor.

The following electronic parts can be obtained from Mouser..
  • R1, R2 - 100K, .5W Resistor, Part # 30BJ500-100K.
  • R3 - 1K, .5W Resistor, Part # 660-RC1/2T102J.
  • R4 - 250K, 2W Resistor, Part # 526-501-0017.
  • C1, C2 - .1uf Capacitor, 630VDC, Part # 146-630V.1K.
  • D1, D2 - 1N4007 Diode, Part # 512-1N4007.
  • D - Diac, 30 - 40 Volts SMT DO-214AA, Part # 511-DB3.
  • F1, F2 - Fuse, .5A with holders, Part # 576-03420004HPXL.
  • SCR1, SCR2 - PMOD, DUAL-SCR, 1200V, 60A, Part # CD431260A-PRX This part is from Galco..