Since someone asked for it, here's my project log of building a TIG welder from the ground up (not from a stick welder). Three transformers provide 20 volts each, at probably 50 amps each. I'm going to need to install a 240 volt outlet if I really want some power, the power factor on the transformers (rewound microwave oven transformers) is pretty bad. So far I've tried the transformers and the HF/HV starter, but not together (need a cap for a low pass filter to prevent HV entering the transformers. Power control is provided by a phase angle control, two anti-parallel SCR's (while essentially a triac, triacs have problems with inductive loads, sometimes they dont turn off at zero crossing). Pictured is a triac, although im going to the surplus store tomorrow for the biggest scr's they have. Tig torch is WP17V, with valve.
Some pictures
MT1 broke off the triac |