Make your own 180 Amp TIG Welder...
Here's his list of features:
1/ AC-DC welding variable via two thumbwheel switches from 1% (all Negative) right through full range of AC to 99% (all Positive).
AC frequencies available from 15 to 400 Hz
2/ Pulse Frequencies fully variable from .3 to 10 Hz This does away with having to pulse the foot peddle on thin materials.
3/ Variable control for Maximum Welding Current available to the Foot peddle control.
4/ Variable Start Current (period of higher current available (higher than max set) for short time heating of thick materials)
5/ Variable Start time for above.
6/ Variable End Current (Crater).
7/ Variable End Current time.
8/ Variable Gas Start time.
9/ Variable Gas End time (Dwell).
10/ HF Arc Start.
11/ Opto Interupter / Potentiometer foot peddle current control.
The page is packed with photos, schematics, even printable PDF's. It's a great piece of work.