I happened to check the original page link (http://www3.telus.net/public/a5a26316/TIG_Welder.html) and it seems to be working again, and updated more recently. I'd therefore suggest going to the current page instead of looking at my copy here.
This page was originally from a website at the address http://www3.telus.net/public/a5a26316/TIG_Welder.html. I found a link to it in a forum post on building TIG welders. However, as of 25/04/11, this URL is no longer valid. Fortunately, with the magic of the Internet Archive Wayback Machine (web.archive.org), I was able to piece together the page and the associated files. They are reproduced here exactly as they appeared on the original website. The only change I have made is to make the images link to bigger versions. The date of the Wayback backup is 9th March 2009.
I make no claims as to the veracity of the material here, it is provided solely for information. All content is by the original author, Dave Barrett, whose email is dave.barrett@creo.com; however, I don't know if this email address still works.