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I made one from an old microwave transformer a few years ago. Works well, 4V about 100A i'd say.
Some background. FYI this is super dangerous and basically shouldn't be done by anyone. Ever.
Microwave transformers massively up the voltage (i.e. secondary:primary coil ratio is a high number) so we actually change where we apply 240VAC to what was the secondary coil.
Then we replace the primary windings with some super thick earthing wire (about 6mm2 - ish) I only did 4 windings as i wanted 4V, i.e. wanted about a 60:1 (primary:secondary) ratio
Then put a 240V switch on the primary coil side (what was originally the secondary) and used some plywood to hold it together and some copper pipe for the welding surfaces.
I was pretty scared to turn this bad boy on originally but it worked a treat.
Wouldn't advise it following my lead but i had a good time making it
Hello Mr. Lopez. I am interested in building a welder like yours. May I know what kind of transformer you used. Regards from Japan, Ray
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Posted:Jan 14, 2011
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