01-06-2016, 09:43 PM
I used to have an old Lincoln Dialarc AC stick welder. Huge machine with steel wheels that seemed like it weighed a ton when you had to move it. Beautiful arc that was butter smooth but it had a major problem. Couldn't weld with it for 5 minutes because it would turn the amperage down on it's own while you were welding. Crank the dial up to 125 amps and start running a bead, and before long it's dropped itself down to 70 amps! 
I asked one of the (old-timer) technicians at the local welding shop about it when I went there to buy some new cables for it. He knew right away that I wasn't totally crazy and imagining it turning itself down. "Take the hood off, and drive a piece of wood between the bottom of the case and the bottom of the transformer." At that point I thought HE was crazy!
Danged if it didn't fix it though. Never had a problem with it after that.
It took up a lot of space in my tiny shop though so I decided to get rid of it. Gave it to my younger brother's boss to use at home, and earned him a few brownie points.
Thinking back on it now though - and that huge copper wound transformer...
Of course a year later I had three new welders taking up even more space than before...
I asked one of the (old-timer) technicians at the local welding shop about it when I went there to buy some new cables for it. He knew right away that I wasn't totally crazy and imagining it turning itself down. "Take the hood off, and drive a piece of wood between the bottom of the case and the bottom of the transformer." At that point I thought HE was crazy!
Danged if it didn't fix it though. Never had a problem with it after that.
It took up a lot of space in my tiny shop though so I decided to get rid of it. Gave it to my younger brother's boss to use at home, and earned him a few brownie points.
Thinking back on it now though - and that huge copper wound transformer...
Of course a year later I had three new welders taking up even more space than before...
Willie