converting ac to dc

[Soundguy]

Been kicking around a test idea recently. I have some high capacity ( read 100-120a ) rectifiers with associated aluminum heatsinks.. would be easy to work up a full wave bridge... while my big welder is a hobart235acxl.. and out of the question.. I also have a lil CH 30/7a a welder I use on sheetmetal... 1/16 and 5/64.

seems doable unless I'm missing something.

anyone ever do something like this? ie.. external rectifier pack for an ac welder?


soudnguy

 

[k0ua]

Been kicking around a test idea recently. I have some high capacity ( read 100-120a ) rectifiers with associated aluminum heatsinks.. would be easy to work up a full wave bridge... while my big welder is a hobart235acxl.. and out of the question.. I also have a lil CH 30/7a a welder I use on sheetmetal... 1/16 and 5/64.

seems doable unless I'm missing something.

anyone ever do something like this? ie.. external rectifier pack for an ac welder?


soudnguy

Yep, have seen it (or at least I seen a little on TV!) Starts at about minute 3 a shot of the rectifier bank


[ame=http://www.youtube.com/watch?v=9lV4tzg4zn0]Homemade Tig Welder - Tig Welding Old School with Scratch Start - YouTube[/ame]

James K0UA

 

[k0ua]

Oh by the way.. he says at the end.. "if you want to get your feet wet"..

Well what ever the He** you do, DO NOT "get your feet wet" as that can be dangerous while welding:laughing::laughing:

James K0UA

 

[deereman75]

A friend of mine who lives down the road (happens to be the mayor of the city), has a store bought version. Uses it with an ac miller thunderbolt, said it works great.

 

[rcowan]

Did you try it and was there smoke?

RC

Been kicking around a test idea recently. I have some high capacity ( read 100-120a ) rectifiers with associated aluminum heatsinks.. would be easy to work up a full wave bridge... while my big welder is a hobart235acxl.. and out of the question.. I also have a lil CH 30/7a a welder I use on sheetmetal... 1/16 and 5/64.

seems doable unless I'm missing something.

anyone ever do something like this? ie.. external rectifier pack for an ac welder?


soudnguy

 

[Soundguy]

it's on my list to do.. just have to get time.

i'm sure there will be smoke.. from burning rods.

the rectifiers are in some cases, depending on which i use, up to double rated for my application..

 

[monckywrench]

Plenty of folks have done it. I've seen some pics on Shop Floor Talk and Weldingweb but don't have the links handy.

Go for it!

 

[ThomasH]

That's all that was in an old Century 300 amp stick welder that I used to own. A big split transformer with an arm that moved the two halves towards each other, and a large selenium rectifier. The selenium rectifiers come in a heat sinked stack, so it's essentially the same thing. Just make sure the voltage rating on your rectifiers is high enough, open voltage X 1.5 minimum.

Good luck!

 

[Soundguy]

i remember the old sel rectifiers.. noisy suckers...

 

[k0ua]

i remember the old sel rectifiers.. noisy suckers...

Yes and the biggest rotten egg smell you have ever smelled if you let the smoke out of one of them.

James K0UA

 

[undercut]

So what's the desired effect from rectifying? Smoother arc?