Anybody Know What This Is?

[cointoss]

I bought a used Lincoln AC welder recently and the the first owner built a plywood box to fit on top with a light bulb and this electrical element. I figured he made the box to keep his rod dry. Anyway here it is anybody know what it is?

 

[jones6780]

The hex with the purple band are diodes. See the + and - marks on the far side? Why, I don't know.

Russell

 

[namyessam]

The hex with the purple band are diodes. See the + and - marks on the far side? Why, I don't know.

Russell

Would it turn the lincoln AC welder into a DC welder? Diodes only let electricity flow one way don't they??

 

[dex3361]

Thats a bridge rectifier used to make a DC welder out of an AC welder. Home made and quite workable.

 

[M E Race]

Would that work on a Lincoln 225 cracker box ? It seems that would be far cheaper than buying another AC/DC machine.

 

[Mark @ Everlast]

What??? are you serious? DC duty cycle isn't half. It shouldn't be any different. They way the tombstones are configured, they do have half the amp output...but that shouldn't be ANY reason it is inferior or not to buy it. Typical misleading information to sell what they have in stock.

 

[deereman75]

Saw it right away, converts it to dc. A farmer friend of mine (now the mayor) has a factory made version of that, on an old Canadian miller thunderbolt. He said it worked real nice. Nice little find, that would make the old tombstone much nicer.

 

[jwmorris]

If you had much welding to do at any one time you would want the diodes in a heat sink but it works.

 

[Dave M7040]

Take apart an old large battery charger and you will find the same diode parts. In the charger, just like in a welder,there is a transformer to lower the voltage to a level suitable for charging a 12 volt or 6 volt battery and then diodes to change Ac to DC.

Dave M7040

 

[CNC Dan]

As others said it is a bridge rectifier.
You may find it helpful to add an inductor (coil) after the diodes to further stabilize the current.

I think the guy from weldingtipsandtricks.com shows one in one of his videos.

 

[BukitCase]

Check this out

Fileiode bridge alt 1.svg - Wikipedia, the free encyclopedia

in your pic, the two bolts in the CENTER of the brown board connect to the OUTPUT of your AC welder - the "-" and "+" go to work and stinger. 99.9% of the time, stinger will be "+" .

As said, a heat sink and/or fan would be a good idea... Steve

 

[stuckmotor]

What??? are you serious? DC duty cycle isn't half. It shouldn't be any different. They way the tombstones are configured, they do have half the amp output...but that shouldn't be ANY reason it is inferior or not to buy it. Typical misleading information to sell what they have in stock.

Mark,
Thanks for correcting me. I could have confused what the salesman said about the amp output with the duity cycle. It's been a long time. The salesman was a nice guy.

 

[cointoss]

Thanks for the response guys, I just didn't have a clue. Probably won't hook it back up, what little welding I have to do the Linoln AC can stay AC.

 

[PILOON]

Cointoss,
I sent you a PM.

 

[CNC Dan]

This is a video of someone using a rectifier to tig weld:
http://www.youtube.com/watch?v=CA3w9Wq5mh0&feature=youtube_gdata_player