MIG welding with DC power supplies

I have a few power supplies PP-1104C that are rated 100 A at 14 VDC and 50 A at 24 VDC. Not quite sure yet, but I think that they are CC
power supplies. I would like to know if I could rig up one or even two in parallel or in series (100A at 28V) with a mig gun like Ready Welder and weld with that.
Some pictures of them are at
http://web.govliquidation.com/auction/view?auctionIdv7646
I figure that 200A at 14 VDC can weld just about anything.
Any thoughts?
i
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Ignoramus2596 wrote:

YOu will need a higher voltage than 14 volts. 25 volts or more.
John
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OK... If I put two of them in series, I could get 100 amps at 28 volts. Would that be good enough for welding most stuff. I hope that I am making sense, I am a little drunk at the moment (wife bday)
i
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You probably need some inductance in series as well, to stabilise the arc. My old MIG had a straight, open core, with (afair) a single layer of seriously thick wire on it.
Ignoramus2596 wrote:

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Ignoramus2596 wrote:

If you put the two in series you will have the combined voltages but the current capacity of the smaller one.
--
Fred R
"It doesn't really take all kinds; there just *are* all kinds".
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Sure. They can do 100 amps at 14v. So, two of them could produce 100 amps at 28 volts, if put in series. That, I suspect, is not so bad for MIG welding.
Their current meters show a red area above 100 amps, so, I think, they could possibly go higher at reduced duty cycle.
i
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Just a word of warning - remember the supplies might not work stacked. Most will. But make sure there is not a problem early on.
I don't see much voltage isolation issue - being so low, but there might be internal circuits that don't like it.
Martin
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder
Ignoramus20905 wrote:

-
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On Sun, 26 Feb 2006 21:02:00 -0600, Martin H. Eastburn

Good point. See my reply to Don, with a pointer to the schematic. It does not seem that any output is connected to ground.

It's made to work with both 14V and 24 volts, so, I think, 28 volts will not hurt it.
i
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wrote:

Now is a great time to go experiment!
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"Ignoramus2596" wrote: (clip)I think that they are CC

^^^^^^^^^^^^^^^^ Isn't that what you would use for stick? I think you want constant voltage for MIG.
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wrote:

Leo, I am sorry, I was and still am a little drunk, I meant to say CV.
i
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Ignoramus2596 wrote:

The grounding arrangements on these might screw you over. unless the units wind up truly floating related to each other they couldnt be rigged up in series without causing then instant smoke and crack of the ic's rupturing on the 100A dead short
I think it will have issues trying to gang both PSU's together without using a LOT of protection to keep the business end of the PSU apart.
Because they are voltage and current sources they wont be as simple as hooking up 2 batteries (Voltage source only) and likely one mistake and you will be faced with 2 power supplies making smoke.
but have fun with it I'd have to look to find 3 computer PSU's for that little so its not like youre really out on the parts cost.
Nothin to lose but your eyebrows
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Yes, the cost is negligible, but getting rid of smoke smelling hunks of metal is not as much fun.
Replying to another poster, I will see when I get them, but their output relinking arrangement makes me hope that DC output is isolated. (as is usually the case) With that, putting them in series should be possible.
i
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