# Constant Voltage Vs Constant Current



## Uglydog (Jun 7, 2016)

Not sure if this should be in a welding section. However, because at the core it's an electrical questions and not a welding question I posting it here.

I did a small job for guy for which I wasn't going to charge $.
He insisted that I take his vintage SAE200J Lincoln welder as a token of he appreciation.
I figured that the copper would be worth something if I couldn't get her operable.
While she was in an out of service calf barn, she'd obviously been outside at some point, as I needed to dig out the grass and vines from the inside.
After chasing out the mouse nest from the 2pole push button switch box and rewiring her from 3phase, 440v to 220v. And adding a little motor lube. She is operable. Note: the 3ph motor connects 123 instead of 456. The wiring diagram was nearly indecipherable. Yep, blew a few fuses getting there.

Anyway she welds nice! I especially like the constant voltage feature which allows me to set the "dig" or penetration into a key hole. She has a 30% duty cycle and will cut hours on my TIG unit.

Here is the long awaited electrical question....

I know that CV is a MIG mode, and CC is a Shielded/TIG mode.
I found this video to be helpful in my understanding of voltage vs current.

However, can anyone explain why  MIG is CV and TIG/Shielded is CC?
Electrically, what is the difference between MIG and TIG/Shielded?

Regardless, I like the fact that the CV adj on this vintage SAE220J allows me to adjust penetration.

Thank you,



Daryl
MN


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## rpmMan (Jun 7, 2016)

Daryl

i am not a welder... but this link sums it up pretty well

rich

http://www.lincolnelectric.com/en-g...stant-current-vs-constant-coltage-output.aspx


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## chips&more (Jun 7, 2016)

That’s a nice DC welder you have! I remember using one of them back in my high school days. I could actually weld something together using that welder.


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## CluelessNewB (Jun 7, 2016)

Not a welder either but that is a wicked kewl looking machine!


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## Uglydog (Jun 7, 2016)

rpmMan, 
Thanks for the link!!

Daryl


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## barnett (Jun 7, 2016)

Nice welder !! Just wondered is it 3-phase? 
My friend has one and it welds very nice, its 3-phase and he runs it on a rpc. 

Tom


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## David VanNorman (Jun 7, 2016)

The last one I was 3 phase , I would think they  were made in single phase also.


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