i have some questions about tig welder control circuits, hope some one can help.

in a tig welder you set a maximum amperage for the output then use the foot pedal to control the amperage within that range. how does the circuit work or what is the name for that type of circuit?

can anyone please point me to a circuit or explain how to build a circuit to do this?

thank you, cary

Try googling for "TIG welder +electronic current control"

Go to the Miller welding site and check the service manual for one of its TIG welders. You may need to register. Miller provides the schematics for most of its welders. John

Originally Posted by BrownOut

We have a resident welder expert on here. He'll be along to answer the quetion soon, I'm sure.

Who is that then? Cause I got a heap of questions.

Mike.

thanks for the replies!

MR. RB- i googled and search this site, using every way of phrasing i could think of. thats why i asked for a circuit "name or type"

jpanhalt- i tried miller site but they want a serial# along with a model#. tried Lincoln, their schematic was just a wiring diagram.

brownout- i was hopping tcmtech would answer


cary

Originally Posted by jpanhalt

I have a Miller Dialarc HF, circa 1983, number 901-782 ( I think). If you are interested in something with that old technology, I will drop by the shop and get you a serial number.

John

Edit: The circuit diagram will be just that. It will not describe how it works. You will have to figure that out from the diagram.

John, if it's not too much trouble that would be great! i'm new to electronics but i'll give it a shot.

cary

It is actually a Dialarc HF-P, s/n JD709609. Sorry, my mind is getting weak, I forgot the -P in the model number. I bought it new in 1983 or 1984.

It is a great welder and has not given me a single moment of concern. The foot control may not be linked to that s/n, but there really is not much to the foot control. Never had it apart, but assumed it was just rheostat or something similar. There are not a lot of electronics with this machine.

John

john, thank you for the serial number! i'll check out the miller site and let you know how i make out.

thanks again, cary

ok, the amp control seems to be a set of AC coils with a DC coil with varying voltage from the foot pedal, all on a transformer core. here is the pdf of the manual:
http://www.millerwelds.com/om/o315j_mil.pdf page 4 is the schematic.
in the parts list they call this a "magnetic amplifier"

don't know quite how it works. DC clamping part of the AC current is my guess?

anyhow it won't work for what i want to do.

thank you all for the replies, cary