Re: Please help

Hi Mariano,
The more I read on the TIG process, the more I convince myself that
trying to convert a DC mig or tig to AC (aluminum) mode will be
uneconomical. It ends up that the pulsing of the DC weld current is
not enought to produce the cleaning action. The weld arc must
alternate both negative (for heat/penetration) and
positive (for oxide blasting/cleaning of the puddle). At these
currents, big IGBTs or SCR's would be needed, and the cost of
this plus the high frequency arc start/stabilization would put
you in the range of the Lincoln unit mentioned. Is your Tig an
invertor type, of transformer type. If its transformer you might
be able to bypass the rectifiers for 60hz ac Tig, but you'd have no
control over the currrent... could get scary..?...

I thought Australia would have Lincoln dealers too? Do they crank the
price?

This discussion has me thinking about sellin my MillerMatic mig unit
and getting the Tig.

--- In CAD_CAM_EDM_DRO@egroups.com, diazden <diazden@o...> wrote:
> Joe Im in Australia
> mariano
>
>
> Joe Vicars wrote:
>
> > You can buy a brand new Lincoln Square Wave 175 for 1200
bucks. You could sell your DC TIG to offset the cost. IMHO the most
> > versatile welding machine ever made for the money!! (similar to
Miller EconoTIG, but cheaper)
> > The question is do you want to WELD aluminum or do you want
to BUILD your own TIG welder?
> > I don't think you will be able to beat the cost curve.
> >
> > diazden wrote:
> >
> > > Good evening Gordon
> > > I believe that I can use the original dc tig welder and make a
scr or big transistor
> > > box and plug it up in the welder output
> > > mariano
> > >
> > > Smoke wrote:
> > >
> > > > You are aware you may need put in a high frequency
transformer for this?
> > > >
> > > > Smoke
> > > >
> > > > -----Original Message-----
> > > > From: diazden <diazden@o...>
> > > > To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
> > > > Date: Thursday, November 30, 2000 11:46 PM
> > > > Subject: Re: [CAD_CAM_EDM_DRO] Please help
> > > >
> > > > >
> > > > >
> > > > >I know that this topic is not regarding the ones normally on
this list
> > > > >but can anyone provide me with a circuit diagram to convert
a dc tig welder
> > > > to
> > > > >ac to be able to weld aluminium to a maximum of 200 amps?
> > > > >thanks in advance
> > > > >mariano
> > > > >
> > > > >
> > > > >
> > >
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