Re: Building a bridge ...

On Tue, 22 Aug 2006 05:18:53 -0500, Snag <snagone@xxxxxxxxxxxxx> wrote:
Ignoramus4235 wrote:
On Mon, 21 Aug 2006 22:14:14 -0500, Snag <snagone@xxxxxxxxxxxxx>
wrote:
Rectifier , that is . Scored four 275 amp/600 volt units for a net
cost of ten bucks each (shipping included) .
Got the circuitry and heat sinks figgered out ... but I recall
some talk in a recent thread about inductors to stabilize the arc .
Would I be safe in assuming the unit needs a fairly large (2X2X6 ?)
laminated core with a winding capable of carrying the max current
the welder is rated for ? My question is , how many turns is this
thing gonna need ? Is field density a linear function ? Ten turns ?
Thirty ?

I can make and email you pictures of inductor in my Hobart CyberTig,
rated for 200 amps.

I'm going to build a fullwave bridge , shouldn't really have that
much ripple

Are you on single phase (you talk about 4 diodes, not six as there
would be in a three phase bridge). If so, your ripple will be as bad
as it gets.

. I had some training in electronics a few years ago (a few , he sez
...) and understand the theory of inductive current stabilization .
Just don't have the math ...

I can send you a picture of my inductor, if you want.

i

I'd like that pic - and don't worry too much about file size , we gots DSL
here . I meant that voltage/current ripple will be much less than if I used
just one diode as a halfwave bridge . I wish I had 3 phase , but in a
residential area , they can't/won't supply it . And I got no room for a
phase converter ...
I may do like Carl and make a few turns around a core with some copper
tube I have . I remember Dad (he was an ET , and a very smart man) building
an arc stabilixer for a neighbor's engine powered welder , it was a bar of
conductor bent into multiple "s" curves about a foot or so long mounted on
insulators and wired in series . I recall the neighbor was amazed at how
well it worked . I wish Dad were still around ...


OK, I will try to do it tonight. I can tell you now that this inductor
is about 7x8x7 inches and is probably quite heavy.

i

.

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