Re: Transformer core

i rewound a core of similar size for ballasting my pig...
altho i feel Dr Rez can answer this one much better than I but i will
give you my experiences ...

i ground out the welds and rewound the core with #10 solid copper
insulated ..    after rewelding the I back on I tested it on 120 V with
a current draw of 6 amps ... but here are the details ...

there are 150 turns and there is also an air gap at the center leg to
the I bar of .060 "  ( increased reluctance e.g. more current draw) the
ends ( outside legs) are flush ( minimal gap ) to the I bar.  when the
unit is used with the pig there is a current draw of 20 - 25 amps (
seems to surge a bit ) the unit gets warm but not enuf to damage the
insulation on the windings.  btw  im using 240 on the pig input ..

Scot D 

Tesla List wrote:
> Original Poster: "Matt Behrend" <electronxlc-at-earthlink-dot-net>
> Hi all,
> I have a large transformer core that I want to wind for my inductive
> ballast - 13mH.  It must handle 3kVA without saturating, so could
> some of the transformer experts tell me if my core is large enough,
> and minimum number of turns required?
> Overall dimensions are 7.5" x 6.25" x 2.5"
> cross sectional area 1.25" x 2.5" on perimeter sides and 2.5" x
> 2.5" in center leg of the El  shape.
> This is from a 1kVA Topaz isolation transformer, but the size of the
> core seems like it can take much more power.
> Matt Behrend