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Re: Transformer Questions
> Original Poster: "Mad Mike" <mglass-at-netusa1-dot-net>
>
>
> Hi all
> I need the advice of a transformer guru. I have recently aquired 4
> transformer cores which have a short U and a long U with ground surfaces to
> mate the two halves together. They were originally held together with 2 SS
> bands and a crimp. I plan to hold them together with a pair of SS hose
> clamps. The "window" is 7 1/4" x 2 3/4". the legs are 1 3/4" x 2 1/2". Each
> unit weighs about 30 lbs. I've run the numbers through the formulas and my
> plan is to wind 2 transformers of 15kv (2 - 7500 vac windings in series) -at-
> 2500 watts each then run the two units in parallel for 5000 watts total.
> (I'm using
> #10 wire for the primaries and #30 wire for the secondaries). Some
> questions: Most cores I have seen are fairly square, these are pretty long,
> will reluctance be a problem? What would be the best setup for TC use, the
> primary on one leg and the secondaries on the other or a primary and a
> secondary on each leg? The transformers will of course be run in transformer
> oil, how much wattage could one safely wring out of this design beyond 5000
> watts? As to the cores themselves, what would they cost if I didn't have a
> free source? Any input is welcomed.
> Thanks
> Mike KB9NZQ
Hi Mike,
If you wind the primary on one leg and the secondary on the
other there should be a significant amount of leakage inductance
present. You may well find that you can use the transformer without
having to ballast it. I use a smaller transformer wound the same way
for a coil running straight from the wallplug. It might pay to wind a
couple of quick coils for both modes to allow measurement of this so
you can decide which you prefer.
Malcolm