Re: low-cost 1800-amp heating source

On Thu, 02 Aug 2007 15:16:46 GMT, Glen Walpert <gwalpert@xxxxxxxxxx>
wrote:

On Thu, 02 Aug 2007 03:38:34 -0700, Winfield <winfieldhill@xxxxxxxxx>
wrote:

Actually, why can't the two transformer primary windings be
in parallel? That'd reduce the copper resistance. And
L(leak) for that matter, right? Editing Tony's drawing:

AC high + Pri - Load current
--+-----------////////-------+--->---,
| T1 ======== | |
| DC --+---////////---, | |(
| | + Sec - | | |( L(leak)
| +_|_ | | |(
| --- | | |
| | + Sec - | | / Win's Load.
| DC --+---////////---' | \ Rload
| T2 ======== | /
'-----------////////-------' |
+ Pri - AC low

OK, now I see that Tony took advantage of a series primary
connection to use transformers with half the primary voltage
rating. Hah, it appears there's no free lunch.

It appears to me that the DC bias current can only saturate the core
for one half of the input cycle; the half where the magnetic fields
add rather than subtract, and that the original series configuration
had the fields add for both halves of the power cycle in one
transformer or the other, for symnetrical operation. The parallel
circuit would appear to deliver a bunch of DC to the load when
saturated. Good test of a Spice transformer model perhaps :-).

Oops! Never mind, I looked at that drawing twice and still saw it
wrong :-(.
.

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