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Re: Transformer cores



Tesla List wrote:
> 
> Original Poster: "Gregory R. Hunter" <ghunter-at-enterprise-dot-net>
> 
> Alfred & Max,
> 
> I've often wondered about "transformer iron" as well.  I think it contains
> lots of Silicon.  It magnetizes very easily in the presence of a magnetic
> field, but demagnetizes quickly when that field is removed--for low
> hysteresis loss.  Many kinds of cheap wire made of poor quality, high
> silicon steel might approximate transformer iron.  I'm thinking of Alfred's

The high silicon content also increases the DC resistance of the iron,
which, in turn, reduces eddy current losses. Imagine a solid bar of iron
as your core. Now imagine just the outer skin of that bar. Looks like a
single turn secondary, doesn't it.  Hence, laminations (not a shorted
turn), and high resistivity materials.

The silicon also raises the maximum field before the iron saturates, as
well as making the coercivity low. This is also a good thing, because it
allows you to use fewer turns for the same voltage.
> 
-- 
Jim Lux                               Jet Propulsion Laboratory
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