RE: transformer cores

["Duke, Ronn (CCI-San Diego CCC)" <Ron.Duke-at-xxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Chris,
I think that transformers have square cores because square cores afford the
best efficiency. If you have ever unpotted a NST, you will notice that the
cross section of the center of the core is rectangular instead of square. (
I think its because of space limitations). As for another reason is the ease
of manufacture. If you have ever taken apart a standard transformer E and I
core, and put two ' E' laminations together end to end (E's pointing toward
each other), you will notice that the 'I' sections will fit perfectly in the
long spaces of the two 'E' cores. This will give you one square piece of
sheet metal with no cut off waste. Cores are stamped out of huge rolls of
silicon steel sheet metal thousands at a time. 

Keep on coilin'

Dr. Evil

	-----Original Message-----
	From:	Tesla list [SMTP:tesla-at-pupman-dot-com]
	Sent:	Wednesday, November 15, 2000 6:26 AM
	To:	tesla-at-pupman-dot-com
	Subject:	Re: transformer cores

	Original poster: "BunnyKiller" <bigfoo39-at-telocity-dot-com> 

	Tesla list wrote:

	> Original poster: CTCDW-at-aol-dot-com
	>
	> Hello all..
	>
	> just a curious question.. Is there an easily explainable (hah)
reason that
	> the rectangular or square transformer core has been adopted?
induction coils
	> generally have a cylidrical or square (cross section) iron core
inside...in
	> an induction coil, the primary is usually inside the
secondary..what is
	> gained when they are on opposite sides of a square core?
	>
	> Chris

	Hi Chris...

	you have a good one there...   as far as the square or rectangular
core assys.
	its easier to manufacture the multitude of plates that comprise the
total core
	all as the same size. the reason why the primary is normally on the
inside of
	the windings is that the flux produced by the primary is more
concentrated upon
	the core allowing better field effect. the induced field effect is
then
	transfered to the secondary with minimal loss. if the primary was on
the
	"outside" windings, you would see less "transfer" of the field
effect to the
	core and more inductive effects upon the secondary which would
reduce the
	effectiveness of the transformer.

	Ha ! college does have its merits  ;)

	Scot D