Re: Transformer cores

To: tesla-at-pupman-dot-com
Subject: Re: Transformer cores
From: Teslaman-at-aol-dot-com (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Sun, 08 Nov 1998 18:54:12 -0700
Approved: terryf-at-verinet-dot-com

In a message dated 11/8/98 3:58:53 PM Central Standard Time, tesla-at-pupman-dot-com
writes:

> 
>  I have been reading some postings from one of the list members in
>  Australia who has built his own home built pig. I would like to know if
>  anyone knows were to find large laminated iron cores? This would give
>  you the flexibility to wind a transformer to whatever voltage that you
>  like and would be a great learning experiance as well.

>  
  Max

  He did do a great job on the transformer and oil filled case, very neatly
done.  As to transformer cores here in the USA, they are everywhere.  An
electrical surplus shop may have many dry 3-phase power transformers that can
be re-stacked and wound for single phase.  Most of these are 120/240--240/480
up to around 2400 volts.  I have found they like to get rid of odd ball
voltage transformers cheap, like 600 volt units and any transformer that is
not complete (like a panel missing).  Even those 60 amp 12 volt battery
chargers have excellent cores for rewinding.

  If you like a challenge, try a distribution transformer rewind shop, they
scrap pigs for pennies on the dollar and some times are just free (especially
240/7200 volt pigs).
  The cores are "c" shaped and each lamination is a different size, each one
fits over the next one for one side of the core, then two of them pass through
the windings to complete the transformer.

  The best thing about rewinding transformers is some times the low voltage
winding can be left alone, and only a high voltage winding wound over the
original low voltage
(120/240) winding.  If not, then most times the wire can be reused, large gage
copper primary wire is not cheap to buy!

Happy rewinding

Kevin E.