[Prev][Next][Index][Thread]
Re: Transformer basics
-
To: tesla@grendel.objinc.com, 1hosc@edge.net, KLINEDA@univscvm.csd.scarolina.edu, Pyrofish@aol.com, WMEYER@scientia.up.ac.za, bhaley@shore.net, brad.alheim@the-spa.com, coco@astroman.com, djz@dana.ucc.nau.edu, frerichs@zfe.siemens.de, froula@cig.mot.com
-
Subject: Re: Transformer basics
-
From: Esondrmn@aol.com
-
Date: Wed, 28 Feb 1996 12:04:54 -0500
-
>Received: from emout05.mail.aol.com (emout05.mail.aol.com [198.81.10.37]) by uucp-1.csn.net (8.6.12/8.6.12) with ESMTP id KAA07665 for <tesla@grendel.objinc.com>; Wed, 28 Feb 1996 10:11:45 -0700
In a message dated 96-02-27 22:13:16 EST, tesla@grendel.objinc.com writes:
>
>My questions are, has anybody wound their own before and if so could you
>offer
>me any practical advice such as ball park core weight for a 2-3 KVA xfrmr,
>any
>practical dimensions obtained and how the H.V. winding was wound for good
>insulation i.e. is it nessacery to varnish impregnate the windings ect.
>
>I have some calculations for determining core weight ect. But were taken
from
>a book published in 1950's and has probably been far exceeded by modern
>silicone irons used in cores ect. In fact i checked a couple of 440-240
>power transformers and their weight was a little over two thirds the value
>calculated for the weight of the iron core alone(and this was the total
>weight including copper and frames).
>
>
>*******************************************
>Ian Hopley ----> i_hopley@wintermute.co.uk
>Aberdeen
>Scotland
Ian,
I have rewound old transformers before, but for low voltage (battery chargers
and brute force power supplies) not for high voltage. Since I did not have
access to new cores, I searched surplus outlets, junkyards, etc. to find one
with the kva rating that I needed. Then I unwound all the secondaries and
counted the turns on some to calculate the turns per volt. Then wound on the
appropriate secondary wire. I would think you could find an old 2 or 3 kva
transformer and do the same thing, only with a lot more wire of a smaller
gauge. I don't think you need to do anything special like layering
insulation between windings. When you unpot neon sign transformers, they
just have miles of fine wire wound on layer after layer. I would give the
finished product a good varnishing - or submerge it in oil.
Ed Sonderman