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Message-ID: <004e01c94a9c$dddbe860$0900a8c0@AM>
From: "Alan Melia" <alan.melia@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
References: <001e01c94a77$cc1fa780$a402a8c0@Inspiron>
Date: Wed, 19 Nov 2008 23:15:14 -0000
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Subject: LF: Re: 3C85/90 Toroids
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Lee, I think the 3C85s were made by Philips and I susppect they have sold of
that line look under Neosid, and Epcos (though my link to the latter does
not seem to work now, but it is a couple of years since I was searching
their site. Just look for the right sized core in a material with a
permiability of around 4000, you can get higher values but I believe these
may be a bit more lossy. The other trick is to look up the "turns per mH"
(or uH) then wid a few turns on an unknown core and see what the inductance
comes out at. I bout a couple of massive cores at Donning a couple of years
back that had brown and blue mains wire wrapped round them. They were about
6in diam and were brilliant for transformers. The 56uH that was refered to
is for the LPF and inductors for these should never be wound on ferrite, low
permiability iiron dust possibly but air cored on a 38mm white waste pipe is
by far the best. Just make sure the coil axes are orthogonal if they are not
screened as the stray fields are much higher than from toroids.

Some ideas here
http://www.alan.melia.btinternet.co.uk/toroids.htm#ferrite%20toroids

Alan G3NYK


----- Original Message -----
From: "Lee Hudson" <hudsonville@btinternet.com>
To: <rsgb_lf_group@blacksheep.org>
Sent: Wednesday, November 19, 2008 6:51 PM
Subject: LF: 3C85/90 Toroids


> Hi,
>
> Any suggestions for suppliers of Toroids made from 3C85/90 material rather
> than stripping down old SMPS?
>
> 73,
> Lee
> M0LMH
>
>