Envelope-to: dave@picks.force9.co.uk Delivery-date: Tue, 25 Oct 2005 20:39:28 +0100 Received: by pih-mxcore18.plus.net with spam-scanned (PlusNet MXCore v2.00) id 1EUUdr-0002v8-Fj for dave@picks.force9.co.uk; Tue, 25 Oct 2005 20:39:27 +0100 Received: from post.thorcom.com ([193.82.116.20]) by pih-mxcore18.plus.net with esmtp (PlusNet MXCore v2.00) id 1EUUdr-0002um-8e for dave@picks.force9.co.uk; Tue, 25 Oct 2005 20:39:27 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1EUUcd-0000Sj-Tj for rs_out_1@blacksheep.org; Tue, 25 Oct 2005 20:38:11 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1EUUcd-0000Sa-Fl for rsgb_lf_group@blacksheep.org; Tue, 25 Oct 2005 20:38:11 +0100 Received: from sp0235.sc1.cp.net ([64.97.136.235] helo=n068.sc1.cp.net) by relay2.thorcom.net with esmtp (Exim 4.51) id 1EUVcA-0006fx-RM for rsgb_lf_group@blacksheep.org; Tue, 25 Oct 2005 21:41:47 +0100 Received: from l8p8y6 (62.252.228.224) by n068.sc1.cp.net (7.0.038) id 435B0E49000953F0 for rsgb_lf_group@blacksheep.org; Tue, 25 Oct 2005 19:38:09 +0000 Message-ID: <009801c5d991$2413f460$e0e4fc3e@l8p8y6> From: "hamilton mal" To: rsgb_lf_group@blacksheep.org References: <1811814855.20051024154952@sibru.ru> <000201c5d8e8$6574e8a0$5611f4cc@p1i5f0> <016a01c5d8e6$8baee5e0$54ecfea9@server> Date: Tue, 25 Oct 2005 16:11:48 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4807.1700 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Subject: LF: Re: Toroid winding question Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-PN-SpamFiltered: by PlusNet MXCore (v2.00) ----- Original Message ----- From: "J. B. Weazle McCreath" To: Sent: Monday, October 24, 2005 11:01 PM Subject: LF: Toroid winding question > Hello LFers, > > How critical is the spacing between the windings and the core material when > winding a toroidal transformer? I have a core taken from a television > flyback > transformer that I'd like to experiment with using different winding > techniques. > To simplify things, I was thinking of putting the windings onto bobbins that > could quickly be slipped on and off of the core. Would I be OK with using > a bobbin with 1/8 inch (3 mm) wall thickness or should I look for something > with a thinner wall? Any and all comments welcome. > > 73, J.B., VE3EAR - VE3WZL > Solar and wind powered > EN93dr I use these cores, which are mostly 3C material, some are marked. My approach, keep the two halves of the core as tight together as possible, no gap, then wind around the whole perimiter firstly with the winding that requires most turns and over wind this with the heavier guage winding of least turns eg This method is not as convenient as using two bobbins one for prim and one for sec but it works well, distribute the turns equally on each of the 4 sides and keep the same sense for both windings. The two halves need to be tightly clamped with a metal bracket, use the original bracked that comes with the transformer. I tried using plastic ties but you cannot get these tight enough. 73 de Mal/G3KEV > > >