Return-Path: Received: (qmail 16566 invoked from network); 6 Feb 2003 16:02:09 -0000 Content-Transfer-Encoding: 8bit Received: from netmail01.services.quay.plus.net (212.159.14.219) by mailstore with SMTP; 6 Feb 2003 16:02:09 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 1955 invoked by uid 10001); 6 Feb 2003 16:02:08 -0000 Received: from post.thorcom.com (193.82.116.70) by netmail01.services.quay.plus.net with SMTP; 6 Feb 2003 16:02:08 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18goTA-00051D-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 06 Feb 2003 16:01:44 +0000 Received: from [147.197.200.9] (helo=hestia.herts.ac.uk) by post.thorcom.com with esmtp (Exim 4.12) id 18goT9-000514-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Feb 2003 16:01:44 +0000 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 18goPZ-00072c-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Feb 2003 15:58:01 +0000 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 18goPX-0000tN-00 for rsgb_lf_group@blacksheep.org; Thu, 06 Feb 2003 15:57:59 +0000 Message-ID: <5.1.0.14.0.20030206154057.00ac78f0@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 06 Feb 2003 15:57:57 +0000 To: rsgb_lf_group@blacksheep.org From: "James Moritz" In-reply-to: <000c01c2cdf3$20d54530$ee9bfea9@oben> MIME-Version: 1.0 X-MailScanner: No Virus detected Subject: Re: LF: Coil Calculation Content-Type: text/plain; charset=us-ascii; format=flowed X-Spam-Status: No, hits=0.1 required=6.0tests=DEAR_SOMEBODY,IN_REP_TO,SPAM_PHRASE_00_01version=2.43 X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Dear Peter, LF group, I have used a simple DOS program coil.exe (runs OK in windows DOS box) which can be downloaded as coil02.zip from http://www.moshier.net/coildoc.html with reasonably accurate results for several types of coil. This implements one of several text-book formulae depending on what menu option you chose - it does loops, round and square solenoids, toroids etc. The Decca type basket-weave coil is probably best represented by a multi-layer circular solenoid (option 7). Don't forget to set the dimensions (option 11 - inches or cm). Do not expect very accurate results with this type of coil - all the formulae ignore distributed capacitance, which makes L frequency dependent. Multi-layer coils are obviously susceptible to this, which makes the apparent inductance higher. Cheers, Jim Moritz 73 de M0BMU