Return-Path: Received: (qmail 8391 invoked from network); 11 Aug 2002 00:42:32 -0000 Received: from marstons.services.quay.plus.net (212.159.14.223) by mailstore with SMTP; 11 Aug 2002 00:42:32 -0000 Received: (qmail 15231 invoked by uid 10001); 11 Aug 2002 00:46:58 -0000 Received: from post.thorcom.com (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 11 Aug 2002 00:46:58 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17diVt-00001p-00 for rsgb_lf_group-outgoing@blacksheep.org; Sun, 11 Aug 2002 03:31:29 +0100 Received: from mta203-rme.xtra.co.nz ([210.86.15.146]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17diVr-00001k-00 for rsgb_lf_group@blacksheep.org; Sun, 11 Aug 2002 03:31:27 +0100 Received: from mta1-rme.xtra.co.nz ([210.86.15.143]) by mta203-rme.xtra.co.nz with ESMTP id <20020811003842.OROX2461.mta203-rme.xtra.co.nz@mta1-rme.xtra.co.nz> for ; Sun, 11 Aug 2002 12:38:42 +1200 Received: from xtr743187 ([219.88.42.94]) by mta1-rme.xtra.co.nz with SMTP id <20020811003842.CNDE25014.mta1-rme.xtra.co.nz@xtr743187> for ; Sun, 11 Aug 2002 12:38:42 +1200 Message-ID: <001f01c240d0$2ff5ac40$5e2a58db@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <17chZQ-13Oc8eC@fwd05.sul.t-online.com> <5.1.0.14.0.20020808182124.00b0a1b0@gemini.herts.ac.uk> <005701c23f26$3e24c720$162565d5@oemcomputer> <17cwaH-07Lv5UC@fwd11.sul.t-online.com> <00ba01c23f35$04d85c20$da2565d5@oemcomputer> <005001c24075$634ae840$788ec9c8@local> <3D55695C.4999366C@usa.net> Subject: LF: Re: An Excel sheet to play with toroids Date: Sun, 11 Aug 2002 12:42:47 +1200 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Alberto, An excerpt from your message: > In my opinion it contained an error, as it used the same > formula involving AL, both with ferrite toroids and > iron-powder toroids. Amidon gives two different > formulas for the two cases. I corrected it, and added > a couple of other, maybe useful, functions. I think you'll find that each Amidon formula is "different" by scaling factor only. Inductance is still "turns squared" and scaling coefficients and turn reference numbers are selected to arrive at convenient values in millihenries for ferrites (generally high Al values) and microhenries for powdered iron (generally low Al values). 73, Bob ZL2CA