Return-Path: X-Spam-DCC: paranoid 1356; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id t9VIjjHq012348 for ; Sat, 31 Oct 2015 19:45:45 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Zsb6C-0005vz-3v for rs_out_1@blacksheep.org; Sat, 31 Oct 2015 18:41:56 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Zsb6B-0005vq-QX for rsgb_lf_group@blacksheep.org; Sat, 31 Oct 2015 18:41:55 +0000 Received: from mail-wm0-f52.google.com ([74.125.82.52]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1Zsb57-00036Z-7T for rsgb_lf_group@blacksheep.org; Sat, 31 Oct 2015 18:41:54 +0000 Received: by wmll128 with SMTP id l128so33387097wml.0 for ; Sat, 31 Oct 2015 11:40:35 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=11YezKO92hsg4WVqA9bTkqEi98qgyy4rpEFet30fh9U=; b=LfD9lbpNaMvLz6X2kJ2L0dz8Bkj0p167FDdyF5d1MonqvnuoM5g5I1r7f0xaWbICTZ VU1G/UBfX/U7noNctDmJ21xKNDqd3cHGEUOcHldpYi0nVkRRB7FfRmgc65vZ/ANPAvRV bDONE+WTVopaabXn1YImp0neDJ+MEjz/gJ3ccypVW2IADmBEUEbrFzli2pOjEaIaFpx0 R2uNEMwLeXzjnZboXAUYgSeqBr76hDxkMINlu1gA3qI6tDoQGS7ZeKOWfLTVq8ApwM3E t0NjtB0MSATrtEafWbmcvef6iFYLqmbR52qRZHlDXmKmrO2lT9M7zfN5kEezH7r+KAPU wBaQ== MIME-Version: 1.0 X-Received: by 10.28.174.195 with SMTP id x186mr4974282wme.87.1446316835177; Sat, 31 Oct 2015 11:40:35 -0700 (PDT) Received: by 10.28.183.139 with HTTP; Sat, 31 Oct 2015 11:40:35 -0700 (PDT) In-Reply-To: References: <1887849276.20151030143118@chriswilson.tv> <5633B50A.5030903@posteo.de> <5633D56C.20659.23BE4D8@mike.dennison.ntlworld.com> <316685691.20151031121552@chriswilson.tv> Date: Sat, 31 Oct 2015 18:40:35 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 4f449c45f7b1894a9195a328eedaeb30 Subject: Re: Re[2]: LF: Zmag of 45.6 Ohms OK, or should I try for better? Content-Type: multipart/alternative; boundary=001a11442822318be805236ae18e 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4736 --001a11442822318be805236ae18e Content-Type: text/plain; charset=UTF-8 Not too many turns, copper losses can become significant. Use the oft quoted formula on this Group Vrms = 4.44.F.N.A.B (All SI units) Keep B below 0.1 Tesla, 0.08T is ample Andy G4JNT On 31 October 2015 at 18:30, Clemens Paul wrote: > Hi Chris, > > >I have a 3C90 core spare and will wind a 1 : > >1 transformer for now, just for isolation. How many turns should I use > >for best efficiency? > > It's primarily not a matter of efficieny but of flux density in the core > (->heating ,saturation) > What is the size of the core and your power level? > Generally I would wind as much turns as feasible on the core to keep flux > as low as possible. > For best efficiency and low stray inductance tight coupling of the primary > and secondary winding is essential. > > 73 > Clemens > DL4RAJ > > >-----Original Message----- > >From: owner-rsgb_lf_group@blacksheep.org > >[mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Chris Wilson > >Sent: Saturday, October 31, 2015 1:16 PM > >To: Mike Dennison > >Subject: Re[2]: LF: Zmag of 45.6 Ohms OK, or should I try for better? > > > > > --001a11442822318be805236ae18e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Not too many turns, copper losses can become significant.<= div>
Use the oft quoted formula on this Group=C2=A0

Vrms =3D 4.44.F.N.A.B =C2=A0(All SI units)=C2=A0
= Keep B below 0.1 Tesla, 0.08T is ample

Andy =C2=A0= G4JNT

= On 31 October 2015 at 18:30, Clemens Paul <cpaul@gmx.net> wrote:=
Hi Chris,

>I have a 3C90 core spare and will wind a 1 :
>1 transformer for now, just for isolation. How many turns should I use<= br> >for best efficiency?

It's primarily not a matter of efficieny but of flux density in the cor= e
(->heating ,saturation)
What is the size of the core and your power level?
Generally I would wind as much turns as feasible on the core to keep flux a= s low as possible.
For best efficiency and low stray inductance tight coupling of the primary = and secondary winding is essential.

73
Clemens
DL4RAJ

>-----Original Message-----
>From: owner-rsgb_= lf_group@blacksheep.org
>[mailto:owner-rsg= b_lf_group@blacksheep.org] On Behalf Of Chris Wilson
>Sent: Saturday, October 31, 2015 1:16 PM
>To: Mike Dennison
>Subject: Re[2]: LF: Zmag of 45.6 Ohms OK, or should I try for better? >



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