Return-Path: Received: from rly-da06.mx.aol.com (rly-da06.mail.aol.com [172.19.129.80]) by air-da07.mail.aol.com (v120.9) with ESMTP id MAILINDA071-a75472de55dce; Sun, 04 Nov 2007 10:29:40 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da06.mx.aol.com (v120.9) with ESMTP id MAILRELAYINDA065-a75472de55dce; Sun, 04 Nov 2007 10:29:34 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1IohPM-0000wo-R2 for rs_out_1@blacksheep.org; Sun, 04 Nov 2007 15:29:04 +0000 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1IohPM-0000wf-Ag for rsgb_lf_group@blacksheep.org; Sun, 04 Nov 2007 15:29:04 +0000 Received: from mailout.toya.net.pl ([217.113.224.27] ident=postfix) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1IohPI-0005Wy-Ek for rsgb_lf_group@blacksheep.org; Sun, 04 Nov 2007 15:29:04 +0000 Received: from localhost (unknown [192.168.120.26]) by lazir.toya.net.pl (TOYAnet MailServer) with ESMTP id 9717C8C21E for ; Sun, 4 Nov 2007 16:28:58 +0100 (CET) X-TOYA-AV: AntyVir-Skaner at toya.net.pl Received: from lazir.toya.net.pl ([192.168.120.25]) by localhost (antyvir.toya.net.pl [192.168.120.26]) (amavisd-new, port 10024) with ESMTP id oqUOQi+6yBXL for ; Sun, 4 Nov 2007 16:28:56 +0100 (CET) Received: from [217.113.234.35] (lazir [217.113.224.3]) by lazir.toya.net.pl (TOYAnet MailServer) with ESMTP id 13C3E8C061 for ; Sun, 4 Nov 2007 16:28:57 +0100 (CET) Message-ID: <472DE539.2000201@toya.net.pl> Date: Sun, 04 Nov 2007 16:28:57 +0100 From: =?UTF-8?B?UGlvdHIgTcWCeW5hcnNraQ==?= User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.7.2) Gecko/20040804 Netscape/7.2 (ax) X-Accept-Language: en-us, en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <000701c81ede$3af050e0$1ae4fc3e@g3kev> In-Reply-To: <000701c81ede$3af050e0$1ae4fc3e@g3kev> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: CLASS D and E Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 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-AOL-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : X-Mailer: Unknown (No Version) hamilton mal wrote: >Hi all >Class D and E amplifiers are supposed to give around 80/90 % efficiency. Has >anyone actually achieved these figures. It seems anything above 60% is hard >to arrive at using normal coils/capacitors. > >73 de Mal/G3KEV > > > > Hi Mal, LF group iin my design of class E 137 kHz PA using DC power of 27V and I = 6A i got 220 V(p-p) into 48 Ohm test load so this yields around 78% efficiency. i've used polyprop capacitors and PVC pipes for all windings. all necessary calc. were made using Nathan Sokal's equations in the QEX Jan/Feb 2001 magazine. also I HAVE TO mention the work of Alan, G3NYK; Mike, GW4HXO and Finbar EI0CF presented on Alan web site. i've made a great use of their work and experience. thank you :) 73, peter,sq7mpj