Return-Path: Received: from rly-mc11.mx.aol.com (rly-mc11.mail.aol.com [172.21.164.95]) by air-mc01.mail.aol.com (v124.15) with ESMTP id MAILINMC013-da24a9591aa218; Wed, 26 Aug 2009 15:49:23 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mc11.mx.aol.com (v124.15) with ESMTP id MAILRELAYINMC112-da24a9591aa218; Wed, 26 Aug 2009 15:49:01 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MgOTS-000495-Le for rs_out_1@blacksheep.org; Wed, 26 Aug 2009 20:48:02 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MgOTS-00048w-9f for rsgb_lf_group@blacksheep.org; Wed, 26 Aug 2009 20:48:02 +0100 Received: from smarthost2.mail.uk.easynet.net ([212.135.6.12]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1MgOTL-0006Jr-EO for rsgb_lf_group@blacksheep.org; Wed, 26 Aug 2009 20:47:57 +0100 Received: from bb-87-82-24-91.ukonline.co.uk ([87.82.24.91] helo=[192.168.0.4]) by smarthost2.mail.uk.easynet.net with esmtp (Exim 4.69) (envelope-from ) id 1MgOTK-0002lK-U3 for rsgb_lf_group@blacksheep.org; Wed, 26 Aug 2009 20:47:55 +0100 Message-ID: <4A959575.1050502@ukonline.co.uk> Date: Wed, 26 Aug 2009 21:05:09 +0100 From: Peter Dodd User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <002a01ca2674$fbdbd370$0301a8c0@mal769a60aa920> <4A9588FA.5030606@telia.com> In-Reply-To: <4A9588FA.5030606@telia.com> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: psu Content-Type: text/plain; charset=ISO-8859-1; 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-Mailer: Unknown (No Version) Hi Johan, What an interesting solution. British airborne radars used 80VAC at 2000Hz to reduce the size and weight of the PSU components, quite a consideration in systems like H2S. Peter, G3LDO > > since you mentioned 400Hz (I meant cycles per second of course, > sorry...) I assume that your are about to bring some wartime airborne > equipment back to life. > > If efficiency is not at highest priority, take an audio amplifier, > capable of delivering >15W with a good margin, feed a 400Hz sine wave > into its input and connect a 230V => some_low_voltage transformer > "backwards" to the amplifier's output. Adjust the volume control to get > 115V at the xfmr's output. > > 73 > Johan SM6LKM > > mal hamilton wrote: > >> Need a psu that gives 115v - 15w output at 400 cps. Input could be >> anything ie mains ac or dc. >> If nothing is available I have a plan to divide a 4Mhz xtal down to 400 >> cps then amplify/step up to give 115v/15w >> 73 de mal/g3kev >> >> > > > >