From owner-freebsd-questions@FreeBSD.ORG Sat Nov 29 20:22:20 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 26610326 for ; Sat, 29 Nov 2014 20:22:20 +0000 (UTC) Received: from mail-pd0-x230.google.com (mail-pd0-x230.google.com [IPv6:2607:f8b0:400e:c02::230]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id EC68012C for ; Sat, 29 Nov 2014 20:22:19 +0000 (UTC) Received: by mail-pd0-f176.google.com with SMTP id y10so8404517pdj.7 for ; Sat, 29 Nov 2014 12:22:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:subject:references :in-reply-to:content-type:content-transfer-encoding; bh=zQ2lOnXaCfMv0PqcjD5eW0ZbenBcfVp5IsBxrtYw7LM=; b=V8MfI9cMFTkk7H5RNU6MX/RinjBlg02eJeume1T0pQss2sj+tfQiglq6Gjc+dyfgNA Bq5zj59zdoXsIp6XW2GIZ+sE3XVDWfgv7cMSGHxQH0DmqOGcjuduXpAzDrjxEXE3Fyqu p87gWWw8TBDHQbsLMbmeU6I5nDKMNmd5Jwi8DKSVQHDkCB5PThaIzxtS6LWu9DVGOWHo rCmydQqCXvaedIePXHtHCmviUXpDpngLnhngeXx+rm94wFldlGUmRSR+Gh8Y4EcZj2JH yA+NKCd/toW5UUlTz5uAShA3Dkyx35Mg+ZdKJ/f9a1QoNqihG3+U/Ro/He6eGoMKh3dk 8kgw== X-Received: by 10.66.255.100 with SMTP id ap4mr83565523pad.133.1417292539332; Sat, 29 Nov 2014 12:22:19 -0800 (PST) Received: from localhost.localdomain (76-218-80-47.lightspeed.irvnca.sbcglobal.net. [76.218.80.47]) by mx.google.com with ESMTPSA id op10sm5876430pbc.90.2014.11.29.12.22.18 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 29 Nov 2014 12:22:18 -0800 (PST) Message-ID: <547A2ADD.4020106@gmail.com> Date: Sat, 29 Nov 2014 13:21:49 -0700 From: jd1008 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: freebsd-questions@freebsd.org Subject: Re: OT: UPS for FreeBSD References: <54777AB1.9010800@bluerosetech.com> <54779629.302@bluerosetech.com> <5478BD4F.7020306@yahoo.com> <5478BEE6.30308@bluerosetech.com> <5478CC08.9090307@yahoo.com> <20141128204722.561f948e@archlinux> <5478F16A.80605@yahoo.com> <54791d3a.w/pI0kak03d+3nKC%perryh@pluto.rain.com> <547937AB.1030706@radel.com> <20141129121211.014cb856@X220.alogt.com> <547A24F7.6070100@bluerosetech.com> In-Reply-To: <547A24F7.6070100@bluerosetech.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 29 Nov 2014 20:22:20 -0000 On 11/29/2014 12:56 PM, Darren Pilgrim wrote: > On 11/28/2014 8:12 PM, Erich Dollansky wrote: >> Real high voltage transmission >> lines using DC make sense. > > Someone already tried that. It doesn't work. The conductors have to > be impractically large to get a useful amount of current, and the > distance loss is so high you can't build even a metro grid with it, > let alone a regional grid or the long-distance transmission systems we > use now. > __ That is correct Darren - Long distance transmission, even for a scan few miles is impractical with DC. But if I had the cash, I would design and build my home with DC current only. No AC. I do not want to go into the reasons, and thus generate a lot of noise about it :)