Date: Mon, 1 Dec 2014 04:03:35 +1100 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: Matt Emmerton <matt@gsicomp.on.ca> Cc: freebsd-questions@freebsd.org, jd1008 <jd1008@gmail.com> Subject: RE: OT: UPS for FreeBSD Message-ID: <20141201033342.B85722@sola.nimnet.asn.au> In-Reply-To: <mailman.57.1417348801.66069.freebsd-questions@freebsd.org> References: <mailman.57.1417348801.66069.freebsd-questions@freebsd.org>
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Re: freebsd-questions Digest, Vol 547, Issue 7, Message: 6 On Sat, 29 Nov 2014 16:04:03 -0500 "Matt Emmerton" <matt@gsicomp.on.ca> wrote: > > 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. > > You might be interested to learn that many electrical utilities across the > world use DC transmission systems over hundreds or thousands of kilometers. > > http://en.wikipedia.org/wiki/List_of_HVDC_projects Indeed, there's a lot of it about. A broader treatment of HVDC is at: http://en.wikipedia.org/wiki/High-voltage_direct_current Particularly useful for undersea links, I'm familiar here with BassLink: http://en.wikipedia.org/wiki/Basslink which at 400kV / 500MW / 200km it's just a baby compared to the big ones, such as "The longest HVDC link in the world is currently the Xiangjiaba - Shanghai 2,071 km (1,287 mi), ±800 kV, 6400 MW link connecting the Xiangjiaba Dam to Shanghai, in the People's Republic of China" and "Early in 2013, the longest HVDC link will be the Rio Madeira link in Brazil, which consists of two bipoles of ±600 kV, 3150 MW each, connecting Porto Velho in the state of Rondônia to the São Paulo area, where the length of the DC line is 2,375 km (1,476 mi)." On the smaller end of the scale, there's lots of microgrids being built, mostly in the developing world, many of which are partly or largely DC. cheers, Ian From owner-freebsd-questions@FreeBSD.ORG Sun Nov 30 17:23:45 2014 Return-Path: <owner-freebsd-questions@FreeBSD.ORG> Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id A3E57C1A for <freebsd-questions@freebsd.org>; Sun, 30 Nov 2014 17:23:45 +0000 (UTC) Received: from mail-wi0-x229.google.com (mail-wi0-x229.google.com [IPv6:2a00:1450:400c:c05::229]) (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 37536B26 for <freebsd-questions@freebsd.org>; Sun, 30 Nov 2014 17:23:45 +0000 (UTC) Received: by mail-wi0-f169.google.com with SMTP id r20so24491778wiv.4 for <freebsd-questions@freebsd.org>; Sun, 30 Nov 2014 09:23:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:date:message-id:subject:from:to:content-type; bh=iih1OU8qQJaoaGBd8ObyKFLscwBnup+//w722qRgsTw=; b=D5Tbgm4DQ6c1YVlILf+SU7SPL+N4bB6SyaRHZQKSljR+bLU2iccB57ZTxdBzgO5JR6 9HvgBcSnb0ygvxIA3C+UdS/GfkcGiefY/zqtip/TGxoNccsQxhgpA5InxzKWRXXsJXdQ L0ILhhyu43hnBX0yCHddh+FwhMOtb5ERnisIQdKyiDvxYPpy2QxuRYaIDaSRrPGuRRM6 JxnjJ/9rDi4OP0NUKgbctZ2vBCNDmuOdUep9PlBYf/gzUbS9wzdxZkBPoh8NYQPrjkz4 3GBT4wcrLQP4GFeAuCSzMO5sTceh+3Wc0fKILOILHkFkUq1U+OSivh5QnfwG7G++IiX6 OtXw== MIME-Version: 1.0 X-Received: by 10.180.101.200 with SMTP id fi8mr77641394wib.77.1417368223730; Sun, 30 Nov 2014 09:23:43 -0800 (PST) Sender: fluca1978@gmail.com Received: by 10.194.85.43 with HTTP; Sun, 30 Nov 2014 09:23:43 -0800 (PST) Date: Sun, 30 Nov 2014 18:23:43 +0100 X-Google-Sender-Auth: I7C3uSmnJpLBSukCNpyB1hroSKk Message-ID: <CAKoxK+780cv7uC6GJtcQhQCdy1r6HOqTFQfchrVMXWF7ENf5dw@mail.gmail.com> Subject: suggestion for an all-in-one with multi page scanner From: Luca Ferrari <fluca1978@infinito.it> To: freebsd-questions <freebsd-questions@freebsd.org> Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions <freebsd-questions.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-questions>, <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions/>; List-Post: <mailto:freebsd-questions@freebsd.org> List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, <mailto:freebsd-questions-request@freebsd.org?subject=subscribe> X-List-Received-Date: Sun, 30 Nov 2014 17:23:45 -0000 Hi all, Christmas is approaching and I'd like a suggestion for an all-in-one device with multipage scanner. In particular I'm interested in the printer and scanner, I don't need the fax device. And of course it is supposed to fully work with FreeBSD. Any idea? Thanks, Luca
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