From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailhost.cotse.com (mail.cotse.net [66.203.85.58]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 4BC0A21F34D; Sat, 28 Jun 2014 09:16:35 -0700 (PDT) Received: from out.packetderm.com (out.packetderm.com [66.203.85.62]) by mailhost.cotse.com (8.14.8/8.14.5) with ESMTP id s5SGGW3q039827 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 28 Jun 2014 12:16:32 -0400 (EDT) (envelope-from cerowrt@decoy.cotse.net) Received: from localhost (localhost[127.0.0.1]) (authenticated bits=0) by smtp (5.7.4/5.7.4) with ESMTP id s5SGGWDj067417 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Sat, 28 Jun 2014 12:16:32 -0400 (EDT) (envelope-from cerowrt@decoy.cotse.net) Message-ID: Date: Sat, 28 Jun 2014 12:16:30 -0400 From: Joseph Swick MIME-Version: 1.0 To: cerowrt-devel@lists.bufferbloat.net, bloat@lists.bufferbloat.net References: <53A9D92B.7010603@hp.com> <16169.1403645906@sandelman.ca> <8aeaf238-4612-410e-8d07-38159873ea17@reed.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: [Cerowrt-devel] =?utf-8?q?Low_Power_UPSes_=28Was=3A_Re=3A__=5BBlo?= =?utf-8?q?at=5D__Dave_T=C3=A4ht_quoted_in_the_ACLU_blog=29?= X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 Jun 2014 16:16:35 -0000 On 06/28/2014 12:28 AM, Dave Taht wrote: > Pretty sure (haven't booted it yet) the parallella (which is smaller > than a drive), > can do it in under a 2 watt, and if it doesn't do gigE now, it'll do > it after I get through > with it - but it lacks a sata port, and usb is only 2.0, so it might > not drive gigE > from a nas perspective. (It kind of bugs me that most of the tiny boards are in > the altoids form factor, rather than the 2.5 inch drive form factor) > > So I go back to my original point in that, once you have fiber to the business, > for most purposes in a small business or startup or home - who needs > to co-lo in a data center? > You can have a tiny wart on the wall do most of the job. And that's > today. In another > year or so we'll be over some more tipping points. > > One thing that does bug me is most UPSes are optimized to deliver a large > load over a short time, a UPS capable of driving 5 watts for, say, 3 days is > kind of rare. > I think this is something that's in need of a new approach/disruption. For low power devices like NUCs and RasPi servers, running them off of a traditional UPS is hugely waste-full, since you're going from your Line voltage (120VAC or 240VAC in many places) to 12 or 24VDC (Or 48VDC for a bigger UPS). Then when the UPS has to kick in, it converts the battery voltage back to your line voltage. A better approach would be to have a UPS that had a good intelligent charger for your deep-cycle type battery that coming off the battery, you kept it at the correct DC level for your NUC or Raspi. Which for many of these devices is 5 or 12VDC. So in a sense, it becomes your low-power device's power suppy, it just happens to have the added benefit of having a built-in backup battery. Coming from a Ham Radio perspective, some hams run their base stations off of deep-cycle marine batteries with some form of charger keeping them topped off. This way, the radio operator can operate his or her station for days just on emergency power. Since a lot of ham gear is designed to operate off of 12VDC (with some notable exceptions like your high-power amplifiers). It shouldn't be hard to develop a decent grade Low-power UPS for home or small office use that can run these low power devices for days at a time with out all the inefficiencies of converting VAC to VDC and back again. And there's probably a bunch of Raspi (or similar low-power computer boards) enthusiasts who already have for their own personal use. - Joseph Swick