From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yx0-f171.google.com (mail-yx0-f171.google.com [209.85.213.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 58E1E201AF7 for ; Wed, 9 May 2012 10:12:28 -0700 (PDT) Received: by yenq11 with SMTP id q11so979351yen.16 for ; Wed, 09 May 2012 10:12:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type; bh=Qh9855Hhz7cFqUL4RYlnOQk2wmd+v/N4c27+4YXrimw=; b=jfl2im/sRexPffOOgTOlP+TmaD3diaNLv2vkYbt1NJzZhip5gNXqFdk4VkIuYdEh+D l4EM290KyJnt0nPZlXAJDnbNz5h7pQkMGhTX9xzfTqPqL/fFD9UbYfiAHyuozQrO+d22 87ZXzc8PBLxVozohH99V5bmpMB/77QeEkj1e5E7MwlOeFwd091wZ3IBOlWkO1mduUuh0 k5b5gZniC2K0EACXkdN11WbkQDLQtU8nD9kg9WASdP8IMQj6PRyqmyO1HI4+m/vc6fhj JEFDOVlgoAEyQhABDduRTC1JK+vqKZDyEE2Wn+p88MV460Gv4bqkcw/jpOqk+X4BiHUP nLDw== Received: by 10.60.20.38 with SMTP id k6mr1331101oee.26.1336583546812; Wed, 09 May 2012 10:12:26 -0700 (PDT) MIME-Version: 1.0 Sender: tz2026@gmail.com Received: by 10.182.113.40 with HTTP; Wed, 9 May 2012 10:12:06 -0700 (PDT) In-Reply-To: References: <02af01cd2daf$05b24bb0$1116e310$@navisys.com.tw> <20120509164726.GA2102@thyrsus.com> From: tz Date: Wed, 9 May 2012 13:12:06 -0400 X-Google-Sender-Auth: EZFJ_mZ75aWe4fr3JCf70hztjWU Message-ID: To: Dave Taht Content-Type: multipart/alternative; boundary=e89a8fb2065e8539a404bf9d9bf8 Cc: thumbgps-devel@lists.bufferbloat.net, veronica , tcf@navisys.com.tw, Jau-Yang Chen , gloria@navisys.com.tw, lily Subject: Re: [Thumbgps-devel] Article -- Macx-1: GPS receiver with standard USB connector and PPS support X-BeenThere: thumbgps-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 May 2012 17:12:29 -0000 --e89a8fb2065e8539a404bf9d9bf8 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable For a given size (and circuit board footprint) a supercap will have much less capacity and it has an exponential voltage decay curve, so it might have plenty of charge but not at a voltage that will hold the data. This usually means hours, not days of backup. A good rechargeable lithium will last several years, maybe longer as there will be no charge/discharge, maintains voltage until it is nearly exhausted, and can hold the data for days or weeks. On Wed, May 9, 2012 at 12:55 PM, Dave Taht wrote: > On Wed, May 9, 2012 at 9:47 AM, Eric S. Raymond wrote: > > Dave Taht : > >> What would be the change in cost and delay in manufacturing to switch = to > >> using a supercap, rather than battery? > > > > Why would a supercap be better? > > Effective lifetime of... forever. no need for replacement. insanely > fast recharge. smaller (probably). What's not to like? > > I am not in a huge hurry to get into manufacturing, and I merely > wanted to cost out what what it would do to the bom, any changes to > the PCB, and get an estimate for the time it would take to do. I think > it will bump the unit cost up slightly, > but what price, forever? > > > -- > > Eric S. Raymond > > > > -- > Dave T=E4ht > SKYPE: davetaht > US Tel: 1-239-829-5608 > http://www.bufferbloat.net > _______________________________________________ > Thumbgps-devel mailing list > Thumbgps-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/thumbgps-devel > --e89a8fb2065e8539a404bf9d9bf8 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable For a given size (and circuit board footprint) a supercap will have much le= ss capacity and it has an exponential voltage decay curve, so it might have= plenty of charge but not at a voltage that will hold the data.=A0 This usu= ally means hours, not days of backup.

A good rechargeable lithium will last several years, maybe longer as th= ere will be no charge/discharge, maintains voltage until it is nearly exhau= sted, and can hold the data for days or weeks.

On Wed, May 9, 2012 at 12:55 PM, Dave Taht <dave.taht@gmail.com><= /span> wrote:
On Wed, May 9, 2012 at 9:47 AM, Eric S. Raymond <esr@thyrsus.com> wrote:
> Dave Taht <dave.taht@gmail.c= om>:
>> What would be the change in cost and delay in manufacturing to swi= tch to
>> using a supercap, rather than battery?
>
> Why would a supercap be better?

Effective lifetime of... forever. no need for replacement. insanely fast recharge. smaller (probably). What's not to like?

I am not in a huge hurry to get into manufacturing, and I merely
wanted to cost out what what it would do to the bom, any changes to
the PCB, and get an estimate for the time it would take to do. I think
it will bump the unit cost up slightly,
but what price, forever?

> --
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0<a href=3D"http://www.catb.org/~esr/"&g= t;Eric S. Raymond</a>



--
Dave T=E4ht
SKYPE: davetaht
US Tel: 1-239-829-560= 8
http://www.bufferb= loat.net
_____________________________= __________________
Thumbgps-devel mailing list
Thumbgps-devel@list= s.bufferbloat.net
https://lists.bufferbloat.net/listinfo/thumbgps-devel

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