From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x232.google.com (mail-qt0-x232.google.com [IPv6:2607:f8b0:400d:c0d::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 629F03B29E for ; Tue, 6 Jun 2017 14:40:11 -0400 (EDT) Received: by mail-qt0-x232.google.com with SMTP id u12so117233870qth.0 for ; Tue, 06 Jun 2017 11:40:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=khFUQXZaF+rKVWGVZmKxK/dkX4nvddnS6NGb3teQLKc=; b=Gpy2+Ru+LWgxOqobX/1dKZJm+/hMiUiyoiWubbaWSNWtoCTUFYVPP/lgzqQ6E9uSKF tsgokrfkK8W7LNxwFr4FyrImno6gH+Op/WyzGkMN8ZuSw3KhwWK1qnhDm4S98Go+Cl54 IAs3Brrx0Tss3Em01sMNFO9lPC4a+WF7XHu4qjLpEdmHmjiUjf88Ycs9nUL8dZo4oW8x 6T2+EnsH03izLJthGZQFzQmiGNHGVajZbQ0uIlSmaAKimdPmGqpJubVqVMUYsXZpUq7i RbVLfbd48L9aNOReDsgepsnoth/a+c+CK6K0z5M+tqa82nJ5HD+uqOBO+qwLILdJiLUE pd+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=khFUQXZaF+rKVWGVZmKxK/dkX4nvddnS6NGb3teQLKc=; b=ghh6iN83ff2s+DkQUpMjfpvdWbqjPShLkl/znHU+TS9RsUh9JHkMFOuVEnqZKHL+zO a4kKC+KXa8qQ42FDAkwc7Ouxm6pGMFCLbLSx6mE792eN+GqQD4JHW68yQMiDq5zjWFnD k4SJI8ELhYexsSQ3C5eoYvsHiLn0i4eNP98dFJBjYR3v4Pok03PcPQeehoEQwGgdIOmh hJ5841GsnvNzpiIrKecIDRpLmYAul9ltecIRIEmUrb638nbLopW6XUlNOkFNn3txCnzK SxMe6o4jD4TdT7kZpuxA7KOKJ9Jt09jNkA2h01leCwt4NzfxCxFBOq59AyYnz310nkej NMfw== X-Gm-Message-State: AKS2vOzdQCM28vy+oxwcD461wJlGTo0/lCFB0Cn0n/6DE7pChgg25hqh uF4DlEH9hXsRuRF0 X-Received: by 10.55.76.140 with SMTP id z134mr31505343qka.35.1496774410581; Tue, 06 Jun 2017 11:40:10 -0700 (PDT) Received: from [10.100.1.55] ([144.121.2.62]) by smtp.googlemail.com with ESMTPSA id r125sm9750751qke.65.2017.06.06.11.40.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Jun 2017 11:40:10 -0700 (PDT) From: Richard Smith To: David Lang Cc: Dave Taht , "cerowrt-devel@lists.bufferbloat.net" References: <2d60e776-2a4f-de66-0d2f-a36568562f96@gmail.com> <10e962eb-7744-8041-7f61-b21ce8dad21d@gmail.com> Message-ID: Date: Tue, 6 Jun 2017 14:40:06 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <10e962eb-7744-8041-7f61-b21ce8dad21d@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Cerowrt-devel] solar wifi ap designs? X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 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: Tue, 06 Jun 2017 18:40:11 -0000 On 06/06/2017 08:04 AM, Richard Smith wrote: > On 06/05/2017 04:20 PM, David Lang wrote: >> On Mon, 5 Jun 2017, Richard Smith wrote: >> >>> My WNDR 3700v2 power supply is rated at 12V 2.5A which is a peak of 30W. >> >> don't forget that this includes providing power out to the USB port as >> well. >> >> yet another reason to measure things :-) > > > Ah. Yeah good point. Thats .5A. > I wired up my WNDR3700v2 running a fairly newish version of LEDE to my power supply. Idle with 5G and 2.4G active, upstream link (GibE) connected and 1 sta attached to 5G: 5.2 - 5.3 W. Running some upload/download tests: 5.2 - 8 W. On boot however there are brief spikes that required the current limit of my supply to be set up in the 1A zone. Given the info I saw in the buck regulators datasheet I suspected that the only reason it needs 12V is to run the +5V USB supply. 12V wall warts are super cheap so 12V is a reasonable choice from a BOM cost perspective. If that is true you don't care about USB then it should run fine at 5V Vin, and indeed it runs just fine at 5V Vin. I needed to up the current limit above 1A to allow it to boot. I set it to 2A and didn't try to find the exact spike threshold. 5V gives you a slight savings. Idle at 4.8W. That's about what I would expect. It's pretty easy to get close to 90% on a DC-DC converter these days without too much extra effort. -- Richard A. Smith