From owner-freebsd-chat@freebsd.org Sun Nov 22 00:30:28 2020 Return-Path: Delivered-To: freebsd-chat@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id AABEA474A05 for ; Sun, 22 Nov 2020 00:30:28 +0000 (UTC) (envelope-from brett@lariat.org) Received: from mail.lariat.net (mail.lariat.net [66.62.230.51]) by mx1.freebsd.org (Postfix) with ESMTP id 4Cdrm35bTjz3pN4 for ; Sun, 22 Nov 2020 00:30:27 +0000 (UTC) (envelope-from brett@lariat.org) Received: from Toshi.lariat.org (IDENT:ppp1000.lariat.net@localhost [127.0.0.1]) by mail.lariat.net (8.9.3/8.9.3) with ESMTP id RAA29768; Sat, 21 Nov 2020 17:30:16 -0700 (MST) Message-Id: <202011220030.RAA29768@mail.lariat.net> X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Sat, 21 Nov 2020 17:30:08 -0700 To: Ralf Mardorf , freebsd-chat@freebsd.org From: Brett Glass Subject: Re: Sustainability of switching power supplies In-Reply-To: <20201121092444.2355c5a7@utnubu> References: <20201121092444.2355c5a7@utnubu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Rspamd-Queue-Id: 4Cdrm35bTjz3pN4 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of brett@lariat.org designates 66.62.230.51 as permitted sender) smtp.mailfrom=brett@lariat.org X-Spamd-Result: default: False [-2.70 / 15.00]; ARC_NA(0.00)[]; RBL_DBL_DONT_QUERY_IPS(0.00)[66.62.230.51:from]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+a]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[lariat.org]; NEURAL_HAM_LONG(-1.00)[-1.000]; SPAMHAUS_ZRD(0.00)[66.62.230.51:from:127.0.2.255]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-1.00)[-0.997]; RCPT_COUNT_TWO(0.00)[2]; FREEMAIL_TO(0.00)[zoho.com,freebsd.org]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:19092, ipnet:66.62.228.0/22, country:US]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[freebsd-chat] X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Nov 2020 00:30:28 -0000 At 01:24 AM 11/21/2020, Ralf Mardorf via freebsd-chat wrote: >My experiences with modern computer power supplies aren't bad, but >my impression about switching power supplies in almost everything and >the sustainability of this approach ... voltage undersized caps etc. >isn't good. Not sure what you mean by "sustainability" here. If you mean their environmental impact, well, it depends. If properly designed, switchers are more efficient than linear supplies, generate less heat, and waste less energy. However, because they're more complex and contain more toxic metals and more solder, they have the potential to generate more harmful waste when they're retired. If you mean reliability, they're actually pretty close. Switchers are more resistant to power surges (because they can withstand higher input voltages with no damage) but suffer due to their complexity; there are more parts to fail. And the part that fails most often in power supplies - the electrolytic capacitor - is present in both types. (The "capacitor plague" of the last decade is still haunting us today, because even now millions of power supplies made with the faulty capacitors are still in use and/or still in supply chains. But even good electrolytics are essentially quick-charging batteries and do fail more often than other components.) That's why Glass's Law of Electronic Diagnosis states: Whenever you are asked about the failure of an electronic device, simply say, "It's the power suppply." You will be correct about 99% of the time, and since you came up with the right answer before you even looked, you'll be considered to be either psychic or a bloody genius. ;-) --Brett Glass