Received: from PCH.mit.edu (18.7.21.50) by mail.efplus.com (192.168.0.8) with Microsoft SMTP Server (TLS) id 8.3.485.1; Mon, 12 Jul 2021 14:05:43 -0700 Received: from PCH.MIT.EDU (localhost.localdomain [127.0.0.1]) by PCH.mit.edu (8.14.7/8.12.8) with ESMTP id 16CKuWWv025394; Mon, 12 Jul 2021 16:57:09 -0400 Received: from outgoing-exchange-5.mit.edu (OUTGOING-EXCHANGE-5.MIT.EDU [18.9.28.59]) by PCH.mit.edu (8.14.7/8.12.8) with ESMTP id 16CKuUnK025391 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 12 Jul 2021 16:56:30 -0400 Received: from w92exedge3.exchange.mit.edu (W92EXEDGE3.EXCHANGE.MIT.EDU [18.7.73.15]) by outgoing-exchange-5.mit.edu (8.14.7/8.12.4) with ESMTP id 16CKuD0m017720 for ; Mon, 12 Jul 2021 16:56:30 -0400 Received: from w92expo17.exchange.mit.edu (18.7.74.71) by w92exedge3.exchange.mit.edu (18.7.73.15) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Mon, 12 Jul 2021 16:55:56 -0400 Received: from oc11exhyb6.exchange.mit.edu (18.9.1.111) by w92expo17.exchange.mit.edu (18.7.74.71) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 12 Jul 2021 16:56:21 -0400 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (104.47.70.101) by oc11exhyb6.exchange.mit.edu (18.9.1.111) with Microsoft SMTP Server (TLS) id 15.0.1497.18 via Frontend Transport; Mon, 12 Jul 2021 16:56:21 -0400 Received: from DM5PR18CA0054.namprd18.prod.outlook.com (2603:10b6:3:22::16) by SN6PR01MB5135.prod.exchangelabs.com (2603:10b6:805:c5::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.25; Mon, 12 Jul 2021 20:56:20 +0000 Received: from DM6NAM11FT027.eop-nam11.prod.protection.outlook.com (2603:10b6:3:22:cafe::94) by DM5PR18CA0054.outlook.office365.com (2603:10b6:3:22::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.20 via Frontend Transport; Mon, 12 Jul 2021 20:56:19 +0000 Received: from mail-qt1-f174.google.com (209.85.160.174) by DM6NAM11FT027.mail.protection.outlook.com (10.13.172.205) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4308.20 via Frontend Transport; Mon, 12 Jul 2021 20:56:19 +0000 Received: by mail-qt1-f174.google.com with SMTP id d1so14999367qto.4 for ; Mon, 12 Jul 2021 13:56:19 -0700 (PDT) From: Denny Esterline To: Microcontroller discussion list - Public. Sender: "piclist-bounces@mit.edu" Date: Mon, 12 Jul 2021 13:56:07 -0700 Subject: Re: [EE] Redundant PSU for critical NAS server Thread-Topic: [EE] Redundant PSU for critical NAS server Thread-Index: Add3Ya3Rq6g6ljMnQ4SOWlVaZkGaKQ== Message-ID: References: <2fd4df00967f3c7f872cc7c87c6cc133.squirrel@mai.hallikainen.org> <20210712200859.60c4f038@raspberry> <0e7cd82f0e56339f242905e526fb401f.squirrel@mai.hallikainen.org> List-Help: List-Subscribe: , List-Unsubscribe: , In-Reply-To: <0e7cd82f0e56339f242905e526fb401f.squirrel@mai.hallikainen.org> Reply-To: Microcontroller discussion list - Public. Accept-Language: en-US X-MS-Exchange-Organization-AuthAs: Anonymous X-MS-Exchange-Organization-AuthSource: TS500.efplus4.local X-MS-Has-Attach: X-Auto-Response-Suppress: All X-MS-Exchange-Organization-SenderIdResult: Pass X-MS-Exchange-Organization-PRD: mit.edu X-MS-TNEF-Correlator: received-spf: Pass (protection.outlook.com: domain of gmail.com designates 209.85.160.174 as permitted sender) receiver=protection.outlook.com; client-ip=209.85.160.174; helo=mail-qt1-f174.google.com; dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=cGsSHtVSXWe4/mrx/7QBFNuzFzcstLiJQXXqHD2IaHk=; b=E0IShFeA1uFnDgsGWOfeIy5u5U5aYoBUFjq9zli/A+77bMaqcFFyLpa36vR0/a0rk4 ULLzR1qo1DQGOI2XQm5foTsT7NEBSmw4FFKW1rlLj0o4zN6RjedMy59zDm2irJmQRAVs L/aW408miLaQWGNusoxMOnbqOxWls6zSHysbGXmvcEN1X1K4U48UAD0/bsbr+hgxaGuf IWsxgknoNkDwXQZRZr4ZdgrHPDo8YowRnpRbTot0Mzwe2paZEmzpvffZ5cB6U7MwJRCt BdZHxS1Jzc2RmEyL0Tts3PWIBn84EQsntp1h23ihq1upa8nw/E9ZnnsR8to+EBr416tz vJCQ== authentication-results: spf=pass (sender IP is 209.85.160.174) smtp.mailfrom=gmail.com; mit.edu; dkim=pass (signature was verified) header.d=gmail.com; mit.edu; dmarc=pass action=none header.from=gmail.com; errors-to: piclist-bounces@mit.edu list-id: "Microcontroller discussion list - Public." list-post: x-beenthere: piclist@mit.edu x-mailman-version: 2.1.6 x-received: by 2002:a05:622a:409:: with SMTP id n9mr734915qtx.261.1626123378876; Mon, 12 Jul 2021 13:56:18 -0700 (PDT) x-topics: [EE] x-content-filtered-by: Mailman/MimeDel 2.1.6 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Don't consider myself the expert here, but I think the answer is a firm "Probably, most of the time, except when it's not." I suspect the better question is "why bother?" Diodes are cheap, risk is not. -Denny On Mon, Jul 12, 2021 at 1:37 PM Harold Hallikainen < harold@mai.hallikainen.org> wrote: > > > I've worked on a couple circuits that had multiple supplies. > > The term I heard used was "auctioneering diodes". > > A quick google gives ~10k hits and at least the first page seems releva= nt > > to the discussion. > > > > -Denny > > Could the output diode in a typical flyback switcher serve as the > "auctioneering diode?" > > Harold > > > > -- > FCC Rules Updated Daily at http://www.hallikainen.com > Not sent from an iPhone. > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .