Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id B73B538000084; Mon, 8 Apr 2013 15:31:02 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1UPHCG-0000we-PP for rs_out_1@blacksheep.org; Mon, 08 Apr 2013 19:53:40 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1UPHCG-0000wV-5Z for rsgb_lf_group@blacksheep.org; Mon, 08 Apr 2013 19:53:40 +0100 Received: from nm3-vm7.bt.bullet.mail.ir2.yahoo.com ([212.82.99.226]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1UPHCD-0000fw-UY for rsgb_lf_group@blacksheep.org; Mon, 08 Apr 2013 19:53:39 +0100 Received: from [212.82.98.42] by nm3.bt.bullet.mail.ir2.yahoo.com with NNFMP; 08 Apr 2013 18:53:17 -0000 Received: from [217.146.189.127] by tm3.bt.bullet.mail.ir2.yahoo.com with NNFMP; 08 Apr 2013 18:53:17 -0000 Received: from [127.0.0.1] by smtp830.mail.ird.yahoo.com with NNFMP; 08 Apr 2013 18:53:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1365447197; bh=eKvdD6G8NQGgZoWgswGJgABZCGmb2okU7TJeJtnD2+4=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:X-Rocket-Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-Antivirus:X-Antivirus-Status; b=ygePi9T8xpkhLTxsZOUf+xjsMAq/lnRoVrqjJ2dZG1c59TJgxF3cEGFGYSUaX2TXZ/pcbgLuNXmx2Vs3ejn5ZXRe2yL6hDl6cxrFYP9O7Bp7Y5Gy/SvZykac4rVFQ/GegcMm6Av7TK0j3598phFttJjwRiJy67CB3fU2aaC7jC8= X-Yahoo-Newman-Id: 108412.23663.bm@smtp830.mail.ird.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: oNQULRUVM1niQcgXr8PFODdnjvBrAaFkjYTmyTy0521M70Z GlR3Yn3KHrUWbCNftklU.LsnAHMcYvLH6TaX7RJaskNSNiWQLIHqcpRnbdk5 pn3EEGTSSWCuIGABX5pUEPcbdGy48HPw7K3PpU6XSzFhHGB.BhSZmQ7mLpt4 X9Z3I8fIsZ210r.tQEV.STZjNaAmgmy8OyammduMvvwvswy1ILyYezA5S3uS 2AEHXrhxeP5FActak4_VK0CuTwMEwPV5pdYGK377YAu7r1HMe0Wxu7mzi2Pw 1OR4aaz7BKKxft2GUSenRmYfn8kxpY.amgSAPydbKSAkLkVJ8OmjLFfRQjfs Jglb91Do8jLGsc7NefFAYZ2HUePZget6p8mkQSMecYJbtG619jAJ3LxFYdfR Op8SPAt5K9nYDdJ7yI.OUJr8WmqPp.TPN02Q2wOr3XPI2AzqoUEhtzbNHSYi QKqhBCYVUjiA- X-Yahoo-SMTP: fpz.2VeswBBs59bVshRPmMN51lcO2lgFRIvE4XTqE8dRwOxd70E- X-Rocket-Received: from gnat (alan.melia@86.149.140.116 with login) by smtp830.mail.ird.yahoo.com with SMTP; 08 Apr 2013 11:53:16 -0700 PDT Message-ID: From: "Alan Melia" To: References: Date: Mon, 8 Apr 2013 19:52:47 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Antivirus: avast! (VPS 130408-1, 08/04/2013), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Ah interesting problem Warren.... why is it over-current?? if it is over-current because a high voltage has welded/melted a short between drain and source, then the protection wont help ....high currents usually lead to excess heating ......but what is the real cause? If you really need DC supply protection would not a high-side current monitor be easier/faster??? The problem then could be there is enough energy stored in the PA choke to zap the FET before, or even if, you can disconnect the supply. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.82.99.226 listed in list.dnswl.org] 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 0cdfd8d5ce44f1724c623c4ac9f44df6 Subject: LF: Re: Hall Effect for Over-current shutdown? Content-Type: multipart/alternative; boundary="----=_NextPart_000_00C1_01CE3492.A504D530" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.4 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_30_40, HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-mk04.r1000.mx.aol.com ; domain : btinternet.com DKIM : fail x-aol-sid: 3039ac1d618851631af412bd X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : temperror This is a multi-part message in MIME format. ------=_NextPart_000_00C1_01CE3492.A504D530 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ah interesting problem Warren.... why is it over-current?? if it is = over-current because a high voltage has welded/melted a short between = drain and source, then the protection wont help ....high currents = usually lead to excess heating ......but what is the real cause? If you = really need DC supply protection would not a high-side current monitor = be easier/faster??? The problem then could be there is enough energy = stored in the PA choke to zap the FET before, or even if, you can = disconnect the supply. OK drive fails permanently on might be a condition it would protect the = FETs against with DC coupled drive Alan G3NYK ----- Original Message -----=20 From: Warren Ziegler=20 To: rsgb_lf_group=20 Sent: Monday, April 08, 2013 7:15 PM Subject: LF: Hall Effect for Over-current shutdown? Anyone using a Hall effect device for overcurrent sensing and shutdown = in a MOSFET amplifer? --=20 73 Warren K2ORS WD2XGJ=20 WD2XSH/23 WE2XEB/2 WE2XGR/1 ------=_NextPart_000_00C1_01CE3492.A504D530 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ah interesting problem Warren.... why = is it=20 over-current?? if it is over-current because a high voltage has = welded/melted a=20 short between drain and source, then the protection wont help = ....high=20 currents usually lead to excess heating ......but what is the real = cause? If you=20 really need DC supply protection would not a high-side current monitor = be=20 easier/faster??? The problem then could be there is enough energy stored = in the=20 PA choke to zap the FET before, or even if, you can disconnect the=20 supply.
 
OK drive fails permanently on might be = a condition=20 it would protect the FETs against with DC coupled drive
 
Alan G3NYK
----- Original Message -----
From:=20 Warren = Ziegler=20
Sent: Monday, April 08, 2013 = 7:15=20 PM
Subject: LF: Hall Effect for = Over-current=20 shutdown?

Anyone using a Hall effect device for overcurrent = sensing and=20 shutdown in a MOSFET amplifer?

--
73 Warren K2ORS
        =  =20       WD2XGJ
          =  =20     WD2XSH/23
            =  =20   WE2XEB/2
              =  =20 WE2XGR/1

 
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