X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-curtail.atl.sa.earthlink.net ([209.86.89.64] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTP id 6614208 for lml@lancaironline.net; Mon, 25 Nov 2013 21:07:33 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.64; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=PV8NVNnG1lSDw43cEhts3A7Ch+fdDs2VY7yuADrytQ6c4pqpCyecLh7uNsgCyWHv; h=Received:From:Content-Type:Date:Subject:To:Message-Id:Mime-Version:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [70.105.253.253] (helo=[192.168.1.24]) by elasmtp-curtail.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1Vl83A-0003Os-Jz; Mon, 25 Nov 2013 21:06:53 -0500 From: Colyn Case Content-Type: multipart/alternative; boundary=Apple-Mail-179--897482691 Date: Mon, 25 Nov 2013 21:06:50 -0500 Subject: A couple Tyco papers on emf reduction in relays To: "lml@lancaironline.net List" Message-Id: <77E4292A-D067-4CF9-B085-01CB6C03F970@earthlink.net> Mime-Version: 1.0 (Apple Message framework v1085) X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da9401187bfd338929dbbdc75f68ba1333371350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 70.105.253.253 --Apple-Mail-179--897482691 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii I just stumbled across these while researching something else. Recently there have been some reference to how to protect switch = circuits connected to relays. Here are two papers done by Tyco which = have been corroborated by certain others and are consistent with Eric = Jones' recommended use of Snapjacks (bi-directional zener diodes). Some methods (not recommended here) of protecting the switch contact = result in extending the opening time of the relay, which causes arcing, = bouncing and degeneration of the relay contacts. (not a good thing for = maximizing starter current). If you are going to do something in this department, I highly recommend = reading these. (or just use EV100 relays and be done with it) http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf =20 http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3264.pdf Colyn --Apple-Mail-179--897482691 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii ht= tp://relays.tycoelectronics.com/appnotes/app_pdfs/13c3= 311.pdf

ht= tp://relays.tycoelectronics.com/appnotes/app_pdfs/13c3= 264.pdf

Colyn