Return-Path: Received: from pop3.olsusa.com ([63.150.212.2] verified) by logan.com (CommuniGate Pro SMTP 3.5.2) with ESMTP id 1034000 for rob@logan.com; Thu, 31 Jan 2002 09:05:39 -0500 Received: from siaag1ad.compuserve.com ([149.174.40.6]) by pop3.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-71866U8000L800S0V35) with ESMTP id com for ; Thu, 31 Jan 2002 09:02:39 -0500 Received: (from mailgate@localhost) by siaag1ad.compuserve.com (8.9.3/8.9.3/SUN-1.12) id JAA24819 for lancair.list@olsusa.com; Thu, 31 Jan 2002 09:04:34 -0500 (EST) Date: Thu, 31 Jan 2002 09:04:22 -0500 From: James Frantz Subject: Electronic ignition Sender: James Frantz To: "INTERNET:lancair.list@olsusa.com" Message-ID: <200201310904_MC3-F011-F975@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> >how much time is left when the alternator fails.< Some time ago in the Lancair Network News we reported about a friend of mine that had dual electronic ignition in his 320. One side was run from the main power distribution system and the other from a small battery isolated by a diode form the aircraft's main distribution system. His main battery blew up due to an overvoltage. The isolation diode shorted out putting the = isolation battery in the position of trying to = run not only the electronic ignition but also the entire aircraft electrical load. The overvoltage forced a lot of = electrical systems like his HSI and engine = instruments to fail and the little battery was able to get the aircraft back on the ground without an engine failure but just barely. Isolated dual electronic systems are OK. However, if you plan to charge both batteries from the same alternator, be careful in how you design the isolation. = In the above case the isolation diode was = designed to handle 30 volts but this was not = enough when the 14V alternator ran away. Another problem with isolation diodes is that they ususally fail in the shorted mode. My next project will be to put one electronic ignition on my 360 avoiding the isolation = issue altogether. = Jim Frantz >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>