Return-Path: Received: from spdmbaaa.compuserve.com ([149.174.206.153]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Fri, 21 Jul 2000 12:05:54 -0400 Received: (from mailgate@localhost) by spdmbaaa.compuserve.com (8.9.3/8.9.3/SUN-1.9) id MAA06284 for lancair.list@olsusa.com; Fri, 21 Jul 2000 12:12:14 -0400 (EDT) Date: Fri, 21 Jul 2000 12:10:25 -0400 From: James Frantz Subject: Battery isolation and diodes Sender: James Frantz To: "INTERNET:lancair.list@olsusa.com" Message-ID: <200007211210_MC2-AD0C-EFFE@compuserve.com> X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Diodes most frequently fail in the shorted rather than the open condition. Some time ago in the Lanciar Network News, George Stevenson reported a primary battery explosion due to an alternator over voltage. His secondary battery kept the electronic ignitions going but due to the fried isolation diode the secibdary battery also tried to run everything else including the hydraulic pump. He did a fine job in recognizing the problem and took the appropriate steps which included a emergency gear extension and immediate landing. The secondary battery was probably minutes from being ehausted which would have resulted in an engine stoppage in addition to the cockpit smoke and many other problems George was dealing with. I like the idea of an essential bus that can be isolated from all the non essentials with a mechanical switch that closes/opens a relay. I will send Marve my three bus electrical system for inclusion in the LNN after Oshkosh. I too am a Bob N. student and like Bob's approach to aircraft electrical design. Jim Frantz >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>