Return-Path: Received: from wind.imbris.com ([216.18.130.7]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Sun, 10 Sep 2000 11:47:32 -0400 Received: from regandesigns.com (nortel131-172.imbris.com [216.18.131.172]) by wind.imbris.com (8.9.3/8.9.3) with ESMTP id IAA47239 for ; Sun, 10 Sep 2000 08:53:33 -0700 (PDT) Message-ID: <39BB9271.7C62FD99@regandesigns.com> Date: Sun, 10 Sep 2000 08:53:53 -0500 From: Brent Regan To: Lancair List Subject: RE: 12V vs/ 24V X-Mailing-List: lancair.list@olsusa.com Reply-To: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> A few other facts / comments to help with the decision: Hot starts. My 28 volt starter cranks my high compression 540 noticeably faster than than a 14 volt, low compression 550. As a result I have never had a hot start problem (dead battery). Conversion. If you must install 14 volt hardware, Vicore (www.vicr.com) makes an inexpensive (~$120) industrial DC-DC converter (VI series) that will produce 12 from 28 volts at 5 amps. It weighs 0.18 lbs and measures 2.25" x 2.25" x 0.52". Noise. Electrical noise can be lower in 28 volt systems due to lower currents. Amps make magnetic interference, not volts. I say "can" because noise is highly dependent on installation details. Existence proof. Virtually all cabin class aircraft are 28 volt. Why? I'll bet there is a good reason(s). Availability. If you are planning an all electric airplane, you may want to check into the availability of electric gyros. As I recall, 28 volt gyros were significantly cheaper than 14 volt. The only 14 volt system on my airplane is the Mac trim and it needs a converter regardless, if you want variable trim speed. Doesn't matter. It has been said that decisions that are difficult to make don't really matter. That is to say that if two choices are comparable, either will work just fine. IMHO 28 volt is the better choice. If you do chose 14 volts, however, then you won't be too far wrong ;) Regards Brent Regan >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>