Return-Path: Received: from [199.185.220.240] (HELO priv-edtnes84.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.2.2) with ESMTP id 421046 for flyrotary@lancaironline.net; Sun, 19 Sep 2004 01:16:03 -0400 Received-SPF: none receiver=logan.com; client-ip=199.185.220.240; envelope-from=haywire@telus.net Received: from Endurance ([142.179.62.182]) by priv-edtnes84.telusplanet.net (InterMail vM.6.01.03.03 201-2131-111-105-20040624) with SMTP id <20040919051531.MVRI14781.priv-edtnes84.telusplanet.net@Endurance> for ; Sat, 18 Sep 2004 23:15:31 -0600 From: "Todd Bartrim" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Engine start Date: Sat, 18 Sep 2004 22:15:21 -0700 Message-ID: <001401c49e07$a9c1da30$0101a8c0@Endurance> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2742.200 You may have gotten a response on this already, but those mini-switches at the rat shack are rated 10A !AC!. That's a very different animal than 10A DC. In AC current, the electrons sort of bounce back and forth without really going anywhere. In DC, they have to actually flow, and this causes a lot more stress on junctions. -- http://www.ernest.isa-geek.org/ "Ignorance is mankinds normal state, alleviated by information and experience." Veeduber This is more or less correct, but the big difference is that AC is self quenching as every half cycle the voltage passes through 0volts anyways, but in DC the voltage is at a steady state. This is particularly important when the load is inductive such as found in the windings of a motor or in your case the coil in your injectors. The induction in these coils resists change in current flow, so when you open these switches the current will arc over the contacts as they break contact, creating very high temps (white hot) over very short time period (mSecs). However I suspect that in your installation since it is fairly new and unlikely that you would have cycled the switch more than several dozen times, it is more likely just a cheap switch! My favourite switches are from Cole Hersee http://www.colehersee.com/home1.asp Very high quality, reasonably priced, large selection of products for every conceivable automotive switching application and available from an auto parts store near you! Todd Bartrim RV9Endurance 13B Turbo Rotary C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm "The world will always have a place for those that bring hard work and determination to the things they do."