Thank Mark for the reply. Give me something to think about.? Did the switch fail because it was undersized for a DC circuit? ?
Sent on the new Sprint Network from my Samsung Galaxy S?4. <div>-------- Original message --------</div><div>From: Mark Langford via KRnet <krnet at list.krnet.org> </div><div>Date:10/08/2014 8:02 PM (GMT-06:00) </div><div>To: KRnet <krnet at list.krnet.org> </div><div>Subject: Re: KR> Ignition switch </div><div> </div>Paul Visk wrote: >> I was looking at WW's Critical Electrical System Diagram and thought of you when your ignition switch failed. Did both sides fail or just your primary side? WW has a DPDT switch fuel/coil on his design. I'm thinking this is a single point failure possibility. Wouldn't it be better to have two separate SPST switches to totally isolate the systems?<< Only one side failed...the beauty of a double pole switch...the two circuits are completely isolated from each other, except they are within one enclosure. I'm pretty sure WW got that idea from me...I did it first and he liked the idea, at least that's what he told me. You could use two SPST switches, but when you do that you have the possibility of having them both turned off at once...not good in a rapid-first highly tense situation where that could be overlooked, and you'd also be connecting fuel to ignition, rather than keeping them separated. You'd need four SPST switches to accomplish the same functionality, with an increase in human error potential. When I flip my switch I wouldn't even notice anything happened except the green LED turns RED (it's a bicolor). See http://www.n56ml.com/electrical/index.html to get the gist of how mine is done (although the bicolor LED isn't shown here). N56ML flew 1130 hours with this setup without a single hiccup. Since the bad switch incident, I now start the engine with the switch in the "backup" mode, so the ignition gets its juice from the backup battery, rather than the main circuit. This not only gives me a check of the backup battery, but it ensures the ignition system is getting a full 12.8V during starting, rather than "whatever is left over" when the starter has taken a huge bite out of the main battery power. Once it starts, I swap it over to "primary" to make that red LED go away, and continue to fly it that way until I land. Works for me! Of course the iEFIS also monitors and displays the voltage on both backup and main battery at all times anyway, so the main point is more juice to the ignition system and a check of the switch, rather than doing it on runup. -- Mark Langford ML at N56ML.com http://www.n56ml.com _______________________________________________ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
