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Cessna Split Master/Bat switch-Can I use it?

Jeff Vaughan

Well Known Member
I will be installing a LASER ignition on one mag and magneto on the other. I had planned on using the Cessna split master/bat switch that I am use too. I read in Aeroelectric that this type switch can not be used with electronic ignitions. No explaination. Is this really the case ? Please any of you electronics types help me out here.

Jeff vaughan
 
Cessna Bat/Master switch

Are you are using it as a Battery/Master switch, or as part of the ignition?
It should be fine as a Bat/Master switch (after all that's what it is :rolleyes: ) If not, some sort of diagram or explanation is needed to explain where you plan to use the switches.

Dennis Glaeser
7A Wings
 
Jeff, it will work fine. The split switch is actually only for the electrical system (battery and alternator). The ignitions are usually, but not always, on separate switches. In your case, the LASAR will work with the standard keyed L & R ignition switch.

Vic
 
OOPS I ment standard ignition keyed switch

Sorry, I mistakenly wrote split switch and I ment the standard keyed type switch.

Jeff Vaughan
 
OK but LASAR on one side?

I have never heard of one LASAR/ Magneto combo, the LASAR usually comes in pairs. Do you mean Lightspeed?

I don't know about LASAR, never used one, but since they are certified for aircraft I assume they are designed for IGN key use. (Ign key=standard bendix type left, right, both and start switch, key operated)

I do know lightspeed has a IGNITION key option, but standard config does not allow use of a key switch.

Most electronic ignitions are controlled by a positive voltage. Magnetos work on a ground of the P-lead, so a standard Ign key switch designed for mags will not work. I think the LASAR works like a magneto? (call the company)

Bottom line: Why not have toggle switch for ignition. Are you worried about security? I am and have features to keep anyone from starting the aircraft (top secret). I do have IGN toggles for electronic ignition.

A key switch may slow a thief down, but its not going to stop them. Besides most crime is stealing avionics. However in Mexico or other places prop locks and other security should be considered.

Again I am confused about the single LASAR thing and would call Unison and ask if that's cool. I know they are always sold and used together. I can't think of a reason you can't do it, but I have zero experience with them. If you are talking about Lightspeed you may be in luck with the IGN key switch thing. Last if use "OTHER" electronic ignitions, than NO to the key switch. You could use a relay, but that would add a failure point to IGN power which I would not care for from a reliability standpoint. G
 
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