keyswitch with lightspeed+mag

[prkaye]

I'm using a L/R/Both/Start keyed ignition switch from spruce. I have a mag on the left side, and a Lightspeed Electronic Ignition on the right side. Does anybody have a schematic for wiring the keyed switch for this configuration?
I have the installation diagram from spruce http://www.aircraftspruce.com/catalo...NSTALL-DIA.jpg, but am just wondering how to modify this to account for my Lightspeed on the left side instead of a mag.

[rvmills]

Phil,

I looked at LSE's website and in the FAQ section it says this:

"...all Plasma II Plus and Plasma III CDI systems can be operated with a standard aircraft key switch. A "P"-Lead (wired to the output connector) is provided and should be connected to the key switch in the same way as the magneto "P"-Lead. There is no current drain on your battery when power is supplied via the input connector and the key switch is in the off position. A pull-able circuit breaker should still be installed in the positive power wire.

The older Plasma II does not have this feature and must be turned on and off with a quality toggle switch."

There is an install manual section here:

http://www.lightspeedengineering.com...II_II+_III.htm

Section 2.8.A bullet 4 talks a little about key switches, and refers you to the input connector diagram (link to that in Section 2.9).

Not sure if that is what you need...I got a little lost looking at it, but I'm running toggles. Maybe someone actually using a key switch can press the "easy button" and have a simple explanation.

Hope this helps in the meantime!

Cheers,
Bob

[prkaye]

Cool thanks!
The ACS daigram shows two leads with the comment "Jumper used when left mag is Retard Breaker mag or has impulse coupling". I'm not sure what this means? How do I know whether to use the jumper?

[DennisRhodes]

Some Lyc use only one mag with a Impulse coupling. My experience is with Slick mags. The second Mag usually has no impulse . The impulse is the mechanical spring CLICK you hear when you rotate the prop slow. The implulse coupling actually delays the spark so that you can crank the engine. With a impulse coupled mag only on one side you need to Ground the other mag while you initiate the start and engage the starter. Generally the right mag is grounded allowing the left impulse mag to be active during the cranking. The jumper on the back of the switch actually does this for you , Check it with a Ohm meter. If you have only one impulse coupled mag you should ground the other while cranking. I have a Plasma II + and it does allow you to wire in a P lead type ground to that Electronic pack. It work excellent when wired just like the instructions. The EI cranks the engine Excellent regardless of the other mag Impules or NO Impule coupled mag. Forget the jumper if using EI Plasma./ DRR

[scsmith]

Is pretty similar. I have a Plasma II+ on the left, and a standard slick mag on the right (w/o impulse coupling)

I have the standard key switch, and I left the jumper in place to ground the right mag while starting, so it starts ONLY on the Plasma II+.

The Lightspeed retards the spark timing to TDC for starting, and gives a good strong spark. If the right mag fires at 25 BTC while trying to start, there is a chance it will make a kick-back.

The lightspeed looses its ability to retard the spark at some very low voltage ( I forget the value, something like 5 v) but if it does, then there is risk that the lightspeed could cause a kickback, but this is very unlikely as long as you keep your battery charged.

[prkaye]

So it sounds like in any case it can't hurt to put the jumper in?