Tach signal from Lightspeed

jacktunnell

I love flying!
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Jan 19, 2013
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41
Question 1. Does anyone know if the tach signal coming out of a lightspeed 3 is active if the unit is turned off or failed?

Thanks, Jack
 

jacktunnell

I love flying!
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Jan 19, 2013
Messages
41
Understood TRCsmith but I'm asking about the pulsed tack output on Pin 6 of the Input Connector. I think that may come from the sensor by the magnets.

I have a message into Klaus on this but thought someone might know for sure.

If no, I will have to take the tach output from each of the dual systems to a tach signal selector, and then to the EMS.

That does not seem very elegant as a solution.
 

jacktunnell

I love flying!
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Jan 19, 2013
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41
Just got a reply from Klaus and TRCsmith was 100% Correct. That is unfortunate.

Is it confirmed that only one tach input is available on the EMS? Either High or Low power pulses.

It would be much more elegant to have two tach readings than to have a selector switch.

The selector will have to be used when checking ignition system operation with one Lightspeed turned off.
 

amolny

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May 3, 2012
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Jack - A couple of assumptions: you are using the EMS-220 engine module, and you don't want the RPM to read zero when you switch off one ignition during your runup. The EMS-220 engine monitor has left and right RPM inputs. I used the low voltage inputs for my dual Lightspeed installation. The Skyview is smart enough to use whichever signal is active, so the RPM displays just fine when I do my "mag" drops.
-Adam Molny
 

dynonsupport

Dynon Technical Support
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Mar 23, 2005
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13,226
Yeah, as was said, every EMS Dynon has ever made has two RPM inputs and will automatically switch. The EMS-220 has high/low voltage inputs as well, so if you look, the EMS-220 has two high inputs and two low inputs.

Your lightspeed works just like a normal mag, which is the whole reason we have two inputs.
 

flyingboy

Member
Joined
Jan 11, 2010
Messages
95
Location
Australia
Hi Jack, FWIW I have two Plazma lightspeed systems (no Mags) and connected it as per Klause specifications via two seperate switches, seperate starter, and Followed the Dynon manual, re low voltage connection. I have not had any issues and have the normal RPM varaiation from either switch. (Mag Check) Everything is working perfectly so far so good. I have two Odysey Batteries and run one plazma of each Battery just as a back up. Cheers Hugh
 
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