Lightspeed tach output?
 

Hi all, Klaus is out of the office for a bit so I'm trying find this answer elsewhere.

We're finishing up a Lyc. TIO-540 engine which is on the dyno now. Using a LightSpeed plasma 3 system. Looking at the wiring schematic there should be a tach signal coming out of the input harnesses...our input harnesses only go to the position sensor and +12v/gnd. See picture below...



Is it standard to have to solder in the tach output wire? We have the displays as well, but our data acquisition will deal with an rpm pulse better than analog 0-0.3v. So splicing into the display's harness would be a last resort.

Thanks in advance,

Marshall

There are a couple of options for the tach signal - sounds like you want the one from the input connector. Yes, you have to solder in a wire for that. There is also a tach signal on the output connector but my recollection is that it's analog.

Bob

Yes you need to install a wire into pin 6 of the input connector to pick up the tach signal pulse.

Appreciate the quick response guys. 400hp here we come!

Regards,
Marshall

'Not sure what version of LSE you have, but the tach output on the latest PIII is on the input connector on 6 and 13, with 6 being the signal and 13 the return. The output comes from an opto-isolator which can be configured to give a positive pulse, a pull-down, or a pull-up depending on the avionics its connected to. No two devices want the same kind of tach input; too bad thay didn't standardize.

?????
 

What kinda airplane is getting this motor?

Best,

How can I reconfigure the output? I wired the leads out from each ign. box and so far am not seeing any signal...our data acquisition can accept rising or falling, neither worked though.

Thanks!

Marshall

This particular engine is for:


info @ www.carteraerospacedevelopment.com

Though we just sold another turbo system to an RV6 owner last week.

Marshall

'Just talked to Klaus, who's in Germany, and he said the boxes he sends out now are all configured to put out a +10V pulse. Two of the older EFIS required a different configuration, and as it says in the manual, send the units back to him and he will reconfigure them. If you bought your units directly from him and you tell him what your tach pulse is for it will be configured correctly and he will provide a shielded wire on 6-13. But if you ordered your units from someone else those wires are not on.

I found the problem...I had forgotten to disable the engine tach drive output, so the datalogger was getting competing signals...

Thanks again for the help.

Marshall