Tachometer transducers

[jimbower]

I have a Lycoming O-320 with one magneto and one Lightspeed electronic ignition module. Connecting the left RPM wire to the P-lead was easy, but I don't know where to connect the right RPM wire. I bought a Westach tachometer transducer, but I found it only outputs an AC voltage proportional to the engine's RPM. The Lightspeed ignition does have a square wave output. Would that work for the other RPM wire? I guess if worse comes to worst I can just get my RPM from the one magneto, but that seems like I'm depriving myself of something. Thanks.

Jim Bower
St. Louis
RV-6A super slow build

 

[dynonsupport]

The square wave on the Lightspeed input connector is 10V to ground, which is good, but it's reaaaaly short, which puts it up against the limits of hardware detectability for our EMS products. Some people have reported it works just fine, while others report that it's either intermittent or doesn't work too well. Your mileage may vary.

 

[jimbower]

Thanks for the fast reply! I'll go ahead and connect to that 10v square wave and see what happens.

 

[PhantomPholly]

Thanks for the fast reply!  I'll go ahead and connect to that 10v square wave and see what happens.  

Also note that some LightSpeed units (you will need to provide Klaus with your model and serial number to find out) only put out 5v, not 10v as advertised. How do I know this?



Klaus will "upgrade" the unit for you (I believe at no charge, but he may have only meant that for me) to output 10v if you return it to him.