Smitty:

I wont try to give you a flowchart, but here’s what I’m working on.

Inputs to the system are throttle and rudder signals from the rx, and an rpm signal from each engine.

Output is separate signals to the throttle servos.

If it does not get both rpm signals it passes the receiver throttle signal through to the throttle servos with no alteration.

Both rpm signals are sent to counters, the difference is divided by two, added to the pulse time for the slower and subtracted from the faster, with the rx throttle pulse time being the center.

>This eliminates the “Master/Slave” of the EMS system, and therefore prevents the slave engine starting at full throttle, and takes care of any worries about “Stronger” and “Weaker” engines – self correcting.<

>At this point we have the ideal synchronizer for straight flying, but since we want a little fancy, we add the differential command.<

Check rudder pulse time. If greater than 1.30ms and less than 1.70ms, OR if rx throttle pulse time greater than 1.5ms ignore rudder signal.

Check rudder pulse time. If less than 1.30ms or greater than 1.70ms, AND if rx throttle pulse time less than 1.5ms add (throttle time – 1ms)/2 to opposite throttle pulse time.

>This gives differential throttle for taxi realism, and extreme maneuvers in flight, while ignoring normal rudder movement, and still keeping the engines in tune otherwise. Also, if the engines are at 50% power or greater the rudder has no effect. And by basing the added pulse time on the throttle signal we can vary the amount of engine acceleration.<

I can make this work on my P-3 computer, but I haven’t managed to get it inside a small plane. And it’s my ideal sync system.

Hope this helps you.

Twin engines in sync,
. That's best, I think.

Bill,