bluejets

John,
I changed the curve by changing values in the table between 1600 rpm and 7500 rpm. With the values I put in, this resulted in the curve changing to a dead straight line between the 2 points. If it works i.e. changes the delays like I think it should, I give you a rundown on how to do it.
Doesn't work by trying to drag the curve as far as I am aware.
Transistor, I did not use 2N4401, I think maybe BC547 so that might be why I showed it a-about. I thought I checked that..mmm.ok
Either way, I did have it connected the right way but i will change it to show your transistor.
Ok..cheers...Jeff