That is my point. If you measure a single rotation of the drive shaft you have 1 rev. Now that Rev could have happened in any time frame. Until you have rev #2, you have no way to measure any time interval with or without a clock.

So lets say that you give a little to the engine after startin it. #1 might fire 3000 times, each of these fires being accounted for by the Tach wire hanging off of #1 cable. Without some time constant, how can you know that the 3000 fires happened in 1 min as apposed to 30 seconds?

I fully understand how to count firings, that is simple. I just want to understand how the second value of time is incorportated into an analog or gear driven type of device?

I have been trying to work out the mechanics/logic of this type of measure for a while now and finally decided I had to just ask. To me this is like trying to imagine infinity. Please help me with my mental stress.

Tom

Whats down in the well comes up in the bucket, so watch who's KoolAid you drink.