Flywheel/Encoder patterns

[Jeffrey Engel]

> Subject:       Re: Flywheel/Encoder patterns
> From:          Kalle Pihlajasaari <kalle at device.data.co.za>

> Hi There,
> 
> > An encoder giving absolute crank position would implicitly supply an 
> > interrupt when the position changes value. Reading crank position directly 
> > means you wouldn't have to fool with timers or counters to derive it. You'd 
> > also know exactly what the position is upon start-up without having to store 
> > the last known position info upon shutdown. No way around the cam sensor tho 
> > that I can see.
> 
> I still have not figured out why one could not replace the distributor
> with a 512 line Grey/binary encoder with 9 bits of absolute crank position.
> 
> Make a backlash free coupling to the shaft and perhaps preload the
> shaft in the engine as well.
> 
> Absolute position to 1.4deg on the crank (0.7 on the cam shaft)
> 

Sarcasim?  Seriously, Bill "Grumpy" Jenkins makes the point in his 
book on Chevy race motors that the crank flexs enough that isolating 
the timing is important.  'Course he was talking about 650+ HP.

It seems to me that it would be easy to get so precise that the real 
world variations would confuse things badly.

je
jengel at fastlane.net