Flywheel/Encoder patterns

[Mazda Ebrahimi]

Jonathan Barnes wrote:
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> 
> 
> >From: Mazda Ebrahimi <kleenair at ix.netcom.com>
> >Date: Sat, 21 Dec 1996 05:49:17 -0500
> >Subject: Re: Flywheel/Encoder patterns
> >
> >I think we determined that the most
> >accurate spark system would be driven by the crankshaft pick-up sensor,
> >with a TDC#1 reference from the camshaft sensor.  In the interest of
> >reducing sensor count,
> 
> >I think by going to a waste spark system and gang fire injector firing
> >during the first few engine rotations, we can compare the ionization
> >currents between the two sparks for each cycle of each cylinder and
> >determine which one represents the top of the compression stroke.
> 
> You seem to be trying to *reduce* ? your sensor count by substituting two
> ionization sensors and some trick comparison curcitry for a simple
> magnetic sensor. This dose not make sense to me can you please explain the
> system.

I think someone already makes a single chip ignition coil driver chip with a feedback 
signal to the processor, so the electronic component count is no higher than before 
(maybe a little more expensive).  Also, generally speaking, in production, one would 
almost always rather eliminate a sensor without sacrificing performance by just writing 
more software code.  You pay for code development once, but you pay for the sensor for 
every engine.  I'll try to look for the paper I read regarding the ignition driver 
circuit and post it here if I find it.

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> Jonathan.   | Barnes's Theorum:  For every foolproof device |
>             | there exists a fool greater than the proof    |
>