[Diy_efi] Ion Sensing project

Bruce nacelp at bright.net
Thu Jul 4 17:37:09 GMT 2002


----- Original Message -----
From: "Ville Vartiovaara" <vvartiov at cc.hut.fi>
> Misfire detection doesn't have to be that late.. The system should first
> (just after spark) detect if the flame term of the ion current signal is
> missing, i.e. the signal doesn't start rising fast enough. That's a lot
> before TDC, especially at misfire-prone light-to-medium load.

Ah,
I was worring about things at WOT,
ya, with a lean cruise, you would have lots of advance and time for sensing.

> Actually, I think some implementation of this has been done.. Not sure, at
> least it was discussed in some of the papers around.. It's much simpler
> than the actual PPP estimation..
> > > The problem with CDI is usually the ringing on the HV side after the
> > > spark, which may corrupt the ion sensing process.. But this is just a
> > > misfeature of the cap and coil and bad design..
> > Can you give a simple explaination why a CDI would have more ringing
then a
> > conventional setup?.   It would seem to me, that with a faster rise
time,
> > there would also be a faster decay.

> Decay is definitely faster, but self-induction in the coil will charge the
> capacitor a bit backwards if the control doesn't cut the path soon enough.
> The effect is plain self-resonance of a LC circuit, and has a clear effect
> when measured.. A plain coil (conventional layout with no capacitor to be
> recharged) has so minimal capacitance at the leads that ringing is
> neglible.

Thanks, *even I got that* <g>.
Which generates the next guestion, of what's inside a GM smart coil,
condenser wise?.
Bruce



_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi



More information about the Diy_efi mailing list