[Diy_efi] Re: Custom detonation detecting

[Phil Hunter]

> Date: Tue, 12 Nov 2002 11:51:09 -0500
???

As a starting point, my suggestion would be to look into Ion
Sensing, with it you s/b able to reliably see detonation on an
oscilloscope. From there you can build your DataAcq w/ confidence.
http://www.hut.fi/~vvartiov/ion/ion.html and
http://www.fs.isy.liu.se/~larer/Projects/main.html for starters.
Also, check the archives for Ville's posts.

My understanding is that the resonant frequency of detonation is
a function of bore diameter as the supersonic sound waves bounce
back and forth, so a Cavalier knock sensor is probably tuned way
off frequency. I'd investigate using a microphone and op-amp
active filters.

One thunk that just occured to me, use a "bucket brigade"
(switched capacitor) active filter as a kind of poor man's DSP,
clock frequency sets the center freq. of the filter, give it a
burst of clocks during the time of interest, output to a comparator
or some such. MF10 made by National Semi comes to mind, hafta give
that some more thought...

Sounds like a very interesting project, keep us posted.

rgds,
philh
(digest)

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