And for our Next Trick ... How 'bout a diyTrionic?

[Robert Harris]

The disadvantage of an acoustical knock detector is that it detects the
"sound" of knocking, i.e. a certain frequency and type of noise that
unfortunately can be masked or enhanced by physical engine charactoristics
(aluminum, iron etc) and change's frequency etc by many factors and the fact
that ordinary engine noise has to be filtered out.

The Ionization Knock Detector looks for a specific event in the combustion
gasses - the sudden appearance of ionization products after ignition.  Since
this mechanism is not heavily engine material, size, fuel, temp, ambient
noise dependent for determining its characteristics, the detection of the
event is straightforward without the need of highly sophisticated self
anally extracting make TI rich DSP's.   Start with a clean signal and you
don't need the hi fangle BS to make the system work - a strange concept I
know but once upon a time was considered the way to do things.

Properly done, ION can work on everything from a lawnmower to a Multi-staged
turbo intercooled alcohol fueled road rocket without any basic changes or
tuning.  It simply must detect the knock related ionization event - which
incidentally will cause a low voltage dc conduction across the spark gap.
Simple.  Non computerized, wazoo ized and eminently doable without anything
even approaching a DSP.

> -----Original Message-----
> From: owner-diy_efi at efi332.eng.ohio-state.edu
> [mailto:owner-diy_efi at efi332.eng.ohio-state.edu]On Behalf Of Don Berry
> Sent: Monday, May 04, 1998 10:12 AM
> To: 'diy_efi at efi332.eng.ohio-state.edu'
> Subject: RE: And for our Next Trick ... How 'bout a diyTrionic?
>
>
> 		Has anyone considered use a DSP (digital signal processor)
> for acoustic knock detection? I understand that they can actually operate
> with a negative signal to noise ratio.
>
> 		Don
>
> 		...and no, my Chevy does NOT run Windows!  ;^)
>
>
>
> 		-----Original Message-----
>
> 		snip
>
>
> 		Cuz this tech sure looks like it beats the acoustic knock
> detection schemes by a Swedish mile!
>