Conversion from sound wave to 12v signal/light

[RyleyMA61]

I am wishing to rig up a little system to the factory knock sensor in a 3T-GTE. I have been told they operate on a certain sound frequency from 1-15kHz?

I wish to connect a 12v light so that if the sensor picks up a sound wave at that frequency it will light up a little globe in the dash.

Is this the correct frequency range for hte 3TGTE and what sort of device would I be looking for? A trigger of some sort?

Thanks
Ryley

[Jasper]

A circuit based on this IC would be a good start:
http://focus.ti.com/docs/prod/folder.../tpic8101.html

There are designs for these circuits floating around, like this one.

[Norbie]

From what I understand knock sensing is a pretty complicated affair and involves a fair amount of signal processing to filter the sound of knock from the general background noise of a running engine. I don't think it's anywhere near as simple as you seem to be suggesting.

[ONCE-NA]

Like I told GW there is a mod to a VN knock sensor board that has been done, I think the article was in either Zoom, Performance build-ups, or street machine. a couple years back. I have the magazine but need the time to go through them all and find it.

[ONCE-NA]

Or, I have a factory 3T-GTE knock computer which you could prolly use the output to do something usefull

[RyleyMA61]

cheers guys. i think i did word my question stupidly, and rod is on the money of what i meant- maybe fuck with the output/signal/etc/etc on the stock computer so that it lights up a little light hidden in an air vent or something? or maybe so it sets a fire on the dash, that would get attention... ha ha!

[ONCE-NA]

Maybe find the wiring diagram for the factory knock computer and see what its output is and go from there...

[AeRoKaBn]

turboxs makes a knocklight which uses factory or separate knock sensor, lights up a led when it detects knocking, doubles as a shift light aswell!

http://www.turboxs.com/more_info.php?ID=212

id never thought about this before but i am very keen on it now

[ONCE-NA]

Yeah that looks like an alright bit of gear, what are they worth?

[AeRoKaBn]

$129US

i might try it out but thing that im not sure about tho is that when engine does start to knock the factory ECU pulls timing out to adjust. It has an amber and a red warning light, maybe the amber light indicates that theres slight knocking but ECU can handle it and when the red light comes on ECU's at its limits of pulling timing.

I only looked it up when i saw the thread so im not really sure how it would work with the factory ECU, might google a bit more no doubt some forums have some info on it