Here's a link to a commercial product: http://www.turboxs.com/more_info.php?ID=212
There is a downloadable installation guide there. It appears from this that it's a bit of a complicated issue. It looks like a series of maybe two or three acoustic filters would be necessary to remove the normal engine sounds from the audio stream (signal from the sensor) and those filters would be different from engine to engine, or at least require custom configuration for each engine model. Then the remaining noise (knock) could be detected with a comparator, it's output fed to a lamp/buzzer driver, etc. This appears to be what the folks at turboxs have done. Thus far I have not found any specifics regarding the frequency response of the sensors: A properly set up sensor could include the necessary frequency response filtering already, simplifying the tuning issues. jg On Wed, 2008-12-10 at 21:18 -0800, George Bearden wrote: > I have never fooled with knock sensors. I did read up on them several years > ago. What struck me was the assertion that a knock sensor from one model of > engine can't be expected to work properly on a different engine. It was like > they had to change the knock sensor functionality when they made possibly > even minor changes to the engine. The natural frequency of each engine type > (do they REALLY have a natural frequency?) is such that detonation just > doesn't sound the same from engine to engine. > > I no longer depend on my memory... So I suggest doing some research. Very > interesting topic too. > > GeoB > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
