Piezo Electric accelerometer??

[Frederic Breitwieser]

>Am I correct in reading this to mean one or the other,
>depending on application?  The Piezo electric device acts
>like a microphone, correct?  Or can it be called an
>accelerometer, and if so, why?

Piezo electric elements, irregardless of use, generate a varying voltage
depending on how "bent" they are.  Piezo microphones generate a voltage
based on the same principle.  You speak, the sound waves bend (resonate)
the element, and a voltage is created.

An ESC sensor is a knock sensor, which is basically a microphone, the
engine knocks, the block is an excellent conductor of sound, and the ESC
sensor picks it up and generates a signal, which the ECM uses to retard or
advance the timing.  Really clever ECMs, like some of the aftermarket ones,
can determine which cylinder is knocking, and retard _just that one_
cylinder causing the problem.

OEM just plays with all of the cylinders, at least the GM units I've seen.


Frederic Breitwieser
Bridgeport, CT 06606
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 4-Door Softtop Humvee (Hummer)
2000 Buick GTP (Mid-engine track car)

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