Andy I sent this to you a week ago, maybe you didn't get it from the responses
I've been reading.
I've designed for some guy's doing simple vibration for sesimic detection
and the piezo's work well in detecting such in either microphonic or
displacement
(attaching
a weight to the element). Although we found it hard to repeat
calibrations
from unit to unit, it served their purpose. We contacted several
vendors, Murata,
Kyocera, etc. who manufacture them, but they only wanted to talk in thousand
unit quanities.
We bought in hundred quanities from a company called ALL ELECTRONICS
CORPORATION, in California ( 800-826-5432)
http://www.allcorp.com/
They are one of many surplus dealers and have seemed to be able to
continually
have the one we used in stock. A hundred 1.4" diameter units can be
purchased for
$65.00. They of course will sell in single units for a buck.
I have also used the Analog Devices the others have suggested and they
are great, but expensive as compared to the piezo. The impedance
of the units are such that
you can just about read them with a 16c7X device, but they really need
to be buffered with a amp or use a seperate A/D. I used a LTC1286 A/D to
get 12 bits of
accuracy.
Let me know if I can help further.
Andy Kunz wrote:
>I'd need only two one for starting my project
.
>where can I find murata on the web ?
>the chipdir contains only the name :(
http://www.future.ca
They rep them. Buy from your local Future/FAI office
Andy
==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
Hardware &
Software
for Industry & R/C Hobbies
"Go fast, turn right, and
keep the wet side down!"
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