Larry Cochrane wrote:

> Some comments;
>
> Besides the cost of the part there is still more electronics that would be
> need to make the chip device into a real sensor. One still needs buffering,
> filtering, power supply etc. Since some external electronics is needed, why
> not also have all of the parts needed to make a complete sensor on it and
> make the mechanical part? Maybe the device could also be sold as a kit, if
> it's not to hard to make. In fact, if its too hard to make then it will
> probably be hard to produce, so it needs to be as simple as possible.
>
> We have a lot of clever people out there I'm sure we can come up with
> something....
>
> Regards,
> Larry Cochrane
> Redwood City, PSN
>

Ok Larry now I see where you are coming from.
Only covering the strong motion range say +/- 2 g it is not hard to come up with a
lot of different ideas for sensor. The real challenge as I see it is in the
details of the design. That is picking a design that is easy to manufacture the
parts or using a design that can be build from common parts such as the STM-8.

The very first sensor I built consisted of a small weight glued to the cones of
two speakers. It easily detected footsteps across the basement on a concrete
floor.

We should try and nail down a few specifications so that the discussion don't get
too far out in left field. How about +/- 2 g max acceleration with 16 bits of
dynamic range. (How does this match the low end of a geophone sensitivity?) What
about frequency response? ( 0.01 to 10.0 Hz).

--
Jim Hannon
http://soli.inav.net~jmhannon/
42,11.90N,91,39.26W
WB0TXL



_____________________________________________________________________

Public Seismic Network Mailing List (PSN-L)