You didn't say anything about the magnitude of the impact, but if it is
great enough, and you can modify or create the surface of interest, you can
use a technique we have used to detect baseballs, footballs, etc. thrown at
a target.

We made a "sandwich" from two pieces of Lexan, with a thin sealed air space
in between.  There are readily available small air-operated switches which
can be connected by tubing to the airspace, which will then give a
switch-closure on impact.  Surprisingly sensitive, but again, it depends on
just what kind of impact you are trying to detect.

Besides sensing impact, if the sandwich is well sealed and the "prolonged
pressure" is great enough, the switch will stay closed as long as the
pressure is applied.

If you are interested I can provide further details.

Foster

> -----Original Message-----
> From: pic microcontroller discussion list
> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of John Waters
> Sent: Sunday, June 24, 2001 12:03 PM
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [EE] impact sensor /pressure to volatge converter
>
>
> Hi all,
>
> I'm building a device to count the frequency an object strikes
> on, or rests
> on, a surface. I need a sensor that will sense the mechanical
> impact or when
> an instantaneous or prolonged pressure is applied on it. However, I want
> this sensor to work on its own without requiring any electrical power
> supply. Moreover, I want the sensor to give a voltage or current when it
> senses the event, the signal could just be instantaneous but must
> be strong
> enough to be used as an input to the i/o port of an ordinary
> microprocessor.
> Is this kind of "sensor", or more precisely, "pressure to volatge
> converter"
> available?
>
> Thanks.
>
> John
>
>
> _________________________________________________________________________
> Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
> --
> http://www.piclist.com#nomail Going offline? Don't AutoReply us!
> email listserv@mitvma.mit.edu with SET PICList DIGEST in the body
>
>
>

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body