[sdiy] flexible resistors?

[harry bissell]

You can make a DIY pressure sensor out
of black conductive foam for storing
IC's.

There was an old Ideas for Design on this subject...
I'll try to find it.

H^) harry

--- Josh Landau <jslandau at engin.umich.edu> wrote:
> 
> >Some trucks use strain gauges to measure axle load.
> Strain gauges are also
> >used to measure the volume of nasty stuff in a
> vessel. How much pressure on
> >the supports? Outputs are low. Use a differential
> amplifier.
> 
> FWIW... I spent this summer doing R&D on human
> weight measurement systems 
> using strain gages... nasty stuff, when you really
> work with it.  Very low 
> level signal, pretty noisy.
> 
> That said, some other gage manufacturers are
> Panasonic and CTS.
> 
>  >     Yep, sure is.  One name is "strain guage". 
> You can also get resistors
> > > that vary with pressure.  Never played with
> them.  But, if you look hard
> > > enough, you will find them.  I don't think they
> are cheap...
> 
> A strain gage is a resistor that varies with
> pressure.... the traditional 
> method of using them is to put them in a half or
> full Wheatstone bridge, 
> use a diff amp on the output, and then do massive
> signal conditioning on 
> the diff amps output to recover a usable signal. 
> Dunno about pricing... my 
> employer got good prices, but they were buying in
> large volume....
> 
> But relating the pressure change to flexion may be
> more difficult.
> 
> Josh Landau
> 
> 
> 


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