impact sensor /pressure to volatge converter
Chris Carr email (remove spam text)
> Chris Carr wrote:
> > I cannot think of any means of detecting the presence of a steady load
> > which uses no electrical power. I can only think of purely mechanical
> > ones i.e. a set of scales.
> Actually there was a kind of scale called a servo scale (with remote
> reading) which used a normal scale & spring mechanism with a bilateral
> switch attached and a servo used to null the switch. This could be called
> a 'zero power' scale. (the servo was used to reduce error due to the large
> forces in the mechanical transmission to the readout - it was a
> differential Bowden wire transmission). At least 60 years ago.
Thanks for that Peter. I can sort of visualise it. I don't suppose there is
a picture anywhere on the net.
The words Pneumatic and Hydraulic sprung to mind as transmission media. But
then again Servo. How about putting two Stepper Motors back to back. One of
the motors being remotely located. With a mechanical arrangement to turn
vertical movement due to a load into rotary motion. Rotary motion turns
motor creating electrical pulses which causes stepper motor at the remote
end to turn in sympathy.
There's a web site somewhere showing it, I thought I had bookmarked it, but
I cannot find it now. No, it doesn't appear to be on Dougal's Browser nor on
Bryan, Dylan, Ermintrude or Florence. Bloody Typical. Anyway I did try it
and it does work without any amplifiers just by connecting the leads back to
back. I see know reason why this arrangement should not work over longer
distances if driver amps are used at the receive end, or feed the pulses
into a PIC.
Perhaps John Waters would like to experiment to see if it would work, and do
us the honour of providing some feedback. It strikes me as being a Student
Project anyway due to the vagueness, as he has not responded to requests for
more specific details, and he hides his identity behind a Hotmail Account.
http://www.piclist.com hint: To leave the PICList
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