You will be surprised about the "pressure computers", some tinny little
pressure components, gates, switches, that together can do complex
calculations and so on.  I don't know if they still in use, but I saw
some marvelous like that 15 years ago operating in highly explosive
ambient.

IBM was researching "light computers", an array of micro-optical devices
that used only a laser as its main power source. Gates and switches
change state when hit by a photons, and of course they allow or not
photons to go ahead... another science fiction turning to reality. Not a
single microampere of current in such high speed computer.


Spehro Pefhany wrote:
>
> At 11:50 PM 4/13/00 +0200, you wrote:
> >I4m working on a project where the customer don4t want electric connection.
> >And no batteries needing to charge, switch or anything like that either.
> >Too dark/small/dusty to use solar power.
>
> There are such things as air motors, used in process control equipment
> where electricity is too dangerous. I think the price may be too high
> for your application, though, and you'd need a generator too.
>
> An air-powered die grinder sells for about US$10 retail, Asian made,
> with the following specs:
>
> Operating pressure: 90 PSI
> No-load speed: 25,000 RPM
> Air consumption: 3 CFM
> Air inlet: 1/4'' NPT
> Collet size: 1/4''
>
> Maybe you could couple that to a generator to get the power you need.
>
> Best regards,
>
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> Spehro Pefhany --"it's the network..."            "The Journey is the reward"
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