In article .com,
wrote:

Well this is a question I have about usb and water.
The company I work for just bought a new Waterjet machine (it use's
water and garnet to cut pretty much anything up to 9 inchs thick in a
tank full of water).
It is computer controled and use's a waterproof keyboard to move the
"head" to a location of your chosing. The machine can cut a sheet of
steel 80" by 160" and some times there is a need to "reach" the other
end away from the keyboard. The company that makes the machine offers a
"remote" keypad for $500. Well, it's a steel box with a waterproof
numaric keypad bolted in it and uses a usb extention cable to conect to
the pc.

OK that said.

1. Does anyone know of a "standard" waterproof numeric usb keyboard?
(i've googled all over and no luck)
2. If a non waterproof keyboard "shorted" would it trash the
computer?(well that would just be a very bad thing)
3. Is there such a thing as a "fused" usb cable,adapter or hub?(going
with the idea of using a non waterproof keypad and if it did "short"
the "fused" part would keep the computer safe)
4. uh....anyone have any other ideas???



Thanks for the help
Steve

Try the search terms (on something like altavista.com) :

waterproof industrial keyboard

As for industrial safety, you can never be too safe. It would be
difficult for us to do a safety analysis at a distance. Maybe
damaging the computer is the least of your worries (like providing
a ground path for the dude reaching into the tank).

Bluetooth is a wireless standard for things like keyboards.
But how clear would the RF spectrum be in your work
environment ? How often could you afford to fiddle with
batteries ? If the purpose of this keyboard, is to stop the
machine, I'd pay the $500 :-)

On Asus motherboards, the USB +5V source is protected by a polyfuse,
which is a self recovering thermal based fuse. It limits the
amount of +5V that can flow. But the data pins D+ and D- are
pretty ordinary looking I/O pins, and taking them to voltages
outside the normal logic range, could I suppose damage them.
I/O signals are usually protected by clamp diodes, and once
the current flow into the diodes exceeds 20mA, they can be
damaged. If a short involves 120AC getting connected to D+ and
D-, then I don't know what to tell you (what color smoke would
you like?).

Another thing you could experiment with - try connecting
multiplie USB keyboards to your computer. Do all the keyboards
continue to work, allowing input from any keyboard ?
If they do, perhaps you could build permanent pedestal
mounts for several keyboards, eliminating the possibility
of the keyboard falling into the tank. The keyboards
still would have to be waterproof and moisture proof,
preferably with a depth spec (to prevent cheaters, product
makers that are "water resistant"), but at least then you wouldn't
have to consider the case of the keyboard device falling in
the tank.

For the amount of nuisance involved, the $500 is well spent.
I'm not a lawyer, but I'd want to understand the liability
issues involved around a thing like this. If you rig up
a kludge, who gets sued ?

Paul