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Re: pure water capacitor?
Thanks for all the feedback. I figured that it really wouldn't work
effectively.
However, I talked to a chemistry professor today who thought that it might
work,
as long as the water is kept clean. He didn't think much about the
breakdown of
the metal plates, and I asked about it. The chem dpt has a brand new 18MegOhm
purifier (18MOhms per cm. breakdown voltage) that can supply me with vast
amounts of "free" VERY pure water. I was told that I would need to construct
it, clean it (including plates) many times, and rinse it even more times.
Then,
let it sit for a couple weeks, changing the water once or twice daily to
let the
ions in the plexiglass and plates leech out. After a couple weeks, a
relatively
decent equilibrium will have been reached (no more "excess" ions).
No one I talked to knew how the water would behave at resonance at 15kV. I was
pretty much told that I'd have to create one to find out. It would be rather
inexpensive to contruct one, considering the water is free to me.
But, I think I'd rather use an MMC, since they seem so great. I just
thought it
would be pretty sweet to have something different and unusual, since it's
eventually going to be given to the physics dpt (funded mostly by them, too).
Thanks again!
Mark
> snip....
>
> >I've been trying to do some research regarding design issues, when I came
> >across a list of dielectrics for some materials for use in capacitors. The
> >dielectric constant for pure water is around 85 with an infinite breakdown
> >voltage! This means that two 12" x 12" plates spaced 1/8" apart will give
> >a capacitance of .020uF! I thought it would be a pretty sweet idea: a pure
> >water cap in a plexiglass (or lexan (?)) box. But, I have NEVER seen this
> >mentioned anywhere I've looked. The only problem I can see is
> >contamination: everything has to be 110% clean before adding water. This
> >is do-able.
> >
> >Are there any reasons why I shouldn't try to use this?
> >