Re: Water As Dielectric [glycerine]

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: Re: Water As Dielectric [glycerine]
From: Tesla List <tesla-at-stic-dot-net>
Date: Tue, 11 Nov 1997 17:02:34 -0600
Approved: tesla-at-stic-dot-net

From:	Robert W. Stephens [SMTP:rwstephens-at-headwaters-dot-com]
Sent:	Tuesday, November 11, 1997 1:09 PM
To:	Tesla List
Subject:	Re: Water As Dielectric

> To:            "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
> Subject:       Re: Water As Dielectric
> Date:          Mon, 10 Nov 1997 22:36:57 -0600
> From:          Tesla List <tesla-at-pupman-dot-com>

> 
> From: 	Alfred C. Erpel[SMTP:aerpel-at-Op.Net]
> Sent: 	Monday, November 10, 1997 7:30 PM
> To: 	Tesla List
> Subject: 	Re: Water As Dielectric
> 
> AE>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> >     Is distilled water considered to be a viable dielectric material for a
> >plate capacitor? High voltage vs. low voltage? DC vs. RF?  Since it's k=80+
> >it would seem to be a good choice.  As a toolmaker, I would have no problem
> >making a sealed, watertight plexiglas cube, void of air, with evenly spaced
> >copper plates inside, and I would like to do this if someone doesn't tell
> me
> >it is a dumb idea.
> >     What is water's dielectic strength? I did a search on the internet for
> >this value and the only thing I kept finding was it's dielectric constant.
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<AE
> 
> DD>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
> Another fluid used in research is Glycerin, it's dielectric constant is
> about
> 40, as compared to water's 80.
> I've seen water used as a dielectric fluid and coolent, but only by running
> it with a pump through a small ion-exchange bed, to pick up the
> contamanents.
> Of course the general rule of thumb is that losses go up in propotion to the
> dielectric constant, so you might be shooting yourself in the foot, trying
> to use a high constant fluid.
> What we really need to find out is how dielectric loss is related to
> dielectric constant. Is it directly related to the polar nature of most
> of the high constant fluids, or does the complexity of the molecular
> structure enter into the equation ?
> If the former, we can lay to rest useing any high constant fluids forever
> and concentrate on building really nice vacuum caps for the ultimate in
> low loss.
> If the latter, we can search for, and perhaps engineer a proper low-loss
> fluid to do the trick.
> Anyone out there with a background in Physical Chemistry ?
> Daryl (who is dreaming of cheap, low loss, homemade caps...)
> <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<DD
> 
>     Ok, I think I've been convinced of the folly of using water as a
> dielectric, but now I am intrigued about glycerin. Can anyone report on the
> dielectric strength of glycerin or otherwise shoot down its potential
> efficacy as a dielectric? Again, my intent is to use it in a sturdily,
> machined/assembled, liquid tight, polycarbonate container .032 copper plates
> parallel and flat withing .002, with .010 to .030 even gaps between plates
>  depending on desired voltage/capacitance combination). Also what about
> ethyl alchohol as dielectric, which is between 35-40 k?
> 
>     Also, while on the topic of capacitors, I can't wait until I'm retired
> so I can build my 48" cube, 1 farad capacitor in my basement.  I'd charge
> that sucker up to 10,000 volts and go to sleep resting easy that I had 13.9
> kilowatt hrs. stored away in case I needed it.
> <seg>
> 
> Regards,
> Alfred
> 
> 
> 
>     Regarding capacitors in general
> 
> 
Alfred,

One of my lab technicians put some glycerine in our 0.1 inch 
commercial oil breakdown tester once and found substantial current 
flow at 60 Hz applied with the electrodes foaming with released gas 
microbubbles while the power was applied.  We thought to try this for 
capacitors once ourselves.  It apparently doesn't work.

rwstephens