RE: Distilled water as a dielectric?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx>


Greg:

All of my caps are parallel plate.  Most of the guys on this list have
shifted to mmc's because they claim they are cheap, but I have found
mmc's to be very expensive compared to my parallel plate units.  Also, I
can change capacitance in small increments very easily.

My caps use aluminum flashing alternated with dielectric layers of mylar
polyester.  Each dielectric layer of mylar is (6) 3 mil mylar sheets.  I
think the puncture voltage is around 30 KV for this design(20KV blew
thru (4) layers during a single layer test).  My largest cap to date is
38.5 nF and consists of (24) dielectric layers and (25) conductor
layers.  It is assembled one sheet at a time under oil to avoid the need
for vacuum evacuation.  It all fits in a Click-Clack air tight food
storage box(Conductor area 9"X6" - Overall dimensions 11-1/2" X 8" X
1-1/2" tall).

Mark



-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Tuesday, May 31, 2005 8:24 PM
To: tesla@xxxxxxxxxx
Subject: Re: Distilled water as a dielectric?


Original poster: Greg Morris <gbmorris@xxxxxxxxx>

Alright, thanks guys, that's exactly what I wanted to know. Any
suggestions
on what I should use for a dielectric, that would be cheap, easily
obtained
and work well? How big do parallel plate caps usually have to be anyway?

Has anyone here made any?

On 5/31/05, Tesla list <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
wrote:
>Original poster: dave pierson <<mailto:davep@xxxxxxxx>davep@xxxxxxxx>
>
>
>
> >The problem is that it is hard to make deionised water stay
> >deionised.  Once you put ordinary metal contacts in the water and
> >pass a current you start to get ions.  There are dissolved gases such

> >as CO2 that dissociate into H+ and HCO3- that can combine with
> >metals. In some casual HV experiments with deionised water open to
> >the air the conductivity increased over a day or two.
>
>     Just so.
>     I've mentioned visiting the HVDC power inverter: they chop MW of
> +/-500KVDC
>     back to AC for the net (including some of what i use to send
>this....).  The
>     main insulator/cooler  is 99.999ifergethowmany9s water.  The
>purifier/deionizer runs
>     constantly stripping the stray ions back out...
>
>     best
>        dwp
>
>