VDGRF measurements

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <DR.RESONANCE-at-next-wave-dot-net>


A generating field mill electrostatic voltmeter is a good way to measure the
VDGRF output potential.  Some larger universities have them --- contact the
physics research dept.    You, of course, would probably have to transport
your VDGRF over to their labs.

Commercial power transformer test labs have a large resistive or capacitive
divider network with a toroid on top.  This measures up to 1-2 MEV range.

Ohio has a very nice HV lab.

These are some sources to try.

The problem with doing it yourself if that you need two nearly identical
spheres to insure even potential distribution.  It's usually easier to
calculate it.

With our work and different size terminals in the 14 inch to 40 in. diameter
we found that the output stabilizes around 26.5 kV/cm  which equals 67.3
kV/inch.  We use a standard ground terminal that is 1/3rd the diameter of
the HV sphere itself.

Best regards and be careful with the stored energy.  Even a small 14 in.
sphere has a peak current of around 4 Amps!!

Regards,

Dr. Resonance

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, July 18, 2002 5:06 PM
Subject: Re: Natural streamer :)


> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>
>
> Tesla list wrote:
> >
> > > If you have an easy way to measure the terminal voltage of a
> >
> > > large VDG I'd be interested to know it.
> >
> >         'easy' is a relative term...
> >         I have a couple of pro HV Research Engineering books
> >         with whole chapters theron.  Whether 'easy' applies
> >         to any of those techniques is up for discussion....
> >
> >         An old article on van de Graaf construction included
> >         building a longgggggggggggggg string of hi meg
> >         resistors, driving a uA meter, with the other side
> >         grounded.  By use of MANY resistors, the breakdown
> >         voltage was distributed...  Use of a uA meter kept the
> >         van de Graaf in its normal operating mode.
> >
> >         May be something wrong with that, but I can't think
> >         what....
> >
> >         best
> >         dwp
>
> The last scheme is OK in principal, if you had a large source of very
> high resistance devices, which you'd probably have to run in oil for
> corona protection.  I don't consider that easy.
>
> Ed
>
>
>
>