RE: 600kV voltmeter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 15 Mar 2005, at 17:02, Tesla list wrote:

> Original poster: "Derek Woodroffe" <tesla@xxxxxxxxxxxxxxx>
>
>
>  >This spark length is measured from the toroid to a 7-12 inch ground
> terminal.  It may then be compared
>  >with the peak DC potential charts in the Handbook of Chemistry &
>  Physics.
> Use the standard impulse
>  >generator chart for best accuracy.
>
> Ouch That Hurt.. :-/
>
> That method is so simple and obvious , its brilliant.. Why the heck I
> didn't think of it before.
>
> What's more embarrassing is the calculations and other complex methods
> of determining the Vout of a TC that I have tried in the past.
>
> Derek

I mentioned the lack of correspondence between sparklength in
repetitive operation and voltage in my 1995 article. A lot of the
"operational research" for that article involved operating a coil in
both repetitive and single shot modes. Claims of MV outputs were ripe
for busting at the time. It was obvious that short coils would simply
flash over from top to bottom in single shot mode if Vout was high
enough to permit and it was easy to make coils do this in practice.
     Following on from that I hunted out and pored over available
literature (pretty scant in NZ) and found that the correspondence
between Vo and the capacitance ratio of sec-pri was mentioned in a
pamphlet entitled "Tesla Coil Secrets" (Trinkhaus or was it Ford?) or
something similar. It was pretty clear at the time that the single
shot sparklength told a far more accurate story re Vout than running
at PRF's of 100+.

    FWIW I discovered on reading the CSN that Tesla at one stage used
the lumped formula to describe Vout.

Malcolm