RE: 600kV voltmeter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>

>That method is so simple and obvious , its brilliant.. Why the heck I
didn't
>think of it before.

Yes, it's a great method for OLTCs, DRSSTCs and the like. You don't even
need to modify the power supply for these, they can be made to run in single
shot mode by adjusting the trigger electronics.

I used it a lot in my OLTC work a few years back, the only difference being
that I used two pointed electrodes instead of two spheres, and a table
published for breakdown between pointed electrodes. This was because I
didn't have two spheres handy.

The answers came out within about 10% of what I expected the voltage to be
based on conservation of energy. (1/2*Cpri*Vpri^2 = 1/2*Csec*Vsec^2)
Changing the ring-up time (and adjusting the DC link voltage so as to keep
the peak output voltage constant as measured by an E-field probe) did not
have any measurable effect on the spark length.

I believe you can also use your toroid as a kind of voltage indicator
provided it is smooth. Toroids have a theoretical breakout voltage that
depends on their dimensions, which Antonio de Queiroz's INCA program will
calculate for you. For instance, if my big coil (which has a 8" x 24" spun
toroid) breaks out at all, I know it must be producing around 600kV.

Mind you I suppose that figure has fallen somewhat due to the scratches and
dings the toroid has picked up over time.

Steve C.