Original poster: "D.C. Cox" <resonance@xxxxxxxxxx>
It's approx 70% of the value of a full sphere which is 30kV/cm. You
use the minor dia of the toroid as the "sphere" dia. If theese is a
re-entrant hole in the sphere the value becomes 26.5 kV/cm for the
potential measurment.
We've measured this by comparing CIV (corona inception values) of a 7
inch sphere and a toroid measuring 30 x 7 inch. The CIV point was
determined when RF interference started forming on a scope hooked up
to an amplifier.
Dr. Resonance
Anyone know the equation for how to determine the maximum voltage a
toroid can hold before breaking out.