User-agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0
Em 10/07/2014 13:42, Carl escreveu:
Hey--
A sphere will break down at a voltage of 30,000 * r(cm) at sea level.
A cylinder of the same radius will break down at twice the voltage, if
you can protect the ends. The toroid neatly eliminates the end
problem by eliminating the ends, and the breakdown voltage will be the
same as the cylinder it's made from, minus a small kludge constant due
to the major curvature. So a toroid of 3" small diameter will break
down at a little lower than 300,000 volts at sea level. At higher
altitudes, subtract 10% from the breakdown voltage for every 2200 feet
of altitude ASL up to about two miles high. When any kind of breakout
point is used, it's Katie bar the door.
Trying some calculations of toroid breakdown voltage using the exact
formulas implemented in the INCA program:
Minor diameter: 0.1 m
Major diameter (m) and breakout voltage (kV):
0.200 226.21
0.400 328.92
0.600 400.64
0.800 455.32
1.000 499.23
1.200 535.75
1.400 566.93
1.600 594.05
1.800 618.01
2.000 639.43
10.00 951.80
100.0 1337.91
1000 1691.80
By the rule of 6000r kV, the breakdown voltage would be of 600 kV.
Reasonable for a wide toroid, exact for a 16.48x1 toroid.
About smoothing of irregularities, I imagine that the cause is ionized
air around the irregularities.