[Prev][Next][Index][Thread]
Cap Size
Hi all:
I've got my coil back in action with four banked 15kv neons at 30 ma
apiece. I'm using my old plate-glass-and-foil 90 lb cap which, when I
first designed it, was 0.02 + or -. The gap puts out a mighty roar
indeed, and judging from the temperature of the line cord (from a
microwave oven), it's drawing in the neighborhood of 18 to 20 amps.
I believe I have the coil in resonance. I don't really have a toroid;
rather, it's two 10" salad bowls tackwelded together at the bead. I get
a wonderful writhing display of corona off the bowls, especially at the
bead, and can draw out about a 14" arc at will. Despite my best
efforts, I can't get more, and yet, from what I am reading, with the 120
ma or so going in, I should be getting much longer discharges.
I was in the process of building my own a-la the 5 gallon bucket of oil
and hundreds of baggies and foil, but I opted instead to go for the
ready made variety -- seemed more cost-effective to me. I took the
plunge with the group purchase, but when it fell apart, I had second
thoughts. Now I'm wondering if I should go for the commercial cap to
see if it will improve the discharge. Am I on the right track, or is
this a matter of not having the right toroid, or perhaps cleaning up the
corona leakage? Or, is it the gap? I'm only using a simple series gap
with 1/4-20 brass bolts, which seems to work nicely, but nowhere near as
complex as the series gaps I've seen posted by Richard Quick. As I open
the gap, the discharge increases, but then I get ominous green flashes
from the cap. By past experience, this presages a punchthrough of the
plate glass and then -- dismantle and cut and paste to fit around the
shattered parts!
Any advice at this point would be much appreciated. I very much enjoy
the postings on this net, and of course am enthralled by watching my
coil do its thing in darkness!
Thanks again.
Stephen