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Re: Your Spreadsheet
Subject:
Re: Your Spreadsheet
Date:
Mon, 17 Mar 1997 13:30:21 -0500 (EST)
From:
Esondrmn-at-aol-dot-com
To:
jim.fosse-at-bdt-dot-com
CC:
tesla-at-pupman-dot-com
In a message dated 97-03-14 14:49:46 EST, you write:
<< >
I'm going to have to build a new coil. My current coil is up to 52"
(straight line measured) arc to a ground rod at ~2KVA. But if I take
off the discharge point from my toroid, I get instant discharges to my
strike rail, secondary flashover and christmas tree corona from the
secondary. I'm using a 30 degree conical primary and have had to raise
my secondary up 4.5" to lower the coupling. It's still to high, so I'm
going to rewind my primary as a flat spiral. I'll use your program for
the calculations.
I'm also thinking of building a new secondary with a higher resonant
frequency so that I can use less inductance in the primary for a lower
surge impedance.
>>
Jim,
I have a similar problem with my 6" coil, running at 5 ot 8 kva. The
longest
discharge I have measured is 80" to ground. My primary is 3/8" copper
tubing
wound at 30 degrees, with a stirke rail about 2" above and slightly
outside
of turn 14. I have the same problem with stirkes to the primary/strike
rail.
I do wish I would have wound a flat primary to begin with - but at that
time
I thought I would be happy with neon transformers and 48" sparks.
I have learned something from the 3" coil that I recently built. If I
put
the smaller toroid on the secondary to provide shading, then set a beer
can
on that and the larger toroid on top of that, almost all the discharges
leave
from the upper toroid. I will try this with my 6" coil once the weather
warms up. I will place the 30" toroid on first then use foil covered 3"
dia
plastic pipe to mount the 40" toroid on top of that - probably up about
another 12".
Ed Sonderman