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Ross-O's 1st Run - secondary arcing
I made my 1st run of Friday night. I managed 31" arcs to a grounded rod
before secondary arcing convinced me shut down. Here are the specs for
my coil along with my Tesla URL. Please forgive the large pictures and
slow loading of the page, I'm working on it...
Primary: 15 turns of 1/4" copper tube with 3/8" spacing on a 45 degree
angle
Secondary: 6.275" SDR wound to 25.1" with #22 magnet wire
Capacitors: .060" LDPE rolled cap, used .027uF for this run
NST Bank: 12 kV -at- 106 ma
Torroid: 7" aluminum dryer ducting, total OD is 29.5"
See the page for pics and more details
http://www.geocities-dot-com/CapeCanaveral/Cockpit/3377/
I only managed to tune to the nearest turn before secondary arcing
forced me to shut down. I had a heavy blue cone of corona from the top
turn of the secondary down to the strike rail. It looked neat, but I'm
afraid that the excessive ionization around the secondary may have
facilitated the arcing problems. The 1st arcs originated from a
"fisheye" in the varnish about 6" from the top of the secondary and shot
straight down the coil to the ground connection. I put a couple layers
of electrical tape on top of the bad spot and kept running. I noticed a
few more of these coming from other locations. I raised the secondary
about .75" and got a different sort of arc. This one came from the top
turn of the secondary and only went down about 6". It formed a large
brush shape almost as large as your hand. I quickly surrendered for the
night.
The good news is the 31" arcs while still somewhat out of tune. I was
able to light a neon "R" at about 10' and could make a 4' fluorescent
tube glow over 20' away! It's a beautiful thing - the sound, the light,
the smell, all of it! Guess you could say that I'm thoroughly addicted.
I had a hard time getting breakout without using a sharp point. I
managed it twice before I shut down, and both times it came from the
rough seam of the torroid. It seemed to prefer to break out on the
secondary instead of the torroid!
I fear that I may be overcoupled with the 45 angle on my primary. I can
raise the secondary if I need to. Maybe I need to lower the torroid or
make it smaller? I could get rid of several turns of primary and drop
the ground rail several inches to help reduce the corona cone. I am
really excited about running this thing again and could use some advice
from you experts on how to solve this problem :-)
I really want to thank all of the people who contribute to this list,
especially the moderator (Hi, Terry) and the TCML webmaster (Hi, Chip).
I have learned tons from this list and the archives. You all have also
provided much needed inspiration during the sparkless months. The
internet is a truly beautiful thing!
Feel free to respond off list to <ross-o-at-mindspring-dot-com>
Constructive criticism always welcome.
Ross Overstreet
Huntington Beach, CA