RE: Stumped at first light

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>

.066

I already see two possible problems:

1.  Your primary doesn't seem to have enough turns.  You should probably go
for about 12-14 turns ideally.
     Also, 1/4" of spacing between turns should be plenty for this coil.
This will keep a 12-14 turn primary
     to a respectible size.

2.  Strike Rail - Although you didn't mention it, you need to make sure your
strike rail IS NOT continuous.  It should
     have a 2-4 inch gap.  Remember, you are basically added a short circuit
to your magnetic circuit with a continous
     spark rail.

3.  Capacitor Size - For a 12000V, 30mA -at- 60Hz NST, you should be looking
for around a 0.066uF capacitor.

Dan




    My class has built most of our coil and I am a little sceptical about
our capacitance calculations. We would very much like to fire it up, but I
think it needs a little fine tuning. Here is what we built: feed-12000v NST
-at- 30ma, adjustable spark gap built out of copper tubing, The primary is 6
turns of 1/4" copper tubing with a 3/4" gap between turns, the secondary is
1000 turns of 22 ga. magnet wire on 4" pvc with a heighth of 26 5/8". We
have an 8" gazing ball or 4" aluminum flex duct for a topload. We built a
strike rail around the primary out of  #2 bare copper. Will this work, and
what kind of capacitors do we need. Any help would be greatly appreciated.
Thanks.