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Re: Tesla Secondary Dilemma

At 07:32 PM 5/5/99 +1200, you wrote: 
""
I think my TC secondary has too many turns on it. I made the secondary out
of a 26" long, 5.5" (outer diameter) PVC. The winding is 22" long. Trouble
is the magnet wire I had was 0.16mm diameter, which translates to 50-60
turns per cm, or 125-150 turns per inch. Thus there are around 3000 turns
of wire on the secondary. I gather this may be too many turns. Can this
secondary be saved !!!!
As you can imagine I'd rather not wind another, and this one is so pretty.
Any suggestions anyone?
""

Here's what I think,

22 inches long, 5.5 inches in diameter and 3000 turns gives an inductance
of...  (wheeler) 278 mH.  Assuming a mid size top torroid and guessing at a
few dimensions, my E-Tesla program predicts that the Fo frequency will be
around 63kHz.  If you ran with a 60mA neon and have a primary cap size of
10 nF, you would need a primary inductance of 637 uH which is very high.
The primary would have dimensions similar too:

inner diameter 7.5 inches
turns 34.6 at two turns per inch.
outer diameter 42 inches.

Sooooo, You would need a very large primary coil to get the coil's
frequency down low enough to drive this very high inductance secondary
coil.  You may be able to go to a larger primary cap which would reduce the
size of the secondary too.

To make a long story short, that primary is going to operate at a very low
frequency and you are going to have a challenge coming up with an equally
low frequency primary circuit in reasonable dimensions for you coil size.
You would probably be best off by just using a coil of thick wire as the
primary and not worry too much about making a spiral or anything like that.
 This will have more loss than most coils but a big coil of wire could get
you to the high inductance needed in a relatively small space.

At least this is my quick shoot at answering your question...

	Terry