RE: Coil Frustration

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

Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pkomen-at-zianet-dot-com>

Hello,

I'll try to answer though I have little experience.
Resonant cap size for you transformers is 0.012uF.  0.02uF would be OK for
LTR (Larger Than Resonant).  Are the caps in series or parallel?
1500V caps are getting about 14,142V peak. (square root of 2 times RMS
voltage)
Assume 963 turns of #22 wire (or 26 inches of #22) and a toroid of 4" X 17"
(guessing from your picture) the secondary resonant frequency is 109 KHz.
No toroid (using coil formula and Medhurst) gives 176 KHz.
Estimating the primary as 20 degree cone with 1/4 inch tubing on 3/4 inch
spacing with the caps in series gives a primary freq of  292 KHz.  Caps in
parallel gives 146 KHz.  (using all 7 turns of the primary)

I think you need more primary turns and higher voltage caps.

Please supply all the measurements on your coil for better calculations.
Some of the more experienced coilers can offer better calculations too.

Regards,

Pete Komen

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Tuesday, June 26, 2001 9:16 PM
To: tesla-at-pupman-dot-com
Subject: Coil Frustration

Original poster: "CJ Moore by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<wizard1234-at-home-dot-com>

I am somewhat of an amateur builder. I have made 2 coils. 1) was horribly
pathetic and I won't even discuss it
however, the second was in my opinion a decent small coil.

Powersupply - 2x Ignition transformers 10 kv 23 ma (in parallel_
Spark gap - series 4 bolts total gap of about .5 inches
Capacitor - 2x .02 uf 1500 kv
Primary - 7 turns of 3/4 inch copper refrigerator tubing (rising pancake
form)
Secondary - 26 inches high 9 inch diameter wound with 22 gauge wire
Toriod - Ventilation Duct (didn't work at all) just went with a copper
terminal.
2 RF Chokes which were just pieces of pipe with about 200 turns of 22 gauge
wire on them.

With this system running, I would get a faint (really really faint) corona
around the terminal, and if I put a grounded wire near it, maybe a 4 inch
arc.

I have seen other coilers pages and pictures and some people have built
coils
very similar to mine, but with much much better results, please tell me what
I
am doing wrong!

Here's a link to some pictures of my coil.
I have made some modifications (but don't have pictures) This is my first
spark
gap, not the one I use now. Don't think the transformers are hooked up
correctly.
Just for a general idea.
<http://members.home-dot-net/fredmoore/>http://members.home-dot-net/fredmoore/