RE: Desktop Bipolar Coil

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

Original poster: "John H. Couture by way of Terry Fritz <teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Dave -

That Maxwell cap comment was in reference to coilers who enjoy a "money is
no object" attitude with Tesla coils. One of the facts of the TC world is
that it takes better quality and more expensive materials to obtain longer
sparks. I have never used an MMC cap but I understand they are as good and
less expensive than a Maxwell cap.

Spark length vs watts input is a tricky business especially with random
spark outputs. Using a random output for a standard is nonsense engineering.
However, I admit I use it for one of my computer programs because it is
accepted by coilers. It is my understanding the John Freau's equation for
spark length is only good for NSTs when the NST is modified.

John Couture

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-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, June 27, 2003 1:24 PM
To: tesla-at-pupman-dot-com
Subject: RE: Desktop Bipolar Coil


Original poster: "Dave Kyle by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dave-at-kyleusa-dot-com>

Hi John,

Thanks for the very cool picture; it will no doubt provide me additional
inspiration. It is very similar to what I have in mind though I plan to use
modern materials.

But why a required transformer mod and $500 Maxwell cap? Based on the John
Freau's equation a 7.5KV -at- 30 could yield as much as 25.5 inches with a 120
volt input. 18 inches would then seem to be very much in reach. Are you also
saying an MMC will not work in this application?

Dave

=========================================
Dave Kyle
Austin, TX USA
Email: dave-at-kyleusa-dot-com


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, June 26, 2003 9:07 AM
To: tesla-at-pupman-dot-com
Subject: RE: Desktop Bipolar Coil

Original poster: "John H. Couture by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Dave -

Click on

      http://www.mgte-dot-com/tesla/tesla1.htm

for a bipolar TC coil with 7.5KV/30ma NST. This coil was an antique with a
Litz wire secondary but regular magnet wire will work as well. To get an 18"
spark the TC will have to be optimized by rebuilding the NST and using a
$500 Maxwell capacitor!

John Couture

-----------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, June 26, 2003 12:43 AM
To: tesla-at-pupman-dot-com
Subject: Desktop Bipolar Coil


Original poster: "Dave Kyle by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dave-at-kyleusa-dot-com>

I have some extra parts and was thinking of a small coil project that could
be run without grounds and counter poises. I also wanted something that
could be potentially run in the house with less risk to all the electronic
appliances.

A bipolar arrangement seems the logical choice. Rather than the popular twin
arrangement I am looking at a single horizontal coil and thought it best to
seek some advice.

Some initial design thoughts:

24 x 3.25 inch secondary wound with 30 gauge wire (2,O00 turns)
A classic 12 inch helical primary centered on the secondary
Propeller style SRSG
.025uf MMC LTR
7.5KV at 30ma nst
Raised 6 inch spheres on ether end of the coil provide a fixed 18 inch gap

I have run the numbers and they look promising. I expect it to make sparks
that will easily jump the 18 gap. Worse case I could always throw a 9KV nst
at it if the output was disappointing.

The number of turns on the secondary seems high but when thought of as two
separate coils is about right. Is my thinking here correct?

Your thoughts and comments would be most appreciated.

Dave


=========================================
Dave Kyle
Austin, TX USA
Email: dave-at-kyleusa-dot-com