Re: [TCML] Secondary and Primary Assistance

["DC Cox" <resonance@xxxxxxxxxxxx>]

Parallel copper pipes work fine.  Just blast 400-500 CFM of air thru them.
About the very best is a hyperbaric type sparkgap using an old vacuum
cleaner motor (your local vac cleaner repair shop should have a good
supply).  These provide great quenching and almost optimum performance
unless you go to solid state type sparkgaps using IGBTs.

Use a height/dia ratio for the sec coil of 4 or 4.5:1.  Use the largest dia
sec you can as the potential is Vsec = -L x dI/dt.  In short, keep the
inductance of the sec large.  Even with small NSTs a 6-8 inch coilform dia
gives excellent performance.  Most experimenters prefer around 1,000 to
1,200 turns for optimum performance.  Example, if you use a 6" ID PVC tube
with 6 3/8" OD, then with a 4.5:1 H/D ratio, this gives you a winding length
of approx 29 inches.  Divide this by 1,000 turns which provides a wire dia.
of .029 inches.  Use a "double build" enamel magnet wire such as
Polythermalize (Beldon).  Closest one for this example would be # 21 AWG.
You could also use 22 AWG.

Then use Bart's JAVATC to do all the calculations which gives res freq,
number pri turns, pri-sec spacing, cap size, coeff of coupling, toroid
capacitance, and everything else you need.  If you are not familiar with
JAVATC just fire me an off-list email back with your tel number and I will
call a guide you thru it.  After you have used it a few times you will just
love it.  Fast and extremely accurate, usually within 1/8th turn on the pri
tap!!

Regards and happy sparks,

Dr. Resonance




On 3/15/08, Mike H <mike8675309@xxxxxxxxx> wrote:
>
> I am very new to coiling.  It is something that my Father and I talked
> about doing many years ago, but never found time to do something like
> that.  Recently I found someone selling a coil they had started
> building, but hadn't quite completed.  He had all the components.
>
> Now last year I completed the construction and fired it.  It worked
> o.k., but I knew I really didn't know what I was doing.
>
> My main issue is I have a secondary that the original construction of
> is unknown.  Thus it is difficult for me to verify any numbers.  Also
> my secondary took some hits, and I would like to wind a new one. The
> actual device itself is also kind of large, so my goal is to re-wire
> everything to make it more compact, and then create a new primary and
> secondary that is optimized for the NST I have.
>
> So I find myself with 3 questions:
>
> #1- What is an optimum design for a static spark gap?  Copper pipes?
> Brass knobs?  titanium electrodes?
> #2- For my equipment, either What would my optimum primary layout be,
> or how would I calculate this?
> #3- Based on the primary design what would my optimum secondary be or
> how do I calculate this?
>
> Thank you for any assistance
> Mike H.
> Farmington, MN
>
> Details on what I have to work with:
>
> Some pictures of the components Here:
> http://s8.photobucket.com/albums/a23/tcw_fort/TeslaCoil/
>
> Video of the first fire last fall.
>
> http://s8.photobucket.com/albums/a23/tcw_fort/TeslaCoil/?action=view&current=TeslaCoilTests.flv
>
> Transformer is:
> Franceformer 12030P
> 120v NST 12000v 30mA, 360VA
>
> I am using a NST filter based on the Terry Filter design:
> 14 MOVS
> 12 CAPS 1.6KvDC
> 2 1kohm 100W resistors
> Dual Safety Gaps
>
> My Spark Gap
> Brass Cabinet Knob for Spark Gap - Microwave Fan
>
> Primary Coil
> 1/4 Copper Soft Tube
> 14.25" diameter coil
> 1" spacing from Secondary
> 13 turns
>
> Secondary Coil
> Unknown turns
> 16" of turns
> 19" Total Height
>
> Top Load
> Aluminum tape covered toroid made from MDF and 4" Aluminum duct
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
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