Re: [TCML] largest secondary coil you'd drive with an NST

[resonance@xxxxxxxxxxxx]

4:1 to 1 or 5:1 seems to work great.  Optimum value based on max
inductance is 0.9 but this will arc over.  I always use 4.5:1 for classic
coils and 5:1 for solid state coils.

Dr. Resonance


> I hate to ask this too - but what is the optimum aspect ratio for a
> secondary?  I've run JAVATC, and have built a feeble (but pretty) classic
> tesla before ... and have read but probably poorly understood a few
> papers.
> I think that I'm ready to build version two of the static-gap,
> NST-powered,
> properly filtered and protected coil.  I just want to make sure that I
> learn
> as much as possible before I start purchasing things that probably won't
> suit my needs.
>
> On Dec 13, 2007 5:56 AM, David Rieben <drieben@xxxxxxxxxxx> wrote:
>
>> Hi Tim,
>>
>> It's a bit of both ;^) As the power levels increase, this calls
>> for larger circuit components (primary C and L and conse-
>> quently larger secondary C and L). Of course there is some
>> flexibility to these parameters and you can increase the output
>> of any given coil by applying more power, within reason.
>> However, a larger diametered secondary coil has a greater
>> inductance than a smaller one and will therefore yield longer
>> sparks. For example, a 12" diameter secondary coil will
>> yield longer ouput sparks than an 8" diamter secondary coil
>> from a 10 kVA power source, assuming all other aspects
>> of the coil are identical. Of course both coils will produce
>> longer sparks from a 10 kVA power source than from
>> a 5 kVA power source. If you are sticking with NST
>> power, then 6"  should be as large as you should need
>> to go for secondary coil diameter. If your going with pig
>> power, then you should opt for at least a 10" diameter
>> secondary coil, if not 12" or more to properly utilize the
>> available power. As far as height goes, optimum aspect
>> ratios (height vs diameter) are generally between 3:1 and
>> 5:1 with the larger coils generally falling toward the lower
>> range and the smaller ones to the higher range. You should
>> choose a wire size that will allow you to wind 1000 to 1200
>> turns while maintaining the secondary's dimensions within
>> the optimum aspect ratio.
>>
>> Hope this helps,
>> David
>>
>> ----- Original Message -----
>> From: "Tim Meehan" <btmeehan@xxxxxxxxx>
>> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
>> Sent: Wednesday, December 12, 2007 8:20 PM
>> Subject: [TCML] largest secondary coil you'd drive with an NST
>>
>>
>> > Is there some given maximum size of secondary coil (diameter or
>> height)
>> > that
>> > you would consider driving with an NST?  For instance, I hear a lot of
>> > people building 4-inch diameter secondary coils of various heights,
>> > prehaps
>> > even 6-inch diameter or so ... but is there some correlation of
>> > transformer
>> > KVA rating and secondary coil size, or is it really more about how
>> much
>> > bang
>> > you can get out of a primary capacitor?
>> > _______________________________________________
>> > Tesla mailing list
>> > Tesla@xxxxxxxxxxxxxx
>> > http://www.pupman.com/mailman/listinfo/tesla
>> >
>>
>>
>> _______________________________________________
>> Tesla mailing list
>> Tesla@xxxxxxxxxxxxxx
>> http://www.pupman.com/mailman/listinfo/tesla
>>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>


Dr. Resonance

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla