Re: New Primary Design


If you look in the archives, you can find info about more compact
primaries.  See one example quoted below:

Malcolm stated in part:
>I have finally done a definitive test of 
>a stacked spiral primary and it works extremely well. The something 
>for nothing bit is that if you built the bundle of copper tube I 
>bought into a single flat spiral you might scratch 50uH from it. 
>Arranging it in two layers with a sheet of acrylic in between brought 
>it close to 80uH simply by making use of mutual inductance. The 
>tubing is 3/8". It came as a 2- layer coil that spiralled in on one 
>layer then back out again on the next. If you lifted the outer turn on 
>one side it would form what looked like an hour-glass.

As I recall, there is more info on the double flat spiral primary in the
archives.  It might be the way let you use a primary with a smaller
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: New Primary Design
> Date: Friday, September 10, 1999 5:37 PM
> Original Poster: NickandSim-at-aol-dot-com 
> Hi All,
>          My next coil has just grown from 2.4kVA 8"dia. to 4.8kVA 13"dia.
> Unfortunately I now do not have room for the primary that such a large
coil ( 
> 147cm high 32.5cm diameter) would need using the normal design ruled for 
> small coils.  Darn.  I wondered if any of you with experience in coils of

> this size, Dr. Rez etc., would be able to give me any advice on the
> primary I can get away with, as the rule of secondary length = primary
> does not seem to be so rigorously used on big coils as on little ones. 
> wire is 0.6mm diameter copper magnet wire.
> Also just a note to everyone who came forward with caps for sale and/or 
> advice, thanks guys.  I now have an 8F 10kV cap on its way to me.
> BTW:Thanks to Bob Golding for the xfmr core, boy is that one big limiting

> inductor.
> Sooo this is your second coil............
> Nick Field