Re: Primary coil configuration

["Tesla list" <tesla@xxxxxxxxxx>]

Dr. Resonance,

I am building my first coil.  It has a 4" secondary.  Just this 
afternoon I wound a flat primary for it and then read your 
email.  Will a flat primary not work with 4" coils?  I plan on 
powering it with 15KV, 90mA.

[]


Hal in Tucson



----- Original Message -----
From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
Sent: Wednesday, April 19, 2006 4:44 PM
Subject: Re: Primary coil configuration

> Original poster: "D.C. Cox" 
<<mailto:resonance@xxxxxxxxxx>resonance@xxxxxxxxxx>
>
>
> If you run a 4 inch dia. sec coilform use a 15 or 20 degree inverted
> cone primary.  If running a 6 inch dia. sec coilform use a flat
> Archemedian (expanding) spiral.  Overcoupling is a big problem for
> most beginning coil builders and it generates multiple headaches like
> racing sparks, etc.  Keep it simple and it will work right the first time.
>
> Use 1.3 to 1.5 x Cres for your MMC cap value and you will have a nice
> performer.  The 6 inch dia. coil will give you better performance.  V
> = -L x dI/dt.  Inductance, L, is proportional to the square of the
> radius of the coil so bigger is better.  Use #26 AWG for a 6 inch
> coilform and #28 AWG for a 4 inch coilform.
>
> With a reasonably large toroid, ie, 20 x 5 or equiv. modern
> transmission line theory doesn't apply much to TC building.
>
> Dr. Resonance
>
> >Hi All,
> >    I'm in the process of designing my first coil.  I'm a junior in
> > EE and it just caught my intrest while I was researching HV
> > transmission lines. I have a 15kV 60mA NST and I'm reading as much
> > as I can about the rest of the design before I actually 
buy/build anything.
> >    My question is what is the difference between making the primary
> > wind outward away from the secondary opposed to winding vertically
> > keeping the windings all the same distance from the
> > secondary.  Also what does primary placement around the secondary
> > effect.  If I move the primary up to the middle of the secondary
> > what will that effect?
> >
> >~Farmer
>
>
>
>