Re: [TCML] 8 inch tesla coil design

[DC Cox <resonance@xxxxxxxxxxxx>]

Your nst will fail to properly charge a larger cap value resulting in a
rat-tat-tat machine gun like sound from the coil.  Unpleasant.

I prefer to go around 90% (10% UNDER) the res value which results in a very
active smooth spark dancing around the toroid.

3:1 is ok, but 4.5:1 allows for more turns and better output potential.
Also, keep the sec coil form dia as large as possible.  With 3 nsts in
parallel I like to use a 10" ID coilform.

Dr,. Resonance




On Thu, Sep 9, 2010 at 9:30 PM, <jeremyee@xxxxxxxx> wrote:

> So the rule of thumb of using only a 3:1 aspect ratio for secondary
> diameters of 8 inches or more is no longer recommended? It has been several
> years since I looked at this. Thanks for the input.
>
> Also, David, I am using an MMC and to up the capacitance I could put
> another string in there. It would raise the capacitance from 30 nF to 45 nF.
> Can an NST handle charging this load or will I get erratic behavior out of
> my static gap?  The LTR recommended for my power supply is about 35 nF.
> Thanks again for the inputs!
>
> Jeremy
> Sent from my BlackBerry device from Cincinnati Bell Wireless
>
> -----Original Message-----
> From: DC Cox <resonance@xxxxxxxxxxxx>
> Sender: tesla-bounces@xxxxxxxxxx
> Date: Thu, 9 Sep 2010 14:22:43
> To: Tesla Coil Mailing List<tesla@xxxxxxxxxx>
> Reply-To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Subject: Re: [TCML] 8 inch tesla coil design
>
> 3.5:1 is ok.  4.5:1 will provide better performance.
>
> I usually shoot for 10-12 turn pri, so you might wish to add a small amount
> of capacitance, but your 14 turn pri should also work very well.
>
> Dr. Resonance
>
>
>
>
> On Wed, Sep 8, 2010 at 7:59 PM, <jeremyee@xxxxxxxx> wrote:
>
> > Hey group. It has been a long time since I have been on here and I wanted
> > to pass a design by you guys to see if I have anything weird. Below are
> some
> > inputs to and outputs from TeslaMap:
> >
> > 15 kV, 120 mA NST bank
> > 30 nF MMC
> > 8.625 inch secondary with 1160 turns of #23 magnet wire (74 mH)
> > 6 in by 30 in toroid (31.6 pF)
> > Tuned primary at 14 turns for 112 uH
> > Resonant at 87 kHz
> >
> > One of my main concerns is sizing the toroid for maximum breakout voltage
> > but keeping the number of primary turns down to minimize resistive
> losses.
> > At 14 turns I feel like I am a little too high. I am using a static gap
> with
> > about 6 parallel copper couplings. My secondary aspect ratio is about
> 3.5:1
> > (is this ok?). I really appreciate any insight into my design. Thanks!
> >
> > Jeremy
> > Cincinnati, OH
> > Sent from my BlackBerry device from Cincinnati Bell Wireless
> > _______________________________________________
> > Tesla mailing list
> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
> >
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla