Re: tesla coil operation illustration (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 24 Aug 2007 13:55:49 +0200
From: Kurt Schraner <k.schraner@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: tesla coil operation illustration (fwd)

Hi Scott B., Dr. R, Matt D., Jeff P., ...

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Thu, 23 Aug 2007 18:04:06 -0700
> From: Teslacoil Workshop <workshop@xxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: tesla coil operation illustration (fwd)
>
> Dr. Res beat me to it... I'm a fan of Richie's work too...
>
> Jeff Parisse
> kVA Effects
>
> ----- Original Message -----
>> Richie Burnett's website is the best to understand coils.
>> Dr. Resonance

...I confess to be a total fan of Richie Burnett's work fan as well! 
Specifically the detail-link:

http://www.richieburnett.co.uk/operation.html#operation

should be digested by every coiler, IMHO. I'd also recommend to realize the 
simple coupled double pendulum, mentioned in step 8 of the above site, 
...and contemplating about it. It's a great analogy. And when I try to 
explain TC's to laymen, I'm starting with it. And it can make one starting 
to think about resonance in disruptive TC's. And if resonance effects really 
exceeding transformation ratio, as mentioned in some of your mails. Let's 
make an example, which is not taking extreme conditions: my B&W coil.

secondary n2=813 turns
primary   n1=5.2 turns (at tap)
--> transformation ratio N=n2/n1 = 156
charging voltage of cap = 22kV (16kVrms, without resonant rise; estimated)
--> sec. voltage by N: 22kV*156 = 3.43 MV (!!!)

Well, that's just nonsense, 'cause I'm shure not to exceed ~700kV 
sec-voltage. Why? An energy balance is more appropriate and easy (as is the 
case in many thermodynamic's problems!):

(1/2)C1*V1^2 = (1/2)C2*V2^2 if 100% efficient transfer of the primary energy 
to the secondary.

With C1=165nF; L1=27.5uH --- C2=84pF; L2=53.7mH this leads to around 1MV max 
(using my TCplan), while in practice the 70% efficiency ~680kV value is more 
probable; even optimistic.

So what about resonance in disruptive coils? - In contrast to i.e. DRSSTC's 
or CW coils, we will _not_ observe real resonant voltage rise, higher than 
i.e. the transfomation ratio. But resonance in the loosly coupled 
dual-resonant, well tuned, system, anyway is needed, in order to transfer 
the (almost)whole primary energy to the secondary, in a limited number of 
cycles. The investigation, of how close to 100% the energy transfer can be, 
leads also to the so called "magical values" of the coupling coefficient. 
I'm shure, some of my friends on the list are able to elaborate more and 
better on the missing resonant rise in disruptive TC's ;-)

Cheers,  Kurt