Re: bang power ? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 28 Sep 2007 23:38:49 -0500
From: Bert Hickman <bert.hickman@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: bang power ? (fwd)

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Fri, 28 Sep 2007 11:50:11 EDT
> From: FIFTYGUY@xxxxxxx
> To: tesla@xxxxxxxxxx
> Subject: Re: bang power ? (fwd)
> 
>  
>  
> In a message dated 9/27/07 7:01:48 P.M. Eastern Daylight Time,  Bert  Hickman 
> <bert.hickman@xxxxxxxxxx>
> writes:
> 
>> But, if you reduce the primary inductance (say, by changing the tap  
> 
>> point) this also alters the P-S coupling unless you ALSO change the  
> 
>> primary-secondary geometric relationship. And, as we discussed  earlier, 
> 
>> changing the coupling alters the "ring-up" time (the time to  complete a 
> 
>> single P->S or S->P energy  transfer).
> 
> 
>     In Dr. Mark Rzeszotarski's Tesla Coil Frequently  Asked Questions 
> ("Chapter 7: The Primary Coil", Father Tom McGahee's Q&A  section, pg 37) :
>  
>     "Since k=M/sqrt(Lp/Ls) ... What is not so obvious  is the fact that M is 
> proportional to Np times Ns for most coil geometries we  use in a tesla [sic] 
> coil (solenoid, flat pancake, inverted cone, for five or  more turns in the 
> primary). As a result, by keeping the same geometry and only  varying the number 
> of turns, K remains constant since as Lp and Ls vary, so  too does M." 
>  
>     Didn't Dr.Rzeszotarski develop the "MandK"  program?
>  
> -Phil LaBudde 

Hi Phil,

Yes, Dr. Mark did indeed create the MandK program - a LONG time ago... :^)

The example provided in the above FAQ used an example where the inner 
and outer diameter of two different primaries were the same, but one 
primary had 5 turns, while the other had 10. Since both the inner and 
outer diameters were the same and only the number of primary turns 
changed, "k" remained the same when using a common secondary diameter 
and length. Since the overall primary and secondary geometric 
relationship stays the same (only the number of primary or secondary 
turns change), "k" stays constant.

In the example I provided for Chris, I assumed that we used the same 
primary before and after (i.e., "all other things remain the same" 
except for doubling Cp). However, the primary tap location needed to 
change in order to halve Lp so that we could bring the system back into 
tune. But changing the primary tap has the effect of changing the 
primary's effective outer diameter. Since this changes the geometric 
relationship between primary and secondary, we do, in fact, alter "k".

Bert
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