Re: Mutual Inductance & K Factor

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi John, 

Tesla list wrote: 

>
> Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <couturejh-at-mgte-dot-com> 
>
> Bart - 
>
> For rough measurements I recommend the Wavetex (27XT?) or similar meter. 
> This meter measures capacitance, inductance, and frequency in addition to 
> the usual DMM ranges. It will do all the necessary metering for the mutual 
> inductance (Lm) and the K Factor (K).




Funny you should mention that. I have the 27XT. Use it all the time these days.
It's capacitance ability is lacking, but everything else is tops! Between my
Fluke, Wavetek, and Metex (which is excellent in the Frequency arena if nothing
else), I'm set up pretty well in this type of minor equipment. 

>
> I downloaded the Nolan data from your program. This download ability is a 
> nice feature of your program. In the Java outputs I note that the Pri/Sec 
> clearance is one inch instead of the 1.4 inch that I understand is what 
> Nolan said.




No, it's 1 inch. Here are Nolan's original specs (see primary): 

Secondary:  2.375 in diameter by 15in high wound with Awg 28 12.75 in long 
  10 or more coats of polyurethane 
  Primary: 6awg ground wire 0.25in spaced between turns max turn 8.75 1in 
  spaced from secondary 
  Topload: Toroid length is 9.5in and 3.375 cord, made from flexible Al tubing 
  wrapped 3 times in Al tape 
  Cap: Maxwell pulse discharge 0.03uf rated at 35kv 
  Spark gap:  single static gap .25in carriage bolts set at 0.15in just below 
  transformers max spark length 
  Power Supply: Franceformer 7500kv at 60ma 
  

John, the your numbers below won't apply as it's based on an incorrect
parameter. I do agree that only testing verifies prediction, but to that
degree, the measurement technique and accuracy must be looked at carefully.
There are times when the error in measurement exceeds a programs error (both
electrically and physically). 

Take care, 
Bart 

>
> This means the Java K is even lower than previously shown. I 
> believe this Java K is too low for the geometry of this coil while the 
> JHCTES K may be too high. Only testing the coil can solve the problem. 
>
> With Java primary inner diameter = 5.18 the Pri/Sec clearance is 1.4 inches. 
> The new outputs are: 
>
>    Sec above Pri = 0 inches 
>                  Java         JHCTES 
>        Lm       13.53         25.52 
>        K        .1023         .193 
>
> Sec above Pri = 3 inches 
>                  Java          JHCTES 
>        Lm         2.79         10.84 
>        K         .0211         .082 
>
> John Couture 
>
> ----------------------------- 
>
> -----Original Message----- 
> From: Tesla list [<mailto:tesla-at-pupman-dot-com>mailto:tesla-at-pupman-dot-com] 
> Sent: Sunday, March 17, 2002 6:50 PM 
> To: tesla-at-pupman-dot-com 
> Subject: Re: Mutual Inductance & K Factor 
>
> Original poster: "Barton B. Anderson by way of Terry Fritz 
> <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net> 
>
> John - 
>
> Tesla list wrote: 
> > 
> > Original poster: "John H. Couture by way of Terry Fritz 
> <twftesla-at-qwest-dot-net>" 
> > <couturejh-at-mgte-dot-com> 
> > 
> > One thing that would help is for coilers to agree on the kind of tests to 
> be 
> > made. This would help to solve some of the many unknowns of the classical 
> > Tesla coil including the optimum coupling. 
>
> True. But we can't have coilers go out and buy scopes simply to gather data. 
> Most coilers have at least a multimeter with volt and amp capability making 
> this type of test acheivable. 
>
> I use 2 meters side by side for concentric readings. All that is needed from 
> that point are accurate measurements of the coils. 
>
> ----------------- snip 
>
> Take care, 
> Bart