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RE: Formula for true self capacity of a coil.
Hi John,
If you are asking about the small set of measurements I
took recently, I cannot give a figure for the error. Take them as
being indicative and no more. Isolation was not the best and intrinsic
C measurements could not even be taken (thanks to 70+kW of RF
blasting out from some nearby AM antennas). As I have now said
several times, I will be seeking a large room here in a semester
break when the computers are switched off etc. etc. to get some
*real* measurements. I did this once before about four years ago
and was measuring coil frequencies and Q's approaching 500 with
minimal interference and what I consider to be good accuracy.
Regards,
Malcolm
On 30 May 00, at 13:49, Tesla List wrote:
> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>
>
> Terry, All -
>
> What are the tolorances, etc, of the "actual" measurements?
> It is great that Tesla coil design and testing are finally getting close to
> comparable results.
>
> John C.
>
> ---------------------------
>
> -----Original Message-----
> From: Tesla List [mailto:tesla-at-pupman-dot-com]
> Sent: Monday, May 29, 2000 4:20 PM
> To: tesla-at-pupman-dot-com
> Subject: RE: Formula for true self capacity of a coil.
>
>
> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
>
> Hi John, All,
>
> Let's not loose sight of the "actual" measurements!
>
> 1. 394.5 kHz
> 2. 269 kHz
> 3. 212.7 kHz
>
> I ran these through E-Tesla5 and got:
>
> 1. 412.5
> 2. 286.1
> 3. 201.8
>
> and Cmed got:
>
> 1. 401.43
> 2. 298
> 3. 230.41
>
> and Jones/Cox got:
>
> 1. 397.07
> 2. 296.678
> 3. 208.78
>
> and John C. got:
>
> 1. 403.6
> 2. 299.58
> 3. 231.38
>
> "We" all came out high on the second one compared to the actual... Dare I
> suggest that the second actual could be a little wrong! =:O
>
> It would be a scarry day when we trust the calculations over the actual
> measurements but... In my own testing I kept getting high numbers in one
> test. I went back and check the "actual" dimensions and... oops! The darn
> computer WAS right! ;-))
>
> It "slightly" seems that Jones/Cox is getting the best answers... Of
> course, slap dual toroids on these coils, and I'll vote for E-Tesla5 ;-)))
>
> Hey! Does anyone remember the "good ol' days" when we had no clue what a
> given secondary system frequency would turn out as ;-))
>
> Cheers,
>
> Terry
>
> BTW - Great work Gavin in finding that true C formula!!
>
>
>
> At 03:35 PM 5/29/00 -0700, you wrote:
> >
> >Gavin -
> >
> >You may be interested in how your calcs compare with the JHCTES Ver 3.1
> >program.
> >
> >Coil Parameter Gavin JHCTES
> >
> ># 1 L 17.87 17.87
> > Cmed 8.8 8.9
> > fr kHz 401.43 403.6
> >
> ># 2 L 29.3 28.82
> > Cmed 9.9 9.79
> > fr kHz 298.00 299.58
> >
> ># 3 L 42.25 42.67
> > Cmed 11.19 11.09
> > fr kHz 230.41 231.38
> >
> >Very good agreement considering different equations were used.
> >
> >John H. Couture
> >
> >----------------------
> >
> >-----Original Message-----
> >From: Tesla List [mailto:tesla-at-pupman-dot-com]
> >Sent: Monday, May 29, 2000 11:27 AM
> >To: tesla-at-pupman-dot-com
> >Subject: Formula for true self capacity of a coil.
> >
> >
> >Original Poster: "Gavin Dingley" <gavin.dingley-at-astra.ukf-dot-net>
> >
> snip....
>
>
>