Re: Seibt Photo

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>

 Correction: up to 18% error depending on the conditions

Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Sunday, June 12, 2005 9:49 PM
Subject: Re: Seibt Photo


> Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>
>
>
> Hi Kurt,
>
>
>  > Original poster: Kurt Schraner <k.schraner@xxxxxxxxxxx>
>  >
>
>  > I'm yet wondering, what's wrong about using Medhurst/Lundin (or even
>  > Wheeler) for these coils, as a preliminary design tool...
>  >
>  > Best regards,
>  >                Kurt
>
> I am surprised this question still comes up.
>
> Medurst built his tables to determine the parallel C that had to be added
to
> a much larger parallel C to correctly (<1%) predicted the resonance
> frequency in the usual equation.
> Its is only valid for large parallel C's, isolated, one end earthed coils.
>
> At and near resonance with a lightly top loaded coil, the coil current is
> not constant a long its length which is the conditions that Medhurst
> measured his coils.
> The none constant current leads to significant errors relative to Medurst
> conditions. About 18%.
>
> There are also other errors caused by other none Medhurst conditions like
a
> ground plane and using it in a series. Some of these tend to cancel the
> errors caused by the variable coil current in many usual Tesla coil
> configurations. I suspect in a long coil the dominate error is the none
> constant current hence the error.
> If you want an idea of what frequency your coil will resonate, Medurst
> remains a very convenient way to ESTIMATE it.
>
> Robert (R. A.) Jones
> A1 Accounting, Inc., Fl
> 407 649 6400
>
>