Re: Wire Length (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Gerry Reynolds <greynolds@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Wed, 20 Dec 2006 08:14:16 GMT
From: Paul Nicholson <paul@xxxxxxxxxxxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Re: Wire Length (fwd)

Bart wrote:

> A spacewound secondary like this hasn't been 
> measured yet that I'm aware of.

True, we have no HF measurements for flat spirals.

Although I think that Ldc of quite a few flat spiral primary
coils has been measured!  Increased turns density of the
secondary should only increase the accuracy of predicted
inductances.

The flat spiral is interesting because currents circulating
through the coil's internal self capacitance serve to increase
the effective inductance at resonance (in a solenoid of typical
TC h/d ratio, Les is less than Ldc).  

> Javatc came up with .004165 H in a linear distribution and
> .004849 H at resonance

The value of Les will depend on whether you choose the center
or the rim to be at ground potential.

Would be very nice to have some Fres measurements of this
coil for the first few modes in both grounded rim and grounded
center configurations.

--
Paul Nicholson
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