Re: Toroid Modeling

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Mddeming-at-aol-dot-com>

In a message dated 8/29/01 1:15:08 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes: 



>
> This is a model of a 3 x 15 inch coil using 28awg wire (Ls = 14.53mH). The 
> secondary is modeled by itself (1" off the ground). Ceiling height is 108" 
> and wall 
> distance is 72". There is no doubt that with increased toroid size, the 
> wall and 
> ceiling distance do affect the output parameters. However, I don't think 
> this is 
> what is causing the capacitance decrease beyond the free-spaced toroid 
> value. I 
> don't know what's causing it. It may be an E-Tesla6 error (but I doubt it). 
> The 
> pattern repeats itself for any given secondary and toroid configuration. I 
> suspect 
> the removed proximity to the secondary and increased proximity with the 
> ground 
> plane may be the cause. 



It makes sense that as the toroid is enlarged, it will approach the 
free-space value. But then as it is made larger, to where its diameter 
approaches and then exceeds its height above ground, it will recede from the 
free-space value because of the proximity of the ground as H/D for the toroid 
becomes progressively smaller. Good analysis! 
Matt D.