RE: Balancing L/C Sizes

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi Terry,
          I suppose I count as "anyone":

On 29 Apr 01, at 15:58, Tesla list wrote:

> Original poster: "terry oxandale by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <toxandale-at-cei-dot-net>
> 
> A very same question I have pondered myself. Anyone??????
> 
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Sunday, April 29, 2001 1:34 PM
> To: tesla-at-pupman-dot-com
> Subject: Balancing L/C Sizes
> 
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
> <Mddeming-at-aol-dot-com>
> 
>  Hi All!
>         A short while ago, there was a very good explanation of LC
> oscillation posted using the analogy of pouring water from one
> container (electrical field in capacitor) to another container
> (magnetic field in coil) and back again. It was mentioned that you
> would, of course, not want to use a bucket and a thimble. This started
> me thinking (danger, danger) that just as there is an appropriate size
> capacitor to store a given amount of energy, 0.5CV^2, there should
> also be an appropriate size coil such that the field of the coil could
> absorb the energy being transferred to it from the cap, so as not to
> empty the "bucket" into the "thimble".

I'm not sure this analogy is the best preferring as I do, the two 
swings on a rope analogy. You might think of trying to dump 10J into 
a secondary that is just few inches high - it will of course flash 
over its windings. As far as the primary cap goes, you can load an 
identical amount of energy into any capacitance provided it has the 
voltage rating. Generally, you'd choose the primary capacitance 
according to the available transformer. The secondary must be tall 
enough to withstand whatever voltage it ends up with when the primary 
cap energy is transferred to it.

 While the primary coil is more
> of a transfer device, (funnel) than bucket, it seems that there must
> be some sort of min/Max size constraint, but I can't recall any
> discussion of an energy storage equation for a coil.

Without getting into a discusion of distribuited circuits you can 
usefully use 0.5*C*V^2 = 0.5*L*I^2 as a working approximation to 
describe equivalences between energy stored in an electric field 
(capacitance) and energy stored in a magnetic field (inductance).

 Likewise, the
> secondary can be looked at as a device to "funnel" charge into the
> topload and ultimately to the streamers. It seems to me that there
> should be some sort of calculable optimal range of sizes out of the
> infinite combinations of L & C for any frequency. It is somewhat
> hinted at in the "rules of thumb" about power, coil size, and topload
> size, but I can't seem to find anything definitive. Perhaps some of
> the theoreticians could elucidate, or a historian could point me to a
> thread I missed?
> 
> Seeking light and lightning in the hills,
> 
> Matt D.

Is that any help?

Malcolm