Re: Balancing L/C Sizes

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

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

In a message dated 4/30/01 1:45:49 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes: 



>
> Original poster: "Scott Fulks by way of Terry Fritz <twftesla-at-uswest-dot-net>" < 
> darkthing-at-earthlink-dot-net> 
>
> William wrote: 
> > wire gauge shouldn't make much of a difference, since 
> > you can get twice as many turns with wire that is half 
> > as thick. Since twice as many turns means four times 
> > the inductance, while half as thick wire makes four 
> > times the resistance, the inductance/resistance ratio 
> > stays the same no matter how small your wire is. 
>
> This is not strictly true, due to the "skin effect" at high frequencies.  As 
> the wire gets thicker, only the outer surface conducts the HF current, so 
> for thick wires the resistance increases in inverse proportion to the radius 
> of the wire, rather than the radius squared.  Oddly enough, this means 
> thinner wires are more efficient carriers of current in TC secondaries. 
>
> As an example, at 100 khz, only the outer .2 mm or so of wire conducts 
> effectively, so any wire gauge heavier than 26 (radius of .2 mm) will start 
> to lose efficiency.  The thicker wire has a lower inductance to resistance 
> factor (Q) on a given coil form than the thin wire. 
>
> However, most coilers seem to use the "1000 turns" rule, which makes this 
> argument less relevant.  For a fixed number of turns, the thicker the wire 
> the lower the resistance at any frequency. 
>
> Regards, 
> Scott Fulks (darkthing-at-earthlink-dot-net) 

Hi Scott, All! 

Is High Q really the defintion of operating efficiency in a Tesla coil? 

Matt D.