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Re: Tesla Coil Power Calculations



Hi Terry,

> Original Poster: Terry Fritz <twftesla-at-uswest-dot-net>
> 
> Hi All,
> 
>     I calculated out and listed all the power losses in my LTR coil with the
> latest and best info I have.  It appears the gap is more efficient than I
> thought it was and there is more power to the arc than I thought.
> Surprisingly, the primary and secondary coils appear to be dissipating 70
> watts each.  There is about 23 watts lost to terminal and self capacitance
> ground losses too.  With the PFC cap, the VA into the coil is 860 with a
> bit being lost in the variac with is not taken into account here.

Consider that with a close to 90% reversal in the first primary half 
cycle of oscillation, gap ionization reaches a maximum. As ions don't 
disappear all that quickly, the reducing gap current beyond that is 
causes far less losses than one might think if one assumes that Rgap 
follows primary current. I'm suggesting that Vgap drops to a low in 
the initial 1/4 cycle and pretty much stays there until the end of 
primary ringdown. If this does happen, then as Ip drops, so does Pgap. 

Regards,
Malcolm

>                 Watts   Percent
> Power into coil     840 100
> Power in 50 foot cable      15.88   1.89
> Power in neon primary       30.47   3.63
> Power in neon secondary 38.2    4.55
> Power in NST filter     96.4    11.48
> Power in gap            156 18.57
> Power in primary cap        9.354   1.11  (7.5C temp rise)
> Power in primary coil       76.08   9.06
> Power in secondary coil 71.84   8.55
> Power in self capacitance   14.95   1.78
> Power in terminal capacitance   8.49    1.01
> Power to arc            322.0   38.33
> TOTAL               839.66  99.96
> 
> The "effective" primary circuit resistance (used in MMC calculations) is
> 2.4 ohms.
> 
> Much data to ponder...
> 
> Cheers,
> 
>     Terry
> 
>