Re: Input power measurement

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

Original poster: "David Sharpe by way of Terry Fritz <teslalist-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

Hi Skip

Tesla list wrote:

 > Original poster: "Skip Greiner by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <sgreiner-at-wwnet-dot-com>
 >
 > John and All
 >
 > You are quite correct. There are numerous opinions and many avenues open for
 > experiment. I received a circuit for a solid state watt meter from one of
 > the fellows in TCBOR a while back and I think the first thing I must do is
 > to build it, finally. Of course it would still have to be calibrated
 > somehow.

I gave you the schematic, and I have a PCB designed for it.  140VAC, 15A
no more then 1400W.  Calibration is easy, use a floor heater.  V*I = P and
yes I checked with a NIST traceable Yokogawa WT2010 single phase
100KHz, 16 bit wattmeter, error was <1% across full span.


 > If we are to really evaluate efficiency , we need to find an
 > acceptable ( to all )way to measure the various input parameters. Since most
 > of us modify our transformers in some way, the biggest sparks do not
 > necessarily indicate maximum efficiency. I plan to report to the list
 > anything  I might come up with. Thanks to all for your many comments.
 > Skip

Power Input = Energy * Time
Energy = 1/2CV^2
Time (frequency) = BPS

Therefore

Power Input = 1/2CV^2 * BPS

V to capacitor is based on RMS of firing interval which is
       NOT 0.707*pk based on full cycle but more like 0.91
       of pk value based on firing "window of opportunity"
       of 45 - 135 degrees (half power points on sine wave).
       Tesla discusses this point to some degree in the CSN.

Characterizing input power is a much easier issue then
comparing to spark length, 'E' fields, peak power,"brightness"
of sparks or any other comparative descriptor the list would
want to add.  Monitoring RMS or peak RF currents into base
of secondary coil (resonator) I've done, and might be a way
around the conundrum (Base current to spark length), but
still depends on wire size, inductance, H/D ratio, and other
constructional variables of secondary, and top loading
effects of toroids, spheres, etc. used to load resonator.

Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA

<<SNIP>>