RE: Tesla Coil Operation / NST loading-C spreadsheet

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

Original poster: "John H. Couture by way of Terry Fritz <teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Ed -

I think the best way to show the VA and power relations is to draw two right
angle triangles showing VA,RVA and Watts for both the NST input and output.

For an example to show the input and output power conditions of these
complex (RCL) types of loads draw two right angle triangles, one for the
input and one for the output. Both triangles using the same X axis. The
input triangle with an angle of 25 degrees (90% PF). The output triangle
with an angle of 70 degrees (45% PF).

Measure three inches for the input X axis and 2.5 inches for the output X
axis. The .5 inch difference represents the extra losses at the input. Draw
Y axis lines from the X axis at the 2.5 point and at the 3 inch point. These
lines represent the reactive power of the output and input shown as RVA
(VAR). The output RVA includes the leakage reactance of the NST when
converted to RVA. This will show up in your test measurements.

Take a compass and draw an arc from the zero point on the X axis using a
radius equal to the hypotenuse of the input triangle. Extend this arc so it
intersects both the input Y axis and the output Y axis. The point where the
arc intersects the output Y axis gives you the output RVA where the output
VA equals the input VA.

Any output RVA greater than the above output RVA will give you a power
output (VA) greater than the power input (VA). You can do this by a proper
load combination of capacitors in series with resistors.

Use the standard equations to convert your test results into scale values
for two trangles similar to the above. With several HV capacitors in series
with power resistors you will be able to make several types of graphs
comparing VAin/VAout, Input/Output volts, sec volts/various loads, etc, etc.
There are a lot of possibilities and very little of this type of information
is presently available.

John Couture

------------------------------

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, February 21, 2003 12:53 AM
To: tesla-at-pupman-dot-com
Subject: Re: Tesla Coil Operation / NST loading-C spreadsheet


Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>

Tesla list wrote:
  >
  > Original poster: "John H. Couture by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
  >
  > Hi Kurt -
  >
  > I agree that with a Tesla coil the output power can be greater than the
  > input power. This can be easily shown by drawing a right angle triangle
for
  > the three types of power as I show on my web site.
  >
  > I would also point out that Terry's previous NST test was with a
capacitor
  > in parallel with the resistor load and not for a capacitor in series with
  > the resistor load. I am hoping that Terry will find the time to make the
cap
  > in series with resistor tests as he had planned.
  >
  >   Apparently I am the only coiler who has ever made this type of test
(!?)
  > and posted the graph on the List. The cap\series resistor test gives some
  > very interesting information on the operation of NSTs with RC loading.
  >
  > How has your Excel program worked with the cap in series with resistor
load
  > on NSTs?
  >
  > John Couture

	How about a little more explanation of what you mean?  Define power and
volt amperes in the sense you are using them.  Are you referring your
voltage to the transformer out or the output terminals which have a very
large effective leakage inductance in series with the "transformer"?

Ed