RE: TC Spark Energy

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

Original poster: "John H. Couture" <couturejh-at-mgte-dot-com> 


Steve -

Trying to find the true energy in a TC spark or streamer may be impossible
without having to make estimates for some of the parameters. Because there
is such a wealth of information on the other characteristics of the spark or
streamer it is possible to make a reasonable estimate of the spark energy.
Below is shown how I found the energies in the major sections of a small TC
that I built and tested. The OLTCs are similar to classical TCs but the
voltages are too low for good comparisons.

Just finding the joules per spark is not enough. To verify your numbers the
coiler should find the energies at each major section in the TC system. This
will guarantee that you do not end up with impossible energy conditions in
some parts of the TC system. This has been a problem with some past
calculations. The energies that are shown could not be possible with the
components used.

Because of the speculative nature of doing a complete analysis of the TC
energies the following has probably never been done by a coiler before.
However, this can be a method of rating TCs for overall efficiency in the
future. This method can be used with any size TC, sparks per second, input
watts, etc.

For example I built and tested a small TC and calculated the energies as
follows.
There were an estimated 120 continuous sparks per second. The spark length
from the toroid to a ground point was 8.5 inches. Operating frequency was
460000 HZ. Coupling was 0.18 between the pri and sec coils. Secondary
current was 300 ma. The variac was adjusted to give 120 watts on the
wattmeter and to give a continuous equal length spark operation as in
standard TC operation. I tried to avoid any random operation or length of
the sparks to get a stable load output.

1. Input energy = Wattmeter reading x time = 120 joules each second.
2. Energy in Primary Capacitor per second = 76.80 joules
3. Energy in Secondary circuit per second = 71.13 joules
4. Energy in 120 sparks per second = 63.27 joules
5. Overall TC efficiency = 52.73%

The calculations are as follows.

  Input energy = 120 watts x 1 second = 120 joules
  Energy per spark = Joules/sparks per second = 120/120 = 1 joule per spark
  Energy in pri cap = .5 CV^2 = (.5)(.02x10^-6)(8000^2) .64 joules
  Total pri cap energy per second = .64 x 120 = 76.80 joules
  Energy in sec circuit = (.5)(14x10^-12)(291000^2) = 0.592 joules per spark
  Tot sec circuit energy per second = 0.592 x 120 = 71.13 joules
  Voltage in spark = 65 x inches^0.7 = (65)(8.5^0.7) = 291 KV (from TCCG
Graph)
  Spark time = 1/(2kF) = (1/(2 x 0.18 x 460000) = 6.04x10-6 seconds
  Energy in spark = V x I x t = (291000)(.300)(6.04x10^-6)
                  = 0.527 joules per spark
  Tot spark energy per second = 0.527 x 120 = 63.27 joules.
  Overall efficiency = energy out/energy in = 63.27/120
           O.A. Eff. = .5273 or 52.73%

Note that many of the parameters above can be verified by proper tests. This
method can be used to rate TCs of any size or wattage. How far have other
coilers gone along using this energy route? Comments?

John Couture

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


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, March 11, 2004 1:22 PM
To: tesla-at-pupman-dot-com
Subject: RE: TC Spark Energy


Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>

  >How did you measure the 2 joules input? Did you use a wattmeter at the
  >input? How many watts did it show? Refer to my reply to Dr. Resonance.

Hi John

I inferred the input energy from the initial voltage on the tank capacitor.
In the case of the OLTCs this is low enough to measure easily with a
peak-hold meter or oscilloscope.

On my spark gap coil, I set the static gap to break down at a known voltage.
This is obviously a bit less accurate than measuring the voltage directly.

The best way to deliver a known energy with spark gap coils would be to
charge the tank capacitor off a regulated HVDC supply, and use a triggered
gap. But this is pretty complex and expensive. Anyway, I think OLTCs are
similar enough to sparkgap coils that findings from OLTCs will be directly
applicable.

Steve C.