RE: TC Spark Energy

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

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


Dr. Resonance -

The pri cap was .02 uf (see calcs). The NST was a 7500 V, 30 ma operated at
about 5700 x 1.41 = 8000 V peak.

John Couture

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



-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, March 14, 2004 12:51 AM
To: tesla-at-pupman-dot-com
Subject: Re: TC Spark Energy


Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>


John:

What is the value of the capacitance in the pri for these calculations?  I
presume this was an NST powered coil -- what is xmfr sec current, 30 mA or
60 mA?

Dr. Resonance


  > 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.
  >
  >
  >