Re: TC Spark Energy

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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.
 >
 >
 >