Re: HF sparks
From: Peter Electric[SMTP:elekessy-at-macquarie.matra-dot-com.au]
Reply To: elekessy-at-macquarie.matra-dot-com.au
Sent: Friday, August 08, 1997 5:56 AM
To: Tesla List
Subject: Re: HF sparks
> Peter E.
> The JHCTES computer program shows 331 KHZ for your coil. This is found
> from the pri and sec LC circuits. These two circuits must be in tune and
> give equal frequencies. The program shows 8.9 sec inductance and 25.93 pf
> sec capacitance. What does the WinTesla program show?
The Wintesla shows 315Khz, 9.88mH, 25.76pF. It gives me 8.11pf for the
Sec. coil alone.
> With the 22 inch sphere the frequency should be about 274 KHZ. You
> indicate a capacity of 30 pf, however, the capacity will depend on the
> proximity to the coil, etc which lowers the sphere capacity and increases
> the frequency. The test frequency could be higher than 274.
So much for theory, actual results using the good old two LED and sig
generator method give the following results -
With the above toroid .. 355Khz
With the 22" sphere .. 268Khz
Unloaded .. 619Khz
> Changing the toroid or coil to something larger may increase the spark
> length up to the maximum capability of the power source. Note that optimum
> parameters for spark length vs power, frequency, Q factor, K factor etc,etc.
> are now found by trial and error. Computer programs eliminate some of the
> guesswork. Improvements will depend on how well coilers test their programs
> in the future to get new accurate data. There are few coilers who do much
> testing that produces tabular data and graphs upon which to base design
Being a technical rather than theoretical guy, I am somewhat impressed
by how close most of these programs have come to predicting these values
and particularly the number of turns of primary. (almost spot on with
> Many people on the T. List misinterpreted my reference to increasing the
> frequency as increasing the spark length. I was thinking of sine waves and
> energy. Normally we think of the frequency reducing to DC. However, if you
> have an oscilloscope and sine wave generator it becomes obvious that as you
> lower the frequency the amplitude of the sine wave takes longer to rise
> and would eventually approach zero and zero energy at an infinitely low
> frequency. Increasing the frequency would represent an increase in energy.
> Reducing the frequency of a sine wave does not go eventually into DC but to
> zero amplitude and energy.
> John Couture