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Re: Tesla Coil Formula



Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

I updated the Tesla coil formulas today (V3.0) with the peak primary current formula and added CD 940 and 942 specs at the end:

http://hot-streamer.com/temp/FormulasForTeslaCoils.pdf

When thinking on Malcolm Tesla's capacitor stuff, I realized that these would be fine additions to that doc to help give a one stop source for the "basic" info...

I did not add the wire length formula that Jared mentions. IMHO, and in my experiences, and in the opinions of many folks... That is just is not a factor at all for making a good coil... Today, the computers along with the vast studies by those like Medhurst, Nicholson, Wheeler, and M. de Queiroz have sort of left "simple formulas" in the dusts of history...... We used the "best of the breed" data and formulas in our work... The moment one is proven wrong, we just "fix it" it with a better one ;-))) Of course, that document is "open source" so if you can make a better one, just "go for it" :o)))) Here is the OpenOffice source file:

http://hot-streamer.com/temp/FormulasForTeslaCoils.odt

www.openoffice.org

If you can make a better one, we will come ;-))))

Cheers,

        Terry


At 09:42 PM 12/12/2005, you wrote:
Hi Jared,

Frequency will change the inductance. A "change in magnetic flux" forms an induced voltage by means of the change in current. Tesla Coils and their frequency's are affected by changing currents and the varying waveform is only the beginning. Because the coil is, a coil, there are also changes in current due to the shape and geometry of the coil itself. There are many such causes to current opposition as you know. All of these "changes in current" cause various values of induced voltage along the length of the coil. When all is said and done, you will "not" measure the same inductance at high frequency in a coil as you would with a low frequency inductance, or even a high frequency inductance with a different geometry (yet same length of wire). The difference in inductance is not large, but it is often enough to cause a significant change in frequency. When I refer to the interturn inductance, I am referring to the fact that you will measure different values of inductance along a coils length for the same number of turns (or same length of wire). That is a fact.

When I am referring to interturn capacitance, I am referring to the distribution of capacitance for each turn and how each turn adds to the total effective capacitance. As you know, nearby objects also affect the distributed capacitance as does the ground plane, top load objects, etc. I didn't mean to limit C.

I know that high frequency affects are not well understood by all the list members and I don't claim to have great knowledge of every detail. For everyone I know, this is an ongoing study, and in my opinion, nothing is ever written in stone. There are many ways to look at the same thing. As long as there are no gross missing parts, then fine. Most of us started with wire length theory's and applied it to our coils. However, some major pieces to the puzzle were not being accounted for, and we all knew it. The missing pieces were known, just not accounted for. But, that was then.

Take care,
Bart


Tesla list wrote:
Original poster: Jared E Dwarshuis <jdwarshui@xxxxxxxxx>

The length of the wire has no ability to account for the inter-turn
capacitance or inter-turn inductance which is formed by currents
within the wire and currents affected by other currents in adjacent
turns. This is "ridiculously" obvious. If one must consider these
"re..............