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Re: TC knowledge



Original poster: "Finn Hammer by way of Terry Fritz <twftesla-at-qwest-dot-net>" <f-hammer-at-post5.tele.dk>

Robert, all!

While it is true that a tesla coil is a transformer, it is not true that
it responds in a turns ratio fasion, when operating in disruptive mode.
Loose coupled coils take time to transfer the energy from one coil to
the other, and the amount of oscillations that it takes to transfer the
energy is determined by the coupling factor. With the coupling factors
that are typically involved in tesla coiling (0.1-0.2) it takes from
8-16 cycles to make a full transfer from primary to secondary.
With regard to top voltage, this is a question of how much energy that
ends up in the toroid.
Let`s say that the primary capacitor is 50nF and that it is charged to
20kV at the time where the sparkgap breaks down and starts conducting.
It then holds a charge of Epri=(Vpri^2)*Cpri/2 =
20000*20000*0.0000005/2=10joule.
When this charge is transferred to the top terminal, the resulting
voltage is:
Vtop=sqrt(2*Epri/Ctop) For a top capacity of, say, 40 Pico Farads the
max. voltage will be:707106 volts.

This is not an impossible value, provided that the secondary coil is
long enough to hold off the voltage, the toroid is smooth enough, and
has a minor diametre large enough to prevent breakout at less than
that,and assuming a lossless gap. (and ignoring coil self capacitance)

Let`s not get carried away with unrealistic claims of multi million
volts on the top terminal, only a few coils exceed 1 million volts.

Cheers, Finn Hammer

Tesla list wrote:
> 
> Original poster: "rheidlebaugh by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>
> 
> A TC is a special transformer. In a transformer when you put a voltage in
> the primary the voltage will be the same out as the ratio of turns. If you
> have 10 turns in the primary and 100 turns in the secondary the output
> voltage will be 10 times larger. Most TC coils have about 1: 100 turns. The
> voltage in is about 20'000v so the output can be 2,000,000V. No this is not
> all, but it is a over view of how it works. My small class room TC starts
> with 100V and puts out 10,000V.
>   Robert  H
>