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Voltage/Length (fwd)
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From: Greg Leyh [SMTP:lod-at-pacbell-dot-net]
Sent: Thursday, February 05, 1998 6:17 AM
To: Tesla List
Subject: Re: Voltage/Length (fwd)
John H. Couture wrote:
> It should be noted that using the equation
> Vs = Vp sqrt(Cp/Cs)
> can give incorrect results when applied to Tesla coils.
[snip]
> If the Cs is reduced in the above equation (reduce toroid size) with no
> other changes the Vs and sparks can be shown to be greatly increased. We
> know this is not true because it is contrary to tests of real coils.
But Vs isn't the the only factor that affects spark length!
Real world factors, such as break rate and terminal capacitance
both _dramatically_ affect spark length, independent of Vs.
When you increase the toroid size and see longer sparks,
Vs has actually _decreased_, but the coils' effectiveness
at propagating the spark channel has improved by an even
greater amount, due to bigger toroid's improved capacity
to provide fast currents to the base of the spark.
The equation Vs = Vp sqrt(Cp/Cs) follows directly from
Conservation of Energy, and simply sets an _upper limit_
for Vs. It's true that Vs can drop below this amount
if the coil is inefficient, but Vs can never be _larger_
than this quantity.
-GL