# Voltage/Length (fwd)

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From:  Greg Leyh [SMTP:lod-at-pacbell-dot-net]
Sent:  Friday, January 23, 1998 6:37 PM
To:  Tesla List
Subject:  Re: Voltage/Length (fwd)

John H. Couture wrote:

> There is no question that the energy in the secondary circuit is less than
> the energy in the primary circuit as I indicated. However, you did not
> address the issue of POWER in the secondary circuit. This power is much
> greater than in the primary circuit. This means that the energy equation you
> used must be modified to reflect power not energy in the secondary circuit.

Why?
There is no law that says power needs to be conserved in
an electrical circuit, so power is a "secondary" issue here.
Only the total system energy needs to be conserved, and I
believe that the energy balance equations given are accurate,
and define the maximum possible voltage for a given coil.

[snip]
>   For your example  100 pf  3 MV  240 bks.
>   The watts (power) in the secondary = 450 x 240 =108 000 Inst watts
>   The efficiency of a coil this size is about 12 percent overall.
>   This requires the equivalent of 900 000 Inst watts in the primary but at
>   RMS conditions.

Actually, energy x BPS gives you the average power consumption
of the coil during operation, in Joules/sec, or Watts.  And
12% efficiency???  This theoretical coil is going to be very
sad, indeed. Don't you think it's possible to do better than 12%?
I'm sure my existing coil does better than 50%, otherwise I
would see more smoke than I normally do.

>   Primary RMS watts for one second = Inst sec watts / TC power gain
>   The JHCTES program shows about 45 000 RMS watts for 3 MV and a 20 ft spark.
[snip]

If you apply that annoying Conservation Of Energy again
to these results, you'll find that the total secondary
capacitance for this theoretical 45kW coil can be no
larger than 42pF! And that's at 100% efficiency! At 12%
efficiency, the Csec must be less than 5pF to get 3MV!

Practically, a coilform that could support 3MV would
have several hundred pF of self capacitance.  And a
higher voltage coil would have yet more capacitance,
hinting at a cubed relationship between thruput power
and output voltage!  This is why alarms go off in my head
every time someone mentions a 'Multi-Megavolt' coil!
Does this bother anyone else?

I don't mean to nitpick here; rather I am trying to
stress that any projections of TC output voltages,
whether arrived at by calculations or by convoluted
measurement techniques, should _always_ satisfy
energy conservation.  Results that don't should be