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Re: Why does top capacitance work? (fwd)





---------- Forwarded message ----------
Date: Thu, 27 Feb 1997 00:48:41 +0000
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
To: Tesla List <mod1-at-pupman-dot-com>
Subject: Re: Why does top capacitance work? (fwd)

At 05:29 AM 2/26/97 +0000, you wrote:
>
>
>---------- Forwarded message ----------
>Date: Tue, 25 Feb 1997 20:20:30 -0800
>From: Greg Leyh <lod-at-pacbell-dot-net>
>To: Tesla List <mod1-at-pupman-dot-com>
>Subject: Re: Why does top capacitance work? (fwd)
>
>Ed Sonderman wrote,
>> 
>> 
>>  Ed,
>> 
>>  I was curious if you noticed where the extra 3kVA power went when you
>>  increased to 7kVA.  Did something get 3kVA hotter?
>> 
>>  -GL
>>   >>
>> GL,
>> 
>> I measure the power into the system by monitoring the pole pig primary
>> current and voltage.  The only thing I can tell you for sure is the watts
>> consumed.  As to where they went, I am not sure, maybe into the spark gaps?
>>  Maybe it gets reflected back into the primary and is lost as radiated
>> energy?
>> 
>> Ed Sonderman
>
>
>Ed,
>
>At this point, it seems crucial to know _how_ the extra power was applied to
>the coil.  Did you increase the primary voltage (longer sparks), or increase 
>the gap rate (thicker, faster sparks above ~300 PPS) ??
>
>-GL
>
>------------------------------------------------

Ed & GL -

Finding the true wattage input to a Tesla coil is impossible without very
elaborate instrumentation. The power is voltage times current times cosine
of the power factor. The voltage is a rough sine wave but the current is in
pulses of varying waveshapes. The power factor cannot be metered with
standard meters because finding the power factor of pulses is a tricky
problem. All standard AC meters are only for RMS voltages and currents. Non
sinusoidal conditions require special instrumentation.

Adding power to a T.C. (usually by increasing the voltage) and getting very
little increase in spark length would indicate that the extra current you
are seeing is reactive and not doing much good. Also, the spark output of a
Tesla coil is dependent on the energy input minus the losses. If the energy
input is increased but the losses also increase due to higher voltages in
the secondary there will be little increase in spark length. The overall
design of the Tesla coil must be coordinated so losses are a minimum and
spark length a maximum.

The problem with comparing the spark length of a classical Tesla coil vs the
magnifier is in the difficulty of determining the true wattage inputs of the
two systems.

Note that the top capacitance's primary function is to keep the Tesla coil
in tune. It's next in importance function is to store electric charge. The
size of this capacitance should be coordinated with the true wattage input
to the Tesla coil system. Wattage input represents coulombs of electricity
and the top capacitance stores coulombs as a function of capacitance and
voltage.

I would be interested in hearing comments on how the true wattage input
could be metered so we can compare the classical TC with the magnifier.

John Couture