# Re: How should we measure coil efficiency, was neon vs. potenti

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From: 	John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: 	Thursday, July 31, 1997 4:41 PM
To: 	Tesla List
Subject: 	Re: How should we measure coil efficiency, was neon vs.    potenti

At 11:56 PM 7/29/97 +0000, you wrote:
>
>From: 	Wes A Brzozowski[SMTP:wesb-at-blue.spectra-dot-net]
>Sent: 	Tuesday, July 29, 1997 6:05 AM
>To: 	Tesla List
>Subject: 	Re: How should we measure coil efficiency, was neon vs.   potenti

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Wes, All -

The Tesla coil operating frequency appears to have an optimum frequency
because large coils use low frequencies and small coils use high
frequencies. This means a coil could be improved by increasing the operating
freq if it is operating below the optimum and decreasing the freq if it is
operating abuve the optimum.

I have collected operating freqency and input power data from dozens of
actual coils built in the past. The data was normilized and converted into
an equation using regression math. The frequency/power equation is

KWH = 3032.5 x W^-.2767 - 96.4     W = watts input

This equation represents what the typical coiler used for operating freqs
in the past with successful coils. This equation would be a good place to
start our designs today until enough new data can be collected to bring it
up to date.

The primary and secondary tank parameters could then be chosen using the
equation

KHZ = 1/(6.283 sqrt(LC))

It is true that there are many other parameters that affect output,
however, having a place to start is better than pulling a frequency out of
the air for no apparent reason. In this way we will be using the experience
of the old timers!?

This system can be easily tested by designing the coil so it could be
operated at optimun frequency with adjustments for about plus or minus 20%.
The length of the spark could then be used as a measure of performance.

John Couture

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>> Tesla List wrote:
>>
>>
>> >   Where did you find that higher frequency gives shorter sparks?  I believe
>> > it is the other way around.  The higher the frequency the longer the spark.
>> >
>> >    Energy = hf    h = Planck's constant   f = freq.
>> >
>> >    From the above equation the energy increases as the frequency increases,
>> > other factors being equal. This would mean when the frequency increases the
>> > spark length increases.

>     John Couture
>

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