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Re: Coil efficiency


From:	NTesla [SMTP:ntesla-at-ntesla.csd.sc.edu]
Sent:	Tuesday, November 11, 1997 7:53 AM
To:	tesla-at-pupman-dot-com
Subject:	Re: Coil efficiency

At 06:37 AM 11/11/97 -0400, you wrote:
>
>From: 	John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
>Sent: 	Monday, November 10, 1997 3:22 PM
>To: 	Tesla List
>Subject: 	Re: Coil efficiency
>
>At 05:42 AM 11/9/97 +0000, you wrote:
>>
>>From: 	ntesla-at-ntesla.csd.sc.edu[SMTP:ntesla-at-ntesla.csd.sc.edu]
>>Sent: 	Saturday, November 08, 1997 11:09 AM
>>To: 	tesla-at-pupman-dot-com
>>Cc: 	ntesla-at-ntesla.csd.sc.edu
>>Subject: 	Coil efficiency
>>
>
>>I find output spark-length to be meaningless as anything other than a "wow"
>>factor, since spark length is directly related to oscillator-frequency,
>>humidity, atmospheric pressure and air-temperature. 
>
>--------------------------------------------------------------
>
>  Dan -
>
>  The Tesla List has been trying to agree on this problem for some time.

I don't think that's accurate...Rather, the idea has been promoted without
acceptance for some time.

>  What method would you recommend for rating Tesla coils for comparison
>purposes. The method should use readily available devices and be easy for a
>coiler to implement.

Simplistic as it might sound, if I take "efficiency" to mean
"power-processing with minimal loss", I'd look at *loss* instead of
power-processing. However, I'm hardly measurement-oriented ;) If I had
taken spark-length to be a measure of "efficiency", coil-effectiveness, or
whatever, I might have thought that my 1-foot coil with 10-inch output was
"efficient" 10 years ago. ;) Or that my 2-foot, 6-inch dia. coil with
3-foot discharge was "efficient" Yet as I load coils more and more, output
increases more and more...Is my coil more "efficient" with greater and
greater topload? Well, I'm getting more spark, but that tells me nil about
my system or how well it's processing power.
If coil components are running without overheating, i.e., easily processing
the power that is input to them, and I don't include heating effects due to
being overdriven here, then they are running "efficiently", spark-gap
included. 
If I take a coil-system to be the sum of its loss-minimized components,
then the coil is "efficient", all that's left is "tune"

But even if you disagree with all that (It's mostly rhetoric anyway ;), how
can you say that "identical" coils, one operated in a controlled
atmosphere, and the other outside on a cloudy, breezy day are going to
compare in spark-length? And am I, as a beginning coiler say, going to be
frustrated because I can't get the spark-output that "coil-efficiencies"
predict, because I might live in the Andes of Peru instead of Salt-Lake
City, Utah?

If I were really obsessive over the idea of "power-precessing with minimal
loss", I'd build two "identical" *systems* and wire them back to back so
that the output of the secondary of system one became the input to the
secondary of system two. I'd then measure backwards to the power-supply of
system two and see what I was getting out. I'd then reverse the process and
see what I got out of system one. If the systems were "identical",
"power-in vs. power-out" would be a non-complicated, direct measurement.
Tesla received a patent on a lighting/communication system that worked
something like this idea, so it's at least feasible. I don't even think
that atmospheric conditions would affect power-processing too much in the
above scenario, since nothing that's being measured is a relatively
arbitrary dependency, like spark-length. 

Hmmm...if I get the ex to let me into the workshop, I might even try it
myself. Talk about power-processing. *laugh*

Dan