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Re: neon vs. potential transformer
From: John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: Saturday, July 19, 1997 10:44 PM
To: Tesla List
Subject: Re: neon vs. potential transformer
At 01:26 PM 7/13/97 +0000, you wrote:
>
>From: FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
>Sent: Saturday, July 12, 1997 3:21 AM
>To: tesla-at-pupman-dot-com
>Subject: neon vs. potential transformer
>
> All,
>
> Previously, I built a small TC using a 12 kV, 30ma neon trans, which
> produced a 42" spark using 740 watts as measured with a wattmeter.
> Then for comparison purposes, I replaced the neon trans with a
> potential trans and a suitable ballast, the TC drew about 680 watts
> and gave the same spark length. Toroid size is 5" x 20".
>
> I also had tried using a 15 kV, 60ma neon trans, which gave a 65"
> spark and drew 2600 watts. Yesterday, I installed the potential
> trans into the same TC and with 6.7millihenries of ballasting, it
> produced a 65" spark and drew 2100 watts. Toroid size is 6" x 26".
>
> An 8 point series rotary sync-gap was used in all the above tests.
> The potential transformer is rated at 14.4 kV, 1.5kVA. Input power
> was measured before it entered the main variac. It is
> not known exactly how waveform distortion variations might be
> affecting the input power measurements. (Gotta build the "Dave
> Sharpe" opto-wattmeter).
>
> Spark length measurements over 65" length are difficult because
> the room limits the sparks. The spark hits the 65" point with a strong
> "zap" and could undoubtedly go further. I plan to do more tests and
> will try to improve the efficiency.
>
> These results seem to show that when I increased the input power by
> about 3 times (TCs optimized for the input power--"very" important),
> the spark length increased by about 1.73 times. This follows the direct
> square law, (more in another post).
>
> The lower losses in the potential transformer seem to improve the
> efficiency of the TC.
>
> John Freau
>
--------------------------------------------
John F.
How long were you able to run the 15 KV 60 ma neon at 2600 watts? This is
almost 3 times it's wattage rating. I would expect it to overheat.
You mention efficiency often. How do you calculate this parameter? I am
trying to set up a standard for the efficiency of a Tesla coil. Do you have
any comments?
Compared to just a few years ago the average coiler today knows a lot more
about Tesla coils operation than they did in the past. I believe it is time
to set up some standards of testing them so the test conclusions arrived at
make sense.
Have you checked out this site?
http://www.capital-dot-net/users/ssilver/tesla.html
John Couture