From: "Malcolm Watts"
Date: Tue, 24 Oct 2000 09:09:59 +1300
Subject: Re: [TSSP] NSVPI - Latter Results
Hi Terry,
Here is something to ponder:
On 21 Oct 00, at 21:40, Terrell W. Fritz wrote:
> Hi All,
>
> All the data is in, and my new probe seems to be totally successful!!!
>
> Some details...
>
> I found that the windings on my space wound coil are imperfect a bit.
> Some sections had more or less turns than others. The windings
> loosened during a dry spell once and the winder is not perfect. This
> caused a little jumping in the numbers. I was worried that it was the
> probe but the numbers repeat extremely well so I blame the windings
> not being the exact same number in every section.
>
> As seen in the photos, the coil is on a rather quickly made ground
> plane. It is split so as to avoid the shorted turn effect.
>
> I measured the Q of my coil using the Q=Fo/BW formula and based that
> on the measured RMS input current. The Q was 59.25 (146.34 /
> (147.61-145.14)).
>
> With an input voltage of 0.6606 RMS, I would expect the top voltage to
> be: 0.6606 x 1.414 x 59.25 = 55.35 volts.
>
> The sum I measured is 69.72 volts.
Guess what: your sum = 4/PI * 55.35V more-or-less. By an
interesting coincidence, VSWR = 4/PI * Q.
I Haven't looked at the graphs and pictures yet but I'm
guessing there is no topload on that resonator.
Regards,
Malcolm
> Now for the exciting data!
>
> The profile is pictured at:
> http://63.225.104.49/TeslaCoils/Misc/PaulNich/ProfilerPics/TheProfile.
> gif
>
> The excel file is at:
> http://63.225.104.49/TeslaCoils/Misc/PaulNich/ProfilerPics/Profiler.xl
> s
>
> The same data in text format is at:
> http://63.225.104.49/TeslaCoils/Misc/PaulNich/ProfilerPics/ProfileData
> .txt
>
> The picture of the profile in the first link says it all... An exact
> match of what Paul's program predicts!!
>
> Here is the tabular data:
>
> Section Voltage Voltage+Vdiode Summation
> (peak)
> 1 1.48 1.6 1.6
> 2 2 2.12 3.72
> 3 2.38 2.5 6.22
> 4 2.54 2.66 8.88
> 5 2.76 2.88 11.76
> 6 2.7 2.82 14.58
> 7 3 3.12 17.7
> 8 2.8 2.92 20.62
> 9 3.02 3.14 23.76
> 10 2.92 3.04 26.8
> 11 2.88 3 29.8
> 12 2.84 2.96 32.76
> 13 2.8 2.92 35.68
> 14 2.72 2.84 38.52
> 15 2.74 2.86 41.38
> 16 2.66 2.78 44.16
> 17 2.4 2.52 46.68
> 18 2.4 2.52 49.2
> 19 2.3 2.42 51.62
> 20 2.24 2.36 53.98
> 21 2.12 2.24 56.22
> 22 1.98 2.1 58.32
> 23 1.78 1.9 60.22
> 24 1.7 1.82 62.04
> 25 1.64 1.76 63.8
> 26 1.42 1.54 65.34
> 27 1.32 1.44 66.78
> 28 1.06 1.18 67.96
> 29 0.92 1.04 69
> 30 0.6 0.72 69.72
>
> Enough for now...
>
> Cheers,
>
> Terry
>
>
>
>
> Previous post
> ----------------------------------------------------------------------
> ------ -------
>
> Hi All,
>
> Here are the early raw results of the voltage profiling experiment.
>
> One inch sections of the coil were numbered 1,2,...30 with the base
> section being 1.
>
> The secondary was scratched at every inch to gain electrical contact.
>
> The profiler had to be held by a tripod since there was no way it
> could be held by hand. I had to position it, get away for a moment,
> pull the probe out and take the reading.
>
> I tested the probe in the forward and reverse directions and the
> reading were the same.
>
> I retested a single section three times and the reading were extremely
> consistent.
>
> I had to check continuity with a voltmeter when the probe was place to
> insure the delicate contact was made. I then shorted the cap to
> insure it was at zero voltage before the reading. very delicate and
> tedious but fairly tolerable.
>
> The coil was driven by a <1 ohm Z signal generator but a 49.8 ohm
> surface mount resistor was put inline for current sensing. Thus, the
> generator had a 50 ohm impedance.
>
> The frequency was 146.45 kHz. The voltage drop across the resistor was
> 46.5mV ACrms The generator puts out 0.7071 VACrms, or 1 volt peak, or
> 2 volts P-P. It is a MAX038 Chip device. The multimeter is an
> HP34401. The scope is a Tektronix B210.
>
> Reading the voltage of the cap with the fancy digital storage scope
> was child's play. It was consitant and deadly accurate. At these low
> voltages, the cap should have not drifted at all.
>
> From the above, The input voltage was 0.6606 VACrms at 0.9337mA at
> 146.45kHz.
>
> Exciting pictures of the mess can be found at:
>
> http://63.225.104.49/TeslaCoils/Misc/PaulNich/ProfilerPics/
>
> At the moment I have tested sections 22 to 30 and the numbers are as
> follows. Section 30 is the top.
>
> These numbers need the diode drop added still. That number seems to
> be 0.12 volts.
>
> Position Peak Voltage (Vdc)
>
> 30 0.60
> 29 0.92
> 28 1.06
> 27 1.32
> 26 1.42
> 25 1.64
> 24 1.70 1.68 1.68 (Repeated 3 times)
> 23 1.78
> 22 1.98 1.96 (reversed probe)
>
> At this point it was supper time and my knees started to give out. If
> there are any bumps around 27,26,25, those were the very first
> readings and things were "uncontrolled" a bit...
>
> I have only taken the data and typed it up here so I have not really
> looked thoughtfully at the numbers yet. I assume they make sense
> (hope hope). I do note that the steel ruler theory seems to be in
> serious trouble =:o)
>
> I hope to get the rest of the points tonight if the old body can do
> it. All seems to go very well and the readings seem very good but it
> is hard work! This is all minutes fresh so forgive any obvious
> errors.
>
> Comments and suggestions or always welcome.
>
> Cheers,
>
> Terry
>
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.