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Re: Mutual Inductance & K Factor
Original poster: "Barton B. Anderson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>
Hi John, (fixed width font needed)
Those graphs at my site were run quite a while ago. I should run the numbers
again and update because there have been many rev changes since.
For now, I pulled up Kurt's excel file and ran the numbers fresh. I've thrown
Acmi, JavaTC, MandK, and Kurt's actual measured values in tables below.
Note, the position in the old graphs and in Kurt's file does not indicated a
measurement (inches), but rather a set of parameters for each case. Could just
as easy be position a, b, c, etc.
I used Kurt's measurements at 0", 3.937", and -3.937". Note, for JavaTC the ~4"
heights are moving beyond it's capability, but the 0 it is of course fine.
When looking through this, keep an eye on Acmi and MandK (how close they are to
one another, and to measurement). Categories are Lm, K, and Lp (thought it
would be good to show Lp here): Each run is by turns as measured by Kurt.
Measurement column is actual meter measurements except K of course.
Height = 0" Turns Meas JavaTC Acmi MandK
Lm(uH) 1 37.14 35.83 35.87 36.07
K 1 0.1047 0.1410 0.1244 0.1244
Lp(uH) 1 2.31 1.19 1.51 1.54
Lm(uH) 2 74.83 71.59 71.69 72.09
K 2 0.1352 0.1447 0.1375 0.1380
Lp(uH) 2 5.62 4.52 4.96 5.01
Lm(uH) 3 111.78 107.31 107.45 108.04
K 3 0.1482 0.1476 0.1441 0.1448
Lp(uH) 3 10.45 9.75 10.14 10.23
Lm(uH) 5 186.11 178.54 178.77 179.74
K 5 0.1570 0.1516 0.1512 0.1528
Lp(uH) 5 25.8 25.58 25.49 25.41
Lm(uH) 7.2 264.2 256.58 256.88 257.76
K 7.2 0.1575 0.1541 0.1545 0.1546
Lp(uH) 7.2 51.68 51.16 50.39 51.06
Lm(uH) 9 333.16 320.17 320.5 322.2
K 9 0.1619 0.1550 0.1559 0.1557
Lp(uH) 9 77.79 78.68 77.03 78.62
Now, height = 3.397" (pri above sec):
Turns Meas JavaTC Acmi MandK
Lm(uH) 1 51.86 43.44 52.29 52.43
K 1 0.1462 0.1710 0.1814 0.1808
Lp(uH) 1 2.31 1.19 1.51 1.54
Lm(uH) 2 102.71 86.82 103.11 103.44
K 2 0.1856 0.1755 0.1977 0.1980
Lp(uH) 2 5.62 4.52 4.96 5.01
Lm(uH) 3 151.09 130.12 152.66 153.19
K 3 0.2004 0.1790 0.2047 0.2053
Lp(uH) 3 10.45 9.75 10.14 10.23
Lm(uH) 5 247.22 216.5 248.55 249.55
K 5 0.2086 0.1839 0.2102 0.2121
Lp(uH) 5 25.8 25.58 25.49 25.41
Lm(uH) 7.2 344.84 311.14 350.06 350.92
K 7.2 0.2055 0.1868 0.2105 0.2104
Lp(uH) 7.2 51.68 51.16 50.39 51.06
Lm(uH) 9 431.84 388.25 430.63 432.57
K 9 0.2098 0.1880 0.2095 0.2090
Lp(uH) 9 77.79 78.68 77.03 78.62
You can see how close Acmi and MandK are to one another, how far JavaTC goes
off with this 4" height, and how they compare to Kurt's measured. This should
give a pretty good indication how well MandK and Acmi do against real world
measurements (even a coil of this size) and why programs like JavaTC are good
for approximation (improvement needed, but a good start).
Now, height = -3.397" (pri below sec):
Turns Meas JavaTC Acmi MandK
Lm(uH) 1 21.22 27.97 19.45 19.7
K 1 0.0598 0.1101 0.0675 0.0679
Lp(uH) 1 2.31 1.19 1.51 1.54
Lm(uH) 2 43.29 55.89 40.26 40.71
K 2 0.0782 0.1130 0.0772 0.0779
Lp(uH) 2 5.62 4.52 4.96 5.01
Lm(uH) 3 66.38 83.77 62.21 62.84
K 3 0.0880 0.1152 0.0834 0.0842
Lp(uH) 3 10.45 9.75 10.14 10.23
Lm(uH) 5 116.29 139.38 108.94 109.86
K 5 0.0981 0.1184 0.0921 0.0934
Lp(uH) 5 25.8 25.58 25.49 25.41
Lm(uH) 7.2 169.34 200.31 163.63 164.51
K 7.2 0.1009 0.1203 0.0984 0.0987
Lp(uH) 7.2 51.68 51.16 50.39 51.06
Lm(uH) 9 221.54 249.96 210.28 211.71
K 9 0.1076 0.1210 0.1023 0.1023
Lp(uH) 9 77.79 78.68 77.03 78.62
You brought up something of interest in a separate post involving frequency
affects. I can't comment on loaded coils because I haven't measured this. It
would be good to do this both at line Fr as well as high frequency near the
coils loaded Fres to see if differences pop up (including your Freq measurement
method). Maybe someone has already made a similar check on loaded coils or high
frequency measurements?
John, I put Kurt's coil as -kurt1- in JavaTC. You should be able to pull it up
now (refresh the browser if it doesn't work the first time - this will show you
my inputs - pay attention to OD for each turn of Kurt's coil - this is an
all-important parameter if you model in JHCTES).
Take care,
Bart
Tesla list wrote:
>
> Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <couturejh-at-mgte-dot-com>
>
> Kurt -
>
> Thank you for the graphs. Unfortunately my computer did not print them
> clearly enough to read them. However, I did see that the K Factors leveled
> off flat with no gradual rise. Not sure what that means. Thank you, also,
> for the info you sent me on your coil in the past. I finally found it on my
> computer. Your information has helped me very much in the past.
>
> In Bart's graphs I noticed the K Factors are marked "measured". Does that
> mean you used the frequency test for the K? I have used this test and found
> it to be better than the inductance test for K.
>
> I agree the Mandk and Acmi tests are at present probably more accurate than
> the JHCTES for the K Factor. However, much more test data is required to
> determine the true accuracy of the programs. The JHCTES can be easily
> changed to agree with new test data.
>
> The JHCTES type programs have one very important feature that the Mandk and
> Acmi programs do not have. When the Primary capacitor or Secondary top load
> is changed the mutual inductance changes but the K Factor does not change.
> The Mandk and Acmi programs can not show this because they do not use and
> coordinate enough TC parameters. This unique K Factor behavior was not known
> by coilers until I posted this information a couple years ago on the List.
> Even today you need the JHCTES or Java programs to check this out. Only an
> advanced coiler can explain this interesting fact about Tesla coils.
>
> John Couture
>
> -------------------------------------
>
> -----Original Message-----
> From: Tesla list [<mailto:tesla-at-pupman-dot-com>mailto:tesla-at-pupman-dot-com]
> Sent: Tuesday, March 26, 2002 6:53 AM
> To: tesla-at-pupman-dot-com
> Subject: Re: Mutual Inductance & K Factor
>
> Original poster: "Kurt Schraner by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <k.schraner-at-datacomm.ch>
>
> Hi John,
>
> extensive K factor tests and comparison to Mark's M&K program were
> perfomed in autumn 2000. The simple mutual inductance method (-at- 50Hz
> AC line f) was used for the tests. Some results-graphs can be viewed
> on my website:
>
>
> <http://home.datacomm.ch/k.schraner/bw_mk2.gif>http://home.datacomm.ch/k.s
> chraner/bw_mk2.gif
>
> <http://home.datacomm.ch/k.schraner/bw_mk3.gif>http://home.datacomm.ch/k.s
> chraner/bw_mk3.gif
>
> If they were not deleted, you might find the Excel files, which I have
> sent you, for the full data:
>
> Tue, 21 Nov 2000 05:13:43 File: bw_mk.zip <-- Excel: M&K data
> Thu, 23 Nov 2000 10:11:08 File: BW_design.zip <-- Excel: coil data
>
> The bw_mk.zip file can also be downloaded:
>
> <http://home.datacomm.ch/k.schraner/bw_mk.zip>http://home.datacomm.ch/k.sc
> hraner/bw_mk.zip
>
> The comparison of my- and many others's results with acmi can be had
> on Bart's website:
>
<http://www.classictesla-dot-com/sim/k.html>http://www.classictesla-dot-com/sim/k.html
>
>
> The comparisons are giving a lot of trust in the 2 programs (MandK and
> acmi), and if good precision conditions for the experiment are not
> guaranteed, I would trust more to those calculations, which are based
> on sound physical principles, than to an average-quality experimental
> value. It seems to me, those programs need well to be distinguished,
> from empirical function-fitting formulae (to a limited range of
> experimental data), as a means of prediction: the former beeing
> intrinsically more reliable. They may serve, delivering a set of
> pseudo-experimental data for the fit of an empirical function, the
> way, Bart has provided in his great Java TC calculator.
>
> Cheers,
> Kurt Schraner
>
> Tesla list wrote:
> >
> > Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> >
> > Bart -
> >
> > Just finished checking the K factors for Kurt Schraner's BW coil of
> > 11/24/01.
> > Pos = Secondary above Primary in inches.
> > Mark = Mark Rzeszotarski's MandKver31 program. Thank you Mark.
> >
> > Pos Mark Java JHCTES
> > (Acmi?)
> >
> > 0 .1609 .1552 .137
> > 1 .1458 .1459 .127
> > 2 .1314 .1370 .118
> > 3 .1182 .1287 .111
> > 4 .1061 .1207 .103
> > 5 .0954 .1132 .097
> > 6 .0858 .1060 .091
> >
> > This is a large secondary coil 15.8" dia x 70" long. It is interesting
> that
> > the program outputs come closer together as the coil is raised and the K
> > Factors become smaller. As I said all the program outputs will be equal at
> K
> > = zero. We must be doing something right. (:})
> >
> > The data is entered in Java with password "Kurt1".
> > I couldn't find if Kurt made any K Factor test using the mutual inductance
> > test or the frequency test.
> >
> > John Couture
> >