RF Resistance Calculation

#1 Posted: 11/29/2017 5:47:22 PM

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My first post. I'm trying SMath instead of MathCad P4.File not found.File not found.

Having difficulties transferring the RF resistance sheet from MC15. The ber, bei functions are missing. I added plugin EFI for Mathcad for the "Jv" (vs. Jn) function but it doesn't appear in the listing of available functions.

Attached is the mc file and my attempt to transfer to SMath.

I welcome the collabs help to move forward.

Sincerely,

nasch

#2 Posted: 11/29/2017 7:05:03 PM

Jean Giraud

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Wrote
The ber, bei functions are missing

Check if you can do something from the Smath built-in
mwbessl [i,j,k,y] from the f(x) menu.

#3 Posted: 11/29/2017 10:23:52 PM

Norm Schutzkus

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Thanks, for your reply. Unfortunately, I do not see "mwbessl..." listed. Maybe something that I need to activate? Is there a certain plugin I need to load?

Thanks, again

#4 Posted: 11/30/2017 1:23:56 PM

Jean Giraud

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Wrote
I do not see "mwbessl..." listed

You may have to install from the plugin list.
Click on "Tools", click "Plugins" ... install all.
Otherwise, rescue to "Smath Doctors" ... [Martin, Davide ...]

Bessel Midwest.sm (8 KiB) downloaded 38 time(s).

#5 Posted: 11/30/2017 2:32:40 PM

Norm Schutzkus

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Thanks, again. Unfortunately, the "mwbessel..." function are not defined. I have 23 plugins loaded, all with green check-marks so I think they are all working. "Install all" is not there.

Then again, I do not have admin rights (my work PC), so that may be a problem?

#6 Posted: 11/30/2017 3:02:34 PM

Jean Giraud

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Sorry Collab, can't help + ... hope Smath Doctors catch your pain.

#7 Posted: 11/30/2017 3:27:18 PM

Martin Kraska

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Try with my portable distribution, see signature. There, the mathlib.dll (mathcad special functions) is installed and the bitness of the executable is adjusted.

The screenshot below is from the interactive handbook. You find it using the [?] button in the toolbar in the distribution mentioned above.

Goto Plugins> EFI for SMath Studio> Special functions.

2017-11-30 19_23_19-SMath Studio 0.98.6484 - [Section Special functions.sm].png

Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx

#8 Posted: 11/30/2017 4:04:14 PM

Вячеслав Мезенцев

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Try this.

Links:

1. Cephes Mathematical Library.

Quote
There, the mathlib.dll (mathcad special functions) is installed and the bitness of the executable is adjusted.

mathlib.dll must be uninstalled (removed manually) from the Mathcad EFI plugin. Cephes Mathematical Library contains same functions.

Russia ☭ forever, Viacheslav N. Mezentsev

#9 Posted: 11/30/2017 4:17:14 PM

Вячеслав Мезенцев

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Wrote
Then again, I do not have admin rights (my work PC), so that may be a problem?

No, you have to set 32-bit version flag for the SMath Studio Desktop exe file.

Links:

1. Matlab C++ Math Library 2.1 (Win32)

Russia ☭ forever, Viacheslav N. Mezentsev

#10 Posted: 11/30/2017 5:22:09 PM

Norm Schutzkus

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Many thanks! "Jv" is now defined. But "arctg" is not. Another plugin?

#11 Posted: 11/30/2017 5:52:58 PM

Davide Carpi

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Wrote
Many thanks! "Jv" is now defined. But "arctg" is not. Another plugin?

Name of trigonometric functions depend on the function naming type in global settings of your smath studio; in your case you should look for atan

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#12 Posted: 11/30/2017 6:11:27 PM

Norm Schutzkus

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Thank you! Now it computes, but the value; Rac(100kHz) is negative. Should be 141.553Ohm/Mi. I need the "angle" function definition from Mathcad. angle(x, y) Returns the angle from the x-axis to a line containing the origin and the point (x,y). Results are in radians between 0 and 2π, excluding 2π.

#13 Posted: 11/30/2017 6:24:09 PM

Jean Giraud

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Wrote
angle(x, y)

NFG ... arg(1+1*i)=45°

#14 Posted: 11/30/2017 6:39:13 PM

Norm Schutzkus

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Using an old MC definition I obtained a better value:

#15 Posted: 12/1/2017 11:40:01 AM

Jean Giraud

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Using an old MC definition I obtained a better value:

These two documents may be of interest next blue moon.
Mostly if you need accurate Γ(x) ... Smath built-in ± 4/5 D

Cheers ... Jean

Bessel JY.sm (64 KiB) downloaded 34 time(s).

Maths Special Gamma(x) 15D.sm (75 KiB) downloaded 38 time(s).

#16 Posted: 12/1/2017 2:53:48 PM

Norm Schutzkus

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Many thanks!

#17 Posted: 12/6/2017 6:17:45 PM

Norm Schutzkus

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Thanks again for the collab's help. The work sheet displays the same result as MC. AC-DC Resistance Using Bessel Functions.sm (12 KiB) downloaded 26 time(s).

Now I have a fault using a modified sheet that the "Result is above max. allowed positive number."

. The limit for Rac(f) is 9.3MHz, then the error shows.

The result should be 219 micro-ohm/cm. Why the limit?

nas
Bellow Equiv Resistance.sm (14 KiB) downloaded 35 time(s).

#18 Posted: 12/7/2017 12:31:46 AM

Jean Giraud

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The result should be 219 micro-ohm/cm. Why the limit?

Here, it says ... Jv(,,) not defined.

#19 Posted: 12/7/2017 1:26:28 AM

Jean Giraud

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I understand the skin effect from my > 50 years back Electronics.
What I don't understand is the so complicated route to Ohms/MHz.
If you could tabulate some values of that Oms/MHz, I will attempt
a model fit ... something like I did for ITER [Cadarache].

#20 Posted: 12/7/2017 8:40:50 AM

Davide Carpi

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Wrote

Now I have a fault using a modified sheet that the "Result is above max. allowed positive number."

Something triggered in the factorization of the ratio be(...)/be'(...) you can make it working with a trick

2017-12-07 12_39_30-SMath Studio - [Bellow%20Equiv%20Resistance.sm_].png

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RF Resistance Calculation - Using ber, bei functions - Messages