Author Topic: Ejs Open Source Direct Current Electrical Motor Model Java Applet ( DC Motor )  (Read 74424 times)

lookang

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Let me try to fix the bug.
It is rather complex now and unreasonable to ask u to debug it. :)
I have a splitring function now that is difficult to implement without understanding all the codes.
I think I need to invent another way for the electrons to be control instead of using only sign as a means of changing the current n electron .
I will try to add a new variable to the checkbox to control the electron sign.



Btw
You can download any older jar it should have all the files there.

lookang

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Fixed! amazing i managed to fix bug cause i was so worried i couldn't find it and come up with a solution.
indeed some rest and try again helps for this situation. when tired, just rest and let it incubate in my mind. creativity works with there is enough time, not pressure.
this top post is the latest sim!

17 April 2011 (Saturday going Sunday at midnight after thinking about it every moment for a saturday)
major break through in bug fix now electron/current + splitring/ or without all bugs fix
added show graph angle, magnetic force, magnetic torque vs time and angle included even with data analysis
add N number of turns in coil
add inertia
add lengthx as slider with all associated drawing of the particles
add lengthz as slider
add Torque
fix a bug in evolution page domega/dt = (getAlpha(cta) -bf*omega)/Inertia where getAlpha(cta) is magnetic torque a2*Math.abs(Math.cos(cta)) where a2 = a2=N*I*B*L*b*1;
new assumption in sim is inertia is not affect by N, each slider controller is for conceptual exploration, not exactly mimicking real equipment so to speak.



Attached is my latest worksheet for research
« Last Edit: May 04, 2011, 05:20:32 pm by lookang »

lookang

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latest copy for research

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

lookang

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a collaborator friend teacher tested the worksheet and gave good feedback
below are the comments and my proposed solution to co-developed the lesson.


Based on the pages in the word doc:

Page2, last paragraph, line 2. I was initially confused by the y-direction force indicated. It's after tinkering that i realised your Z is vertical, y is horizontal. Could be a potential confusing point for my students.

solution:
implemented decoration = axes


Page 4: In Qn4, the attached ss of the sliders is very dark, especially the 2nd and 3rd one. Guess the students can refer to the simulation for these.

made alpha = background white

Page6: Qn11. Sorry, i dotn know the answer to this. Qn 10 seems to be wanting me to know the coil might be pulled apart if the forces are large enough. . . but why it doesnt, i dunno.

Yes! the structural strength of the coil keep the shape intact.
in addition, if students can explain why real Dc motor are with a iron core to strengthen the B field as well as provide the material of the coils to remain its shape.


Page 7. Explore Activity B. Do they have to design experiments for all 3 parts? How much to design? Seems no need to write, but simply just rotate among the variables given as independent variables? How much time would that entail?
Page 7 Qn 13. Would the students know which "inquiry learning" you are refering to?

so long as it takes for student to explore meaningfully as productive activity, teacher need to support the weaker groups?
inquiry learning is a standard word in MOE science curriculum framework  
http://www.moe.gov.sg/education/syllabuses/sciences/files/science-lower-secondary-2008.pdf page 1
should be fine :)


Page 8. Qn 15: "....by varying..." this i changed on my system.
Page 8. Extend problem. Graphs. There are redundant axis labels. Eg the first pair only refers to FBy rather than the indicated angle and TB. Can these be removed? On my system, i just cover the redundant ones with a rectangle.

agreed

Page 9. Graphs, same problem as Page 8 graphs. Same solution.

agreed

Page 10. Qn25. the angle cta . . . can change to some other symbol thats more angle-like? theta or alpha or something? I dunno the reason for the choice of "cta".

beta better? = ? i changed in my worksheet
it is intended not to cause confusion with the other typical symbols commonly used and the simulation already used ?, ?



lastly, just a general comment that this worksheet requires more brains and thinking than i initially expected. Its probably because I'm too lazy to think through the entire worksheet properly, but just scanning through. Some answers are not immediately obvious to me.

that is a good observation, the learning is intended to be more thinking than memorization :)

lookang

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26 April 2011
added more text battery brush split ring coil to situate the association of the drawings more clearly labels? will deactivate them
F drawn shorter now
added axes a powerful feature to allow sim to display in XYZ to XZY so that it is immediately the same setup as some textbooks and internet graphics
added decoration = axes as suggested by collaborator Sim KS
added worksheet is jar itself for scalability as lesser chance of losing curriculum material to accompany the simulation
added angle drawn theta with checkbox
added checkbox to show hide the magnets for printing the 3 view front side and top
complied in Ejs 4.3.3 as the latest version is causing some display frame ghost lines with changing orientation
« Last Edit: April 26, 2011, 09:45:56 pm by lookang »

ahmedelshfie

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Good job,i like the modified version by lookang could you explain about data tool i didn't understand the job of this option  :o

lookang

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Hi ahmedelshfie,
the intend is to allow a deeper exploration possible through the data analysis and perhaps even some simple mathematical model equation to curve fit the data.

exactly what to do, i have not figure out yet.
the feature was ported from the AC generator as there is a sine and cosine curve for the emf and current.

Dc motor i need to think what to do in order to deepen the appreciation of the physics through mathematical analysis of the data.


any suggestions is welcome!

ahmedelshfie

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actually i was interested to know what is the job to this tool i see the applet that you done is too good
I like the modified version later have free time im gonna publish on egtecno.com.
oh by the way my name is just ahmed but elshfie name my family  ;D
Good job what you done.

lookang

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08 July 2011
fixed a bug with B and Bcorrect after a sharing that i realized the left hand rule should be correct now.

lookang

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same problem in the iMac.
the default Java Machine is /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/

java.lang.NullPointerException
   at users.sgeducation.lookang.DCmotor10_pkg.DCmotor10View.reset(DCmotor10View.java:3835)
   at org.colos.ejs.library.Animation.reset(Unknown Source)
   at users.sgeducation.lookang.DCmotor10_pkg.DCmotor10Simulation.(DCmotor10Simulation.java:23)
   at users.sgeducation.lookang.DCmotor10_pkg.DCmotor10.(DCmotor10.java:147)
   at users.sgeducation.lookang.DCmotor10_pkg.DCmotor10Applet.init(DCmotor10Applet.java:25)
   at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Plugin2Manager.java:1640)
   at java.lang.Thread.run(Thread.java:680)

it works well in windows.

zionism07

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Hi Lookang,

I've problems trying to download the jar file from the link stated in the threads.

It seems like the zip file only contains the source files but not the jar.

is it possible for you to upload the jar version of the applet?

It's really useful for the kids to understand the concept of DC motor.

lookang

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Hi Lookang,

I've problems trying to download the jar file from the link stated in the threads.

It seems like the zip file only contains the source files but not the jar.

is it possible for you to upload the jar version of the applet?

It's really useful for the kids to understand the concept of DC motor.
Hi
Download EJS jar file(1686.6kB):double click downloaded file to run it. (157 times by 51 users) ,
The file is actually a jar file.
I suspect you are using Singapore school
SSOE machine on Internet explorer ?
U need to use Firefox to download the file correctly as SSOE Internet explorer some how associate the file as a zip extension instead of a jar extension.

Could u try to download at home using your own PC ?

zionism07

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Hi Lookang,

yah, i'm actually "stuck" in a local sec sch trying to push IT initiatives for physics within my dept.

Haizz, it's really a tough job to plough the whole internet finding resources and programs created by others, in a way, praying that someone has really come up with suitable programs and uploads them on the internet.

Speaking of the file extension, u gave me the idea to add ".jar" to the document name before saving it and it works.

Thanks for your efforts in pushing great reforms to our sch system as I feel it's still lacking on the IT fronts.

lookang

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3 requests already possible!
enjoy!

received an email and Facebook request for the following features! actually it is all possible already hahaha.

This is the most fantastic simulation for DC motor, thanks to Professor Fu-Kwun Hwang!


















Leong Tze Kwangposted tohttps://fbstatic-a.akamaihd.net/rsrc.php/v2/yI/r/aoGVaWCuzdk.png); background-position: -134px -135px; background-repeat: no-repeat no-repeat; background-size: auto; border: 0px; height: 9px; margin: 0px 5px; width: 11px;" />Loo Kang Lawrence Wee





31 minutes ago near Singapore · https://fbstatic-a.akamaihd.net/rsrc.php/v2/ya/r/wjorsTVUCAf.png); background-position: -219px -325px; background-repeat: no-repeat no-repeat; background-size: auto; bottom: -1px; display: inline-block; height: 12px; margin-bottom: -5px; margin-top: 2px; position: relative; vertical-align: top; width: 13px;">









  • Hi Loo Kang, I'm using your motor applet (http://weelookang.blogspot.sg/2010/06/ejs-open-source-direct-current.html) and really like your applet. Is it possible to make the following changes when you are free to better serve my teaching needs. Thanks.
    1) Adding arrows to show current direction instead of electrons motions which are too fast and too small to see.
    2) Adding an arrow for force like this video to show the direction and magnitude of the force
    https://www.youtube.com/watch?v=Xi7o8cMPI0E&feature=player_embedded
    3) Adding a button to prevent angular acceleration (i.e. rotate at constant speed). The motor spins too fast after a while and is very hard to analyze. Alternative add in back emf so that it is more realistic and hence will have a maximum angular velocity.
    Thanks so much for helping the community of teaching and
    learning. https://fbstatic-a.akamaihd.net/rsrc.php/v2/ym/r/0Gtf20tdcer.png); background-position: -17px -717px; background-repeat: no-repeat no-repeat; background-size: auto; display: inline-block; height: 16px; vertical-align: -3px; width: 16px;">










1. click on the check-box velocity.




request 1.Adding arrows to show current direction instead of electrons motions which are too fast and too small to see.

must sure current flow check-box is selected (YELLOW) and velocity (MAGENTA)



2. click on the FBy check-box




request 2) Adding an arrow for force like this video to show the direction and magnitude of the force

https://www.youtube.com/watch?v=Xi7o8cMPI0E&feature=player_embedded

already available, select FBy checkbox!





3. slide Ff = -0.1*w  for example, Friction force = -0.1*angular velocity, the higher the lower the terminal rotational speed






request 3) Adding a button to prevent angular acceleration (i.e. rotate at constant speed). The motor spins too fast after a while and is very hard to analyze. Alternative add in back emf so that it is more realistic and hence will have a maximum angular velocity.

slide slide Ff = -0.1*w  for example, Friction force = -0.1*angular velocity, the higher the lower the terminal rotational speed







enjoy!




http://weelookang.blogspot.sg/2010/06/ejs-open-source-direct-current.html

Ejs Open Source Direct Current Electrical Motor Model Java Applet ( DC Motor ) « on: October 23, 2009, 06:14:56 PM » posted from:Singapore,,Singapore

 author: fu-kwun hwang and lookang https://dl.dropboxusercontent.com/u/44365627/lookangEJSworkspace/export/ejs_users_sgeducation_lookang_DCmotor10.jar 


lookang

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« Last Edit: December 16, 2015, 11:03:08 am by lookang »