Magnetic levitation model

[pavwell]

Hello !
Please, could anyone hepl me with creating Magnetic Levitation of small ball model in EJS ?

Thanks a lot !

[Fu-Kwun Hwang]

Please provide more information: design/dimension of the system/shape/...etc (whatever  you have in mind)
And the physics to be modeled.

[pavwell]

Hello

Parameters and desing is in attachmement

[Fu-Kwun Hwang]

There is one thing I do not understand for the main equation in the above document


What is the meaning of in the above equatoion?

[pavwell]

Sorry !
I forget for this. ,,i,, is constant.

[Fu-Kwun Hwang]

Why there are two constant? , and what is the value of ?
L0=0.019 does it mean 1.9cm?

[pavwell]

L0 is 1.9 cm...

and ,,i, is : electrical power [A] and value is =0.33 Amper

[Fu-Kwun Hwang]

Do you mean i is electric current? (instead of power)
Is it a control variable? or it it a constant???

The system seems to be an un-stable equilibrium system. It need some feedback to make it stable, Right?

[pavwell]

Yes, it is electric current throught induction. And feedback is needed. In attachment I send you basic scheme.

[Fu-Kwun Hwang]

I try to implement a virtual feedback to create the following stable case.
However, you need to change parameters to fit with your own system.
 

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.magneticlevitation_pkg.magneticlevitationApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_magneticlevitation.jar' name='magneticlevitation6327' id='magneticlevitation6327' width='432' height='449' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=6327' target='smfejs'>Run simulation</a>

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!

[pavwell]

Thanks a lot for your job. But when I try to run in EJS 4.2, it gives me an compilation error. Please, what EJS version i need to use ??

[Fu-Kwun Hwang]

The above simulation was generated with EJS4.2

[pavwell]

please, could you make this project at EJS 3.4.7 ?? Thanks a lot !!!

[Fu-Kwun Hwang]

You should be able to copy the code to 3.47 if you open two version of EJS
Just define  the same variables, copy the same initialization/evolution/... and add similar GUI elements.
The only difference is that there is no two states button in EJS 3.47
So the play/pause button need to be separate as two buttons.

And you need to adjust the code to fit with your system.

I am willing to help you do you job: I already give you an example.
And you should be able to finish it by yourself! You need to at least try it!

[pavwell]

When i try to run this XML file under Ejs 4.2 , system gives me an error ! Compilation error. When i look over the code i found one red line ay=calF(....). Dont you konw what could be a problem ??

[Fu-Kwun Hwang]

I also use EJS 4.2 However, I did not find any error. So I do not know how to help.

The ay was defined as double with initial value "calF(y,vy)/m-g"
It can be re-assigned to 0. without affect the code.