Dear Zhang As a matter of fact, you should define the vector current density, as
follows: If the magnetic circuit is on the x-y plane, your vector current
density is J = |J|k,where
k is the unit vector in the z-direction. In this case, |J|=
Jz = I/S, where I is the total current in thecoil
and S is its cross section surface. Therefore, you must supply a Jplus current density, Jplus =|J| A/m^2 in one side of the circuit and Jminus
= -|J| Am^2, in the other side of the
circuit. Remember that the electric current density is continous
along the coil. Yours sincerely. Prof. Francisco Tejo P.S.: Perhaps, the figure below may be of some help to you.
Y |
|
_____
+| |-
Jz(plus)+| C |- Jz(minus)
+| o |-
______________+| r |-__________________ X
+| e |-
+| |-
+| |-
+|
|-
+| |-
_____
|
| -----Mensagem original----- Dear friends, I am a new comer in using FEMM3.3. When I was learning the example of DCMagnet, I was a little confused about the definition of current in the circuit. Due to the 2-D effect, we have to draw two parts for one excitation coil, and we have to define same current value "plus" and "minus" circuit for them. WhatI
want to know is that the value of the current should be the total current or half of the total current in the practical coil. Any help will be appreciated. Thanks Lefu Zhang __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com ------------------------ Yahoo! Groups Sponsor
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