Mesh current Analysis explanation is no good

Discussion in 'Feedback and Suggestions' started by Xhacker, Apr 26, 2009.

1. Xhacker Thread Starter New Member

Apr 26, 2009
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I went to this page http://www.allaboutcircuits.com/vol_1/chpt_10/3.html to learn about mesh current analysis, yet the explanation given is not well explained and wrong as well.

The author of this guide explains that the direction of I2 on the right goes clockwise by drawing a circular directional arrow going clockwise. Yet he says that by "Creature of Habit that I am.." decides to start counterclockwise, which makes his explanation wrong already. Further on he gets an answer of -1mA and says that its wrong because the current was supposed to go counter-clockwise. Not only does he fail to explain this or give an equation for this, but the new picture shown with the correct current direction has R2 with the + and - symbols reversed, making the entire point invalid and incorrect.

I would like a correct explanation on mesh current analysis, as this is the only website that bothers to trys to discuss it properly.

2. Nanophotonics Active Member

Apr 2, 2009
365
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It's to be noted that the "clockwise & anti-clockwise" notion when dealing with mesh analysis is completely arbitrary. One can decide either way. It's just a convention expressed as a concept of one "current" relative to the other "current" as in, for example, Relative Velocity. Maybe the problem here could be word choice, but it emphasizes on the arbitrary nature of carrying out mathematical analysis on mesh circuits. Hence, a negative current implies a positive current of same magnitude but flowing in opposite direction. It is understood.

Thanks.

Last edited: Apr 27, 2009
3. bmealhendi New Member

Mar 23, 2009
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set the current ethier CCW or CW as nanophotonics said is arbitrary but if u set the current in one mesh CCW u must complete the other meshes in the same circuit CCW also,,,

4. t_n_k AAC Fanatic!

Mar 6, 2009
5,448
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I don't think any constraint such as adopting the same convention (CW or CCW) for all mesh currents is necessary. One can have a mixture of CW and CCW conventions in the same analysis. The outcome will be the same provided the mesh "rules" are correctly applied.

5. Nanophotonics Active Member

Apr 2, 2009
365
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Yes that's the point. It's only a matter of making life easier to stick to a particular convention and avoid confusion.

Thanks.