circuit analysis textbook

Discussion in 'Homework Help' started by yiannistamv, Jul 23, 2014.

  1. yiannistamv

    Thread Starter Member

    Jul 23, 2014
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    help for a topic in Fundamentals of Electric Circuits (5th Ed)
     
  2. yiannistamv

    Thread Starter Member

    Jul 23, 2014
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    i am studing circuit analysis from the book Fundamentals of Electric Circuits (5th Ed) and i have stuck please can someone help?
     
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  3. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    Equation 2.6.1 is correct.
    Don't forget that in mesh analysis we can choose current direction arbitrary.
    The author choose clockwise direction and by doing this he clearly defined polarities (the voltage drops) across resistors in the circuit according to the assumed directions of the mesh currents.

    [​IMG]

    And this is why KVL looks like this

    -12V + 4Ω*I + 2*Vo - 4V + 6Ω*I1 = 0

    And Vo do not show the voltage polarities across 6Ω resistor.
    This Vo show as how our VCVS will "sample/see" the voltage across 6Ω resistor.
    And for our assumed current direction VCVS will "sample" negative voltage.
    And this is why Vo = -6Ω*I

    And for example if we assume counterclockwise direction we have this situation

    [​IMG]

    And KVL

    4V - 2*Vo + 4Ω*I + 12V + 6Ω I = 0

    And

    Vo = 6Ω*I

    And finally we can use third method.

    -12V + 4Ω*I + 2*Vo - 4V - Vo = 0

    And Vo = -6Ω*I is negative because the Vo polarity is opposite to the direction of the loop current.

    So

    -12V + 4Ω*I + 2*(-6Ω*I ) - 4V - (-6Ω*I ) = 0

    -12V + 4Ω*I + 2*(-6Ω*I ) - 4V + 6Ω*I ) = 0

    -12V + 4Ω*I - 2*(6Ω*I ) - 4V + 6Ω*I = 0

    -16 - 2*I = 0

    and so on
     
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    Last edited: Jul 23, 2014
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  4. yiannistamv

    Thread Starter Member

    Jul 23, 2014
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    thank you very much Jony130
    bust what vcvs means? thank you for your time
     
  5. yiannistamv

    Thread Starter Member

    Jul 23, 2014
    35
    0
    Jony130 you are a life saver i find what vcvs MEANS i do understand thank you
     
    Last edited: Jul 23, 2014
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