Nodal analysis with dependent source.

Discussion in 'Homework Help' started by Jess_88, May 2, 2011.

  1. Jess_88

    Thread Starter Member

    Apr 29, 2011
    174
    1
    hi guys :)

    For this question I need to fined V1,V2 and V3 using nodal analysis.
    The resister values are in S... which I'm guessing is admittance (my lecturer used Y for admittance in his notes :confused:).

    so here is the cct
    [​IMG]

    for the analysis I am unsure as to the voltage between V1 and V2... I'm assuming its just 2Vo.

    I'm realy not sure if I constructed my equations correctly...

    here is what I have for my equations.
    s = 1/R
    At node V1
    eq1) 2(V1 -V2) +2 + 2Vo = 0

    at node V2
    eq2) 4V2 -2Vo + 8(V2 - V3) = 0

    node 3 = 13V
    Vo = 1(V2)

    substituting V3 = 13 and Vo = V2
    eq1) 2(V1 - 13) + 2 + V1 + 2V2 = 0
    3*V1 + 2*V2 = 24

    eq2) 4*V2 + 8*V2 - 8*V3 - 2*V2 = 0
    10*V2 = 8*13
    V2 = 10.4V

    subbing V2 into eq1
    V1 = 1.1V


    Thanks guys :)
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    Last edited: May 2, 2011
    Jess_88 likes this.
  3. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    Unfortunately your equations are not correct.

    You seem to be treating the voltage controlled voltage source as a current source.

    Keep in mind that V2=Vo.

    So it's worth noting that V1=V2+2Vo=3Vo

    I would combine Node 2 (LHS of equation) & Node 1 (RHS of equation) as

    8(V3-V2)-4V2=V1+2(V1-V3)-2

    Then substitute V1=3Vo, V2=Vo & V3=13 and solve for Vo
     
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  4. Jess_88

    Thread Starter Member

    Apr 29, 2011
    174
    1
    so I get
    2 + 10V3 = 21Vo

    subbing V3 = 13V
    V1 = 18.857
    V2 6.285

    correct?
     
  5. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    Your answers check out.

    I would give some attention to Jony130's post.

    You will need to understand how to deal with supernodes as they crop up from time to time in circuit analysis problems - so it would be worth doing some reading on that topic.
     
  6. Jess_88

    Thread Starter Member

    Apr 29, 2011
    174
    1
    excellent :)
    thanks guys
     
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