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Homework Help: Simplify the following circuit (all impedances)

  1. Apr 26, 2010 #1
    1. The problem statement, all variables and given/known data
    Calculate the equivalent impedance about terminals A and B.
    [PLAIN]http://img218.imageshack.us/img218/9335/circuits827.png [Broken]

    Z1 = -j2 ohms
    Z2 = 1 ohm
    Z3 = j2 ohms
    Z4 = 2 ohms

    2. Relevant equations
    Adding parallel: Zeq = z1*z2/z1+z2
    Adding in series Zeq = z1+z2

    3. The attempt at a solution
    I honestly have been staring at this problem for hours and cannot figure it out. I'm beginning to wonder if you have to perform a Y to Delta transformation about Z1, Z3, and Z4. Without doing that I cannot see how to simplify this problem. Is there another way? Or, is that the only way to solve it by doing a Y to Delta transformation about Z1, Z3, and Z4.

    Help / advice much appreciated in advance.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Apr 26, 2010 #2
    You are working way to hard.
    Z1 & Z4 are in parallel, then in series with Z3, and that result is in parallel with z1.

    Just draw the circuit with node A at the top and Node B at the bottom.
    Last edited by a moderator: May 4, 2017
  4. Apr 26, 2010 #3
    Thank you, haha yes I was over analyzing it way too much, I missed that.

    Thanks again!
  5. Apr 28, 2010 #4
    Drawing circuits in a 'non-standard' organization is a favorite way to confuse.

    You should see what you can do to a bridge circuit to make the arms look out of balance.
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