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OPAmp Impedance Circuit problem

  1. Nov 29, 2011 #1
    I'm trying to solve this problem and the first 2 questions on it are giving me a tough time. Picture Attached.

    (1) Determine the equivalent impedance Zeq of the OpAmp circuit. Assume that the OpAmp
    is ideal.

    (2) Determine Rx, Lx, and Ry as a function of R, R1, and C such that Zeq of the equivalent
    circuit is equal to Zeq of the OpAmp circuit.

    any help with this is much appreciated. I can find the impedance of the equivalent circuit no problem but the opAmp version is tripping me up.
  2. jcsd
  3. Nov 29, 2011 #2
    forgot to attach in previous post here's picture

    Attached Files:

  4. Nov 30, 2011 #3


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    Staff: Mentor

    I haven't seen an op-amp with both inputs inverting, before this. Okay, so I've lived a sheltered life. :smile:

    Therefore, I have serious doubts about it giving the desired results. I think you might have to change the lower input to non-inverting (+). Does that make its analysis more in line with your expectations?
  5. Nov 30, 2011 #4


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    Staff: Mentor

    R and C form a potential divider, dividing the input voltage and impressing it on the (+) input of the op-amp.
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