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I need help in OP AMP circuit

  1. Feb 7, 2016 #1
    hi, i reallyt need help in this question.
    i tried this but i am not sure how to start this, so if you can provide me little help i will really appreciate it

    its based on OP AMP circuit

    thanks guys

    Attached Files:

  2. jcsd
  3. Feb 7, 2016 #2
    This looks like a homework problem. Try the homework forum.
  4. Feb 8, 2016 #3

    jim hardy

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    Science Advisor
    Gold Member

    "Dr Hardy's Painless Method"

    Here's what i find the simplest approach, and i doubt you'll find it in your textbook:
    OP-amp circuits do algebra.
    They do it by forcing the OP-amp's inputs equal.
    It is the duty of the circuit designer to wrap the OP-amp with a circuit that allows it to do that.
    So --- see if these three simple steps work for you,

    1. Write the equation for voltage at opamp's - input , looks to me trivial by inspection , V- = Vo/2 .
    2. Write the equation for voltage at opamp's + input, it's a function of Vin and some constants, V+ = f(Vin) , you should find that f(Vin) easily with laws of Ohm and Kirchoff
    3. Set those two equations equal , V+ = V- , and solve for Vo/Vin .

    Then you should prove to yourself that's the same result you'd get by your textbook method

    old jim
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