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LM 741 Questions

Discussion in 'Homework Help' started by ElectronicTy, Mar 8, 2018.

  1. ElectronicTy

    ElectronicTy New Member

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    Hi all i have a problem with a LM741 op-amp,
    when calculating the output voltage i should have when inputting 12vpp using the formula Vo = Vi(1+Rf/Ri) and the values being vi = 12 rf = 6k Ri = 1.5k i should be having an output of 60v, but when building and simulating my design i only have 27.8v.
    it works when i use 2vpp as the output is the exact same as my calculations.
    any help would be great, below is the circuit
    Thanks
    circuit.png
     
    Last edited: Mar 8, 2018
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    As your supply is only 30V, how do expect the output to go higher than that?.
     
  3. Les Jones

    Les Jones Well-Known Member

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    You can't get an output voltage that is higher than the supply voltage.

    Les.
     
  4. dave miyares

    Dave New Member

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  5. ElectronicTy

    ElectronicTy New Member

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    Thanks both,
    sorry i'm a beginner and supposed to be writing a report on the results! makes a lot more sense when someone points it out ha ha.
    do you know if 30v is the max supply for a LM741
    Thanks again
     
  6. JimB

    JimB Super Moderator Most Helpful Member

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    Have a look at the datasheet.

    I have also corrected the part number in the tread title.

    JimB
     
  7. crutschow

    crutschow Well-Known Member Most Helpful Member

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    If you want to continue with learning electronics, one of the first things you should do is learn to read datasheets.
    It will save you a lot of grief and misunderstanding in using a part.
     
  8. dave miyares

    Dave New Member

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  9. audioguru

    audioguru Well-Known Member Most Helpful Member

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    The 741 opamp was designed 50 years ago (!) and modern opamps are much better.
    Its datasheet shows that with your plus and minus 15v supply some 741 opamps cannot produce more than 12V into a 10k ohms load.
     

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