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Op Amp Failure

  1. Apr 6, 2016 #1
    The output voltage of op amp is greater than the power supply voltage (+/- 5V). Is Op amp burned out?
     
  2. jcsd
  3. Apr 6, 2016 #2

    BiGyElLoWhAt

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    Probably. Have you tried replacing it?
    Is it of the order of one of your input voltages?
    Is your volt-meter or sensor hooked up to v out and not to your inputs?
    Do you possibly have it set up as +10/0V as opposed to +/-5V?
     
  4. Apr 6, 2016 #3
    Yes, I have replaced it and the result is still the same.
    I also set the power supply to +5/0V, the output has negative voltage too.
    I am connecting charge amplifier with pvdf film.
     
  5. Apr 6, 2016 #4

    BiGyElLoWhAt

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    What are you referencing as ground on your voltmeter? Is it the ground off of the power supply?
     
  6. Apr 6, 2016 #5

    BiGyElLoWhAt

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    Also, check the difference between your high and ground with a voltmeter.
     
  7. Apr 6, 2016 #6
    Ground the negative terminal of op amp.
     
  8. Apr 6, 2016 #7

    berkeman

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    What other voltage is connected to the output. The output of the circuit cannot be outside of the power rails without some other power source pulling that point up.

    Can you post your schematic?
     
  9. Apr 6, 2016 #8

    Averagesupernova

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    If the negative lead of the voltmeter is hooked to the negative supply when using a split supply setup I can see why you could get readings like this.
     
  10. Apr 6, 2016 #9
    This is the circuit.
     

    Attached Files:

  11. Apr 7, 2016 #10

    Svein

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    Your schematic does not show which pins you use to connect to the power supply.
     
  12. Apr 7, 2016 #11
    p
    pin 4 connect to -5v
    pin 7 connect to +5v
     
  13. Apr 7, 2016 #12

    Svein

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    Using 100MΩ feedback with a 0.22μF input capacitor is a recipe for trouble. The time constant is 22 seconds - so it will take forever to stabilize.
     
  14. Apr 7, 2016 #13

    Averagesupernova

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    I noticed this too. The whole things looks a bit odd. Wondering what is connected to the header?
     
  15. Apr 12, 2016 #14
    The header connects with pvdf film.
     
  16. Apr 12, 2016 #15
    Is 100M feedback with 0.22uF and 1000pF?
     
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