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Op amp current supply

  1. Aug 8, 2009 #1
    Do opamps have current limit, I have an OP-27 dual supply connected to 2 9V batters the battery measures 3 Amps and 16 volts is this too much current?
     
  2. jcsd
  3. Aug 8, 2009 #2

    berkeman

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    Staff: Mentor

    There is some circuit problem. The OP27 is a standard opamp, so it will not draw or drive currents much over a few 10's of milliamps.

    http://www.analog.com/en/other/militaryaerospace/op27/products/product.html

    Check the power connections (maybe the +/- supplie connections are reversed?). Also, be careful to take usual ESD/handling precautions, as touching a powered-up exposed circuit can cause latchup.

    When you power up your circuit (assuming the 9V batteries aren't dead by now), what gets hot?
     
  4. Aug 8, 2009 #3
    resistors I put on the + supply got hot anything less than 10k just burned
     
  5. Aug 8, 2009 #4

    berkeman

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    Staff: Mentor

    Can you post your schematic? Something in the middle must be hooked up wrong. If you do not load the opamp, are the currents small?
     
  6. Aug 8, 2009 #5
    Its a very simple 2 opamp circuit so it must be the op amps I will replace them.
     
  7. Aug 8, 2009 #6
    But my opamps were brand new, when I connect the batteries to the opamp circuit I connect the ground first then + then -, is this ok or is it damaging the amps?
     
  8. Aug 8, 2009 #7

    berkeman

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    Staff: Mentor

    Not sure without a schematic. Generally you should use a DPDT switch to connect both of the rails at the same time.
     
    Last edited: Aug 9, 2009
  9. Aug 9, 2009 #8
    Sounds like it's mis-wired. It's easy to run high currents through the device's substrate. For example, just reversing the power supply connections will draw a huge current, while only dropping about .6-1 volt.

    -Mike
     
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