Connect with us

Weird diff amp behavior?

Discussion in 'Electronic Basics' started by Sam, Apr 8, 2007.

Scroll to continue with content
  1. Sam

    Sam Guest

    hey,

    i'm using a LM324 opamp configured as a diff amp. the inputs come
    from opamp followers, so there shouldn't be any loading issues.

    when i vary the input connected to the inverting (-) terminal
    everything's fine - i see a clear change in the differential output.
    but when i vary the input connected to the non-inverting (+) terminal
    there's no change in the output. any ideas? (fyi, diff gain is
    currently 4.7 [470s over 100s])

    thanks so much!,
    sam
     
  2. Eeyore

    Eeyore Guest

    How about posting a circuit diagram so as to check it's right ?

    Are any inputs close in voltage to the power supply voltages btw ?

    Graham
     
  3. Sam

    Sam Guest

    Are any inputs close in voltage to the power supply voltages btw ?
    yep - i forgot to use a split supply, so it was trying to drive the
    output below 0 when there was no way that was possible! thanks!

    -sam
     
  4. Eeyore

    Eeyore Guest

    It's nice when there's a simple answer ! ;~)

    Graham
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-