Only positive differential op amp

Discussion in 'The Projects Forum' started by mcgyvr, Aug 3, 2012.

  1. mcgyvr

    Thread Starter AAC Fanatic!

    Oct 15, 2009
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    How would I construct a circuit similar to a differential op amp but I ALWAYS want the output to be positive.
    So for example V1=non-inverting pin and V=inverting pin
    When V1 is 1.5V and V2 is 3V I want Vout to be 1.5V
    Then if V1 is 3V and V2 is 1.5V I want Vout to still be 1.5V
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    An instrumentation amplifier followed by a Precision Rectifier. Use google for links. But this one is one of the best http://sound.westhost.com/appnotes/an001.htm
    You did not say anything about bandwidth. Most of the Precision Rectifier circuits will work fine up to around 100 KHz at least. Above that it may be harder to find a proper solution
     
  3. mcgyvr

    Thread Starter AAC Fanatic!

    Oct 15, 2009
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    blah..too many parts :(
    maybe I'll just take care of it in software..
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
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    Well have it your way then. Nah just joking. If you can do it software. It will be as good as any solution. More ideal than the analog solution
     
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