voltage follower

Discussion in 'Homework Help' started by kahafeez, Jan 16, 2009.

  1. kahafeez

    Thread Starter Active Member

    Dec 2, 2008
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    hi plz help me with the described problem.....
     
  2. Wendy

    Moderator

    Mar 24, 2008
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    I'm not sure what the problem is? You want to reduce the output voltage to ¼ of it's original value?
     
  3. kahafeez

    Thread Starter Active Member

    Dec 2, 2008
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    yes thats right, but i'm afraid that by attaching two resistors the oscillations might die as well....
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    2,536
    Why would it? Op amps have extremely low output impedance, so that shouldn't be a problem. This is homework, so I won't give the answer, but you have way too much attenuation on that voltage divider.
     
  5. hgmjr

    Moderator

    Jan 28, 2005
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    I agree with Bill that this looks like classwork for a course. I have moved it to the homework forum.

    hgmjr
     
  6. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    The Wien Bridge Oscillator needs a gain of 3.
    If the pot is set to a little more than 4.3k (close to half) then the gain is perfect.

    A voltage divider at the output of a 10k resistor in series with a 3.3k resistor will have 0.248 times the output across the 3.3k resistor if the load current is zero.
     
  7. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    :confused:
    AG, I think your mental calculator has failed you. The pot needs to be set to 8.6k for a gain of 3.
     
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