voltage follower

Discussion in 'General Electronics Chat' started by jjkk, Jan 20, 2009.

  1. jjkk

    Thread Starter Member

    Jan 16, 2009
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    can i input a sine wave from asignal generator to a op amp voltage follower
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    A qualified...yes.

    More details???

    Ken
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    Of course it can be led in as an input, but without any details it's impossible to say how any op amp would respond.
     
  4. jjkk

    Thread Starter Member

    Jan 16, 2009
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    i am using the voltage follower to drive a transformer(basically 2 coils wound in a tube) .there is parallel LC circuit to resonate it. but i am not getting anything. how will i drive the transformer to get a better output
     
  5. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    How about posting a schematic?

    Ken
     
  6. jjkk

    Thread Starter Member

    Jan 16, 2009
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    i only have a scribbled schematic. i can describe it. signal generator-voltage follower-capacitor parallel to the primary -output from secondary.can anyone tell me how to drive the coils to get a better output
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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    You probably need a more capable source to drive the transformer. We need details to assist with your problem.
     
  8. thingmaker3

    Retired Moderator

    May 16, 2005
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    Two coils wound on a tube might not give a very good k value. K is the efficiency of the transformer, always less than 100%.

    Are the windings one atop the other? Separated? Wound together with the conductors side-by-side?

    Is the tube of powdered ferrite? Iron? Plastic?

    What frequency are you injecting?
     
  9. jjkk

    Thread Starter Member

    Jan 16, 2009
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    the winding are separated.the tube is an insulation material i used a ferrite piece to go thru it.when it reach the middle of the coil it gives o/p
     
  10. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    What frequency do you use? What value is the capacitor? Is it electrolytic or some other type?

    If you don´t answer our questions, we can´t help you.
     
  11. jjkk

    Thread Starter Member

    Jan 16, 2009
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    i am using 22kHz sinewave . i calculated the capacitor value as 0.3uF. so it resonates at a that frequency.but the output is disturbed.
     
  12. beenthere

    Retired Moderator

    Apr 20, 2004
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    What is the impedance of the transformer primary? Can your signal generator drive that load?
     
  13. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    The capacitor has to be ceramic or film, polarized electrolytic cap will distort one polarity of the sine wave.
     
  14. jjkk

    Thread Starter Member

    Jan 16, 2009
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    impedence is arround 170uH. i am using non polariced capacitor . do i have to increase the no. of turns to get better performance
     
  15. Audioguru

    New Member

    Dec 20, 2007
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    An opamp can drive an impedance of 2k ohms and higher.
    A lousy old 741 opamp works at frequencies of only 9kHz and lower.
     
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