Feedback in transistors

Discussion in 'Homework Help' started by Romsha, Sep 6, 2015.

  1. Romsha

    Thread Starter New Member

    Nov 29, 2013
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    What is the difference between Shunt voltage feedback and series feedback? I am not asking in terms of change in input/output impedence or any other parameter but how does feedback signal mixes with the input? Because I unable to differentiate between their circuits.
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    The input summing is shunt when the feedback resistor is connected to the same node as where the input source is connected. Otherwise we have series feedback.
    e.gif
    Also there is a clear way to differentiate between the two types of feedback (Current/Voltage). If you short the output (making Vout = 0), and the feedback signal goes to zero, you've got Voltage feedback. If you disconnect the load (making Iout = 0), and the feedback signal goes to zero, you've got Current feedback.
     
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  3. Romsha

    Thread Starter New Member

    Nov 29, 2013
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    thank you! for explaining it. But why it is called shunt and series? Does series here means series circuit? It is the source of confusion.
     
    Last edited: Sep 6, 2015
  4. Jony130

    AAC Fanatic!

    Feb 17, 2009
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    Well in my country we use word Parallel instead-of a"shunt". Because the feedback signal is fed back in parallel ( shunt) with the input.
    e3.GIF
    Or simply feedback signal shunt some part of the input current.

    As for the series feedback ... simply the error voltage is fed back in series with the input signal.
    e2.GIF
     
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  5. Romsha

    Thread Starter New Member

    Nov 29, 2013
    8
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    yup concept cleared thanks again. :)
     
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