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Phase Shifter

  1. Jan 21, 2012 #1
    1. The problem statement, all variables and given/known data

    Can somebody explain why the voltage across the capacitor (v0) lags vi?


    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     

    Attached Files:

  2. jcsd
  3. Jan 21, 2012 #2
    I proved it with a vector diagram.
    Let I be the reference phase ie. 0 degrees. Because the voltage across R is in phase with I it also has 0 phase.
    The capacitor voltage V0 lags I by 90 degrees ie. -90
    Vi=V0+Rvoltage.
    This shows Vi vector after I (R voltage) but before V0.
    Therefore Vi leads V0.

    I still would appreciate a more intuitive explanation if somebody has one.
     
  4. Jan 22, 2012 #3

    rude man

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    My old ARRL handbook explained this in a non-calculus way. I never bothered to try to understand it. It was obvious to me once I had diff eq's and transform techniques - meanwhile, I believe yours is the best intuitive explanation there is.
     
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