Very Lost! Square wave coefficienrs/duty cycle

Discussion in 'Homework Help' started by labhelp, Feb 11, 2010.

  1. labhelp

    Thread Starter New Member

    Jan 28, 2010
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    Like i said i'm totally lost, anyone have any insight on any of these?:confused:
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    You might start by writing an expression which describes the time function [the pulse train] in a form which could be used to derive the Fourier series coefficients.

    Remember the a0 term is simply the average value of the pulse train and it is written formally as

    a_{0}=\frac{1}{T}\int^{T}_{0}f(t)dt

    So how would you write the function f(t) over the interval t=0 to T

    Looking at the waveform you will have to break it into several parts -

    from t=0 to αT0/2,
    from t=αT0/2 to (T0-αT0/2)
    and from t=(T0-αT0/2) to T

    The same will be true for finding the other Fourier coefficients.

    If you think carefully about the average value case [a0] you don't need to do any integration ......
     
  3. labhelp

    Thread Starter New Member

    Jan 28, 2010
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    0
    Okay i have,
    x(t)= A from t=0 to αT0/2,
    x(t)= 0 from t=αT0/2 to (T0-αT0/2)
    x(t)= A from t=(T0-αT0/2) to T

    then would the average be (A*αT0)/T ?
     
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    Correct.

    So if you make T=T0 (which is reasonable) what do you have for the average.
     
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