# Fourier series waveform

1. Jul 6, 2014

### suv79

1. The problem statement, all variables and given/known data

what type of waveform would this make ?

2. Relevant equations

V(t)=2/π(sin(ωt)+1/2sin(2ωt)+1/3sin(3ωt)+1/4sin(4ωt)+.........)

5sin(ωt)+5sin(2ωt)+5sin(3ωt)+5sin(4ωt).....

3. The attempt at a solution

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Last edited: Jul 6, 2014
2. Jul 6, 2014

### suv79

all that I have read about Fourier series, it uses odd number for 'n' to make an sawtooth waveform,

5sin(ωt)+5sin(2ωt)+5sin(3ωt)+5sin(4ωt)..... this is not add together as it is increasing the voltage ?

Last edited: Jul 6, 2014
3. Jul 7, 2014

### cpscdave

Where did you come up with

4. Jul 7, 2014

### suv79

that is from the input, see the 2nd attached.
i dont understand what waveform the input will be making.

Last edited: Jul 7, 2014
5. Jul 7, 2014

### cpscdave

Those inputs I don't think are valid, cause you are right as they stand they'd keep adding.
Generally with fourier series as the frequency of the component goes up the scalar goes down.
Take a look at http://en.wikipedia.org/wiki/Fourier_series
example 1 is actually the sawtooth waveform. You'll notice that is not 5 as you have in your example but rather $$2*(-1)^{n+1}\over(\pi*n)$$

6. Jul 7, 2014

### suv79

the 5 is Peak amplitude.

7. Jul 7, 2014

### cpscdave

Well then it would be multiplied by 5. The peak amplitude is generally taken into account when you do the integral to calculate Bn & An