On Thu, 17 May 2001 16:39:19 -0500, David VanHorn wrote:

>At 05:32 PM 5/17/01 -0400, Sean H. Breheny wrote:
>>Hi Dave,
>>
>>I think this has come up before but I can't shut up :-) Why do you say that
>>a sine wave contains harmonics? My guess is that you are saying that in
>>practicality, when you try to create a sine wave, you can't totally avoid
>>harmonics and you usually end up with mostly even ones, which may be true.
>>Nonetheless, a pure sine wave has no harmonics because that is what Fourier
>>series are based upon, sine waves. I think it is especially misleading in
>>this case to state that a sine wave is an infinite series of harmonics,
>>too, because this will lead people who are trying to create sine waves to
>>think that they must ensure the presence of such harmonics, when in reality
>>it is best to reduce them as much as possible because as long as they are
>>present, you don't have a perfect sine wave (the total harmonic distortion
>>is greater than 0).
>
>
>Sorry, brain short.  :)
>Correct. Sine is F only.
>Square is F plus 3F, 5F.... in decreasing infinitum

Even harmonics make up a *triangle* wave.

f + 2f + 4f + 6f ...

Dan

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