# Sine waves

Discussion in 'Electronic Design' started by john, Sep 9, 2006.

1. ### johnGuest

Hi,

Does sine wave has more than one harmonics at lower and higher
frequncies? or whatever the frequency the sine wave has always one
fundamental frequency or harmonics. Please accept my apologizes if I am
asking the wron question?

John

2. ### Boris MoharGuest

No harmonics for a sine wave that has existed and will exist for all eternity
at same amplitude and frequency.

Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place

3. ### johnbscotGuest

I don't understand why you are asking the question in the first
place.... it is clearly obvious that a pure sinewave has no harmonics!

John

4. ### Bob EldGuest

A pure sine wave has one harmonic, the first harmonic otherwise known as the
fundamental. It has no higher harmonics. However any real sine wave
generated with normal electronic oscillators, etc. will never be absolutely
pure and will., therfore, have some harmonics as well as non-harmonic noise.
For example if a wave is 99.9% pure, it will have noise and harmoncis adding
to 0.1%. This level is only 60dB below the fundamental so even that is not
very pure by some standards. Sub harmonics below the fundamental in
frequency can exist but are usually not present.

5. ### Phil AllisonGuest

"Bob Eld"

** Since this NG (and the question) is about science and electronics and
NOT musical terms, the above is incorrect.

Harmonics are frequencies that are integer multiples, 2, 3, 4, 5 etc, of
the fundamemetal frequency of a complex wave.

........ Phil

6. ### John LarkinGuest

Most engineers pretty much equate "harmonic" with "Fourier component",

0th harmonic = DC term

1st harmonic = fundamental,

etc.

But it's just a convention, so there's no hard right or wrong.

John

7. ### Bob EldGuest

I believe you have it backwards. In music the first overtone is the second
harmonic which is 2 times the fundamental in frequency. The fundamental in
engineering, audio and related fields is the first harmonic even though the
word "harmonic" is misleading. As was mentioned, the terminology comes from
the Fourier series.
Your statement: "Harmonics are frequencies that are integer multiples, 2,
3, 4, 5 etc, of
the fundamemetal frequency of a complex wave." That is a true statement but
don't forget that "1" is also an integer.

8. ### Phil AllisonGuest

"Bob Eld"
"Phil Allison"

** I believe you have your head permanently stuck up your arse.

** Yawn - not even on the point at issue.

** Yawn - just restates the original error.

** Not mentioned by you, me or the OP.

Plus not relevant anyhow.

** How typically asinine & autistic of you.

Cut the verbal diarrhoea.

A pure sine wave is one that simply has NO harmonics present.

....... Phil

9. ### Guest

This gets down to mere semantics, but I have to agree,
you never really hear people talking about a "first harmonic".
They almost always call the main frequency the "fundamental", and
only use the term "harmonic" for integer multiples of the fundamental,
2x, 3x, 4x, and higher.

But the kicker here is that people will often use the term
"Half-harmonic", to indicate a spur 1/2 the fundamental.
When occuring in power amplifiers, these mysterious half-harmonics
are thought to be caused by some sort of varactor effect.
When they occur in frequency doublers, the failure to suppress
and filter the original fundamental is the obvious cause (the
2nd Harmonic essentially becomes the new fundamental).

Slick

10. ### Phil AllisonGuest

** The implied meanings of words an terms is hardly trivial.

It is the way humans communicate.

** Google gives many hits on the term.

Mostly in the musical context.

** A Google search gives that definition exactly, over and over.

** Correct usage depends on the context and the audience.

Long as the aim is to inform and not confound.

......... Phil

11. ### John LarkinGuest

Techs like to argue over terminology and definitions, as if they were
important. All that really matters is the math.

John

12. ### Bob EldGuest

I see that Fillup Asshole has raised his ugly head again with his usual
polite crap and name calling. This, of course says more about him than about
me or any other poster he denigrates of which there are quite a few. It
seems he has little to say that is not an insult or asinine retort rather
than a constructive discussion of the subject at hand. It's too bad to waste
bandwidth on such a jerk, maybe he should swim with the sting rays down
there or at least crawl back under his rock gooday mate!

13. ### Jim ThompsonGuest

[snip]

If you would simply plonk Fillup Asshole, you would not be bothered.

...Jim Thompson

14. ### John WoodgateGuest

In message <>, dated Sun, 10
How dull, though! Besides, if you plonk him, you can't call him Phyllis
Alison when he becomes more than usually obnoxious. He doesn't like
that.

15. ### John LarkinGuest

I suppose you've noticed how absolutely humorless Phyllis is. What a
way to live!

John

16. ### Jim ThompsonGuest

I think I need to get the latest version of Agent. Looks like "Ignore
Sub-thread" may allow me to even miss replies by others to Allison,
Eeyore, Frank B, Sloman, etc... so they will truly cease to exist ;-)

...Jim Thompson

17. ### John WoodgateGuest

In message <>, dated Sun, 10
He did post a joke once. I suspect his most colourful posts are fuelled
by Bundaberg.

18. ### Michael A. TerrellGuest

That's because Phillis wants to be called "She".

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

19. ### Phil AllisonGuest

"John Larkin"

** They are very important to communication of ideas.

** How completely autistic.

Bet JL can recite " pi " to hundreds of decimal places.

......... Phil

20. ### Phil AllisonGuest

"Bob Eld"

( snip peurile abuse)

** Another autistic prick bites the dust.

....... Phil

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