Sine wave frequency 2

I think what you are asking is:

Start with some sine wave at arbitrary v = ASinw(1)t and vary the frequency to some new signal v = ASinw(2)t.

Is that correct?

You are then asking, if one does this, will the result still be a sine wave?

Is that also correct?

At all instantaneous points (time) during the transition, you will have a single sine wave, assuming you are simply changing the frequency of a single source.

Cheers

PeteS

A sine wave may be any frequency you wish - from one cycle per week or more, up to Gigahertz.

It's not dreadfully clear what you are asking; though if I asked a question in wg=hatever is your native language (Greek?) I doubt if it would make any sense at all.

This is an answer to what I think is your question.

A sine wave is defined as a voltage/ frequency/ whatever which varies as a function of time such that the instantaneous value V = Vm sin wt. Vm is the peak absolute value, w is 2*pi*frequency, and t is time.

Obviously, any deviation from that relationship makes it, strictly speaking, not a sinewave. The deviation could be noise, distortion, maximum amplitude variation, frequency variation etc. A Fourier analyser attached to the signal would show these up as the base level, harmonics etc. as well as the pure single fundamental of a sinewave.

You are talking of a signal which can be expressed as V = Vm sin w(t) t, where w(t) is itself a function of time- in your case, I think, a ramp. You can plug that function into the Fourier calculation, do the sums and come up with the answer, for any function of time that you choose.

But we are a bit lax, and basically if it LOOKS like a sinusoidy squiggle on the scope, we call it a sine wave. Most of the time, everybody understands, or don't care anyway.

Now, why do you need to know?

Paul Burke

I think you might be asking about frequency modulation. If you are, the result is a group of sine and cosine functions (frequencies) that can be predicted with Bessel functions.

I am guessing what you are trying to say. Possibly you want to vary the frequency of a Sine wave oscillator you have designed or have. Your question is by simply changing a component value or 2 do I still have a Sine Wave? If you are using an Analog oscillator I'd think No. Don't believe what the books say it won't work so easily . You have to redesign the whole thing. With a digital oscillator ... Yes very likely.

If your question is about Sine wave purity ... Yes it can be compromised by changing the frequency. It all depends on the details on what you are using to generate the thing.

"Go easy on the whisky"

theJackal

I understood well, I've just been reading your thread waiting for someone else to get it. :-)

A sine wave can be at any frequency, and still be a sine wave. The term "sine wave" just defines the _shape_ of the wave, but the wave can be at any frequency you wish. (well, within limits, of course).

If you put a small pen sticking out the bottom of a pendulum bob, and drag a piece of paper under it at a constant speed, it will draw a sine wave.

And someone else has already typed the trig expression, which boils down to y = sin x. :-)

Hope This Helps! Rich

LMAO Phil you are too repetitious.

But better die than live mechanically a life that is a repetition of repetitions. D. H. Lawrence

"Go easy on the whisky"

theJackal

"theJackal"

"theJackass"

Must be posting straight from an asylum for the criminally insane.

...... Phil

"theJackal" "theJackass"

Likely posting direct from an asylum for the criminally insane.

His comments are all plagiarised from Google.

Would almost be funny - if he was not so dangerous.

........ Phil