J
John Larkin
- Jan 1, 1970
- 0
You use the plain old sines and cosines.
Works like a champ.
Works exactly like an FFT. Same windowing artifacts, same aliasing,
same math.
John
You use the plain old sines and cosines.
Works like a champ.
If you have anything sensible to say, then say it. *IF*
On Thu, 31 May 2007 16:13:49 GMT, "Thomas Magma"
Actually, it will. If you strike it gently at a rate that's an integer
fraction of a major resonance, that resonance will build up in
amplitude over multiple strikes, much more than if the ratio is not
maintained. Of course, thet's not easy to do by hand; the frequency
and phasing have to be exact.
The bell is a bandpass filter.
Not even wrong.
A resonant system is a resonant system.
Response depends on both the forcing function (transient) and the
natural function (steady state).
MooseFET said:In the case of the bell, the bell selects the frequencies near its
resonance from the input. If the input is a repeated waveform such as
striking at a constant rate, this input only has harmonics of the
stike rate in it. Since the bell can't create new frequencies, it
must select from those harmonics.
Best answer yet. It makes good sense.
It's now buggered me all up philosophically when thinking of a 1nS, 0
to 5V pulse, occuring once a week and the physical nature of some kind
of 'continuum' where the harmonics are spending their time oscillating
and cancelling each other out. ( from Monday through to Saturday ;-)
Electronics is amazing!.
Thomas said:Hello,
I'm trying to determine if the higher harmonics of a low frequency square
wave are actually AM modulated. For instance, I can see the harmonics of a 1
KHz square wave all the way up at 100 MHz if I zoom into them on a spectrum
analyzer. Are those harmonics really there when the 1 KHz square wave has
finished it's transition and is in a steady state for half a millisecond?
If I was to sample this steady state with a ultra fast ADC and FFT the samples,
would I see the harmonics extending up through 100 MHz?
It's a bit of a mind bender when converting between the time and frequency
domain in the case of a square wave.
Not even wrong.
The response is the convolution of the forcing function against the
natural one.
Not even wrong.
The response is the convolution of the forcing function against the
natural one.
Works exactly like an FFT. Same windowing artifacts, same aliasing,
same math.
Not if it's an oscillator, and not if it's nonlinear. A pipe organ is
both.
John
Uh? You're tip-toeing thru the tulips there, John. In an oscillator
the forcing function IS the oscillator non-linearity.
Don't get me started on Lyopanov ;-)
It occurs to me that if the square wave were actually created with aNote that if a 1 kHz square wave were generated with a trillion sine wave
generators in series, on a scope it would look the same as if it had been
generated with a flip-flop. And a circuit driven with it would behave
exactly the same as if it came from a flip-flop. In this case, there would
be *actual* sine waves adding up to form the square wave.
It occurs to me that if the square wave were actually created with a
bunch of sine wave generators in a black box, with only the final waveform
available at the terminals of the box (in this case, though, we're allow to
look inside), we could be having the argument in reverse.
Some might say, "No, there isn't a actual square wave present; it's just
a mathematical abstraction."
They would be correct since you can never truly make a squarewave.
The rise time is never zero.
And you can never truly make a sinewave; the distortion is never zero.
There's always something to quibble about, isn't there?
No, there isn't always something to quibble about.
You're quibbling about whether there's always something to quibble about?
Sheeesh!! (as Winfield might say)
MooseFET said:Allow me to point out the smily at the end of the line. It was
intended as a joke.