NOPE.... it is NOT physically comprised of sinusoids. The waveform can mathematically be 'expressed' as a bunch of sinusoidal waveforms. It does NOT mean that the physical waveform itself (in this case, the PWM waveform coming out of an arduino) IS a bunch of physical sinusoidal signals (plus a DC value). The sinusoids you're talking about come from the realms of mathematical modelling.
Although, 'hypothetically'...... if we had the time to do it.... you could physically generate a bunch of sinusoids at the suitable frequencies (together with suitable amplitudes) ...... and add them up..... to come up with an "approximation" for the time waveform.In the lab, you're not going to be able to generate an infinite number of harmonics. It's like e^(-t)..... it never goes to 'zero' until time reaches infinity.....and infinity means you'll never get there....because it keeps going ....forever.
but you can't deny that the physical signal can still be analyzed and broken down into an infinite sum of sinusoids
I'm not saying that the PWM signal is generated from the Arduino is an infinite number of sinusoidal voltage sources in series (quite absurd isn't it lol)
Fourier works. There's no point to arguing if it's "really real" when it's a distinction without a difference.
IMO, saying that harmonics have a "physical" property really distorts the issue to the non-EE
If I understand your argument, you just invalided it, all in the same sentence.
Valid point, it does take a while to get comfortable thinking in the frequency domain vs the time domain.
I appreciate the input but bear in mind my math/science is mid high school level (work in progress). I'm having great deal of trouble understanding how a signal that is 490Hz has a DC component and this occurs at 0Hz.When is the signal 0Hz? Are we simply taking a snapshot of the PWM signal when it is high (5V)? If this is the case then the capacitive reactance will be infinite? I feel I'm missing some key concept. @septillionI don't understand what a pure sine wave is?
y(t) = sin(t)
I don't understand what a pure sine wave is?
I don't understand what the pros/cons of adjusting the frequency?
I'm wanting to generate an analog voltage for an On Screen Display.
So? Everything in every engineering discipline involves approximate mathematical models.
It isn't 'physically' a sum of those things. Because.... physically, the physical signal in the time domain is 'The time domain Signal'.... which ...in this case.... is a periodic 2-level waveform (when the input is held at a constant value that is). Not 'physically' a bunch of sinusoids (plus a DC shift, if there is one).
So a pure sine wave is a graphed unit circle?
Increasing frequency has the following benefits. It allows us to decrease the the values of our RC circuit thus reducing size, improved responsiveness and less ripple?
The DC component is the average of the duty cycle? I'm still having trouble understanding why then we set our cut-off frequency to 0Hz?
Don't we need the voltage to toggle between 0V and 5V in order to achieve PWM?
On Screen Display (OSD)
I'm beginning to wonder whether the article that I linked to in my first post is not appropriate for my application. It deals primarily with AC signal while what I'm really interested in is a pulsed DC signal? I found the following article...
Arduino's AnalogWrite - Converting PWM to a Voltage