When sound wave is converted into electrical wave, is the electrical wave a sinusoidal with constant frequency and amplitude ?
But why then everyone else draws this signal as constant while describing modulation ?Only if you are a good whistler. Connect a mic to a scope and watch. The electric "wave" follows the frequency and amplitude of the sound wave.
Yes, it doesBecause it's easier to see, and understand. Also unlike our voice, our test generators use nice sine waves. Our voice waves change too fast for our eyes to see. But if we use a symmetrical sound pattern.......it's easier to use and measure.
Does that make sense?
AaaaaA diode does not destroy a signal. It rectifies it. It cuts it in half and only allows one side to pass. It will select either the positive part or the negative part. The positive part is a mirror of the negative part.......and vice-a-versa. They are mirrors. They are equal.....just inverted. SO.......we only need one. This would be called half wave rectification.
But if we use more than one diode........we can flip the half that was discarded........and add it to the one we saved.
That's called full wave rectification.
Thanks a lot then !When we listen to audio.......our brain does not listen to every little component of the sound. Our brain detects the average amplitude and average frequency. It listens and detects the envelope (average) of the sound. Our brain catalogs envelopes. These envelopes are patterns. This is why we can understand a word that comes from different people. The individual sound is different.......but the pattern is the same.........or close to it.
No, it will vary in frequency and amplitude.When sound wave is converted into electrical wave, is the electrical wave a sinusoidal with constant frequency and amplitude ?
Everyone does not do this. A carrier maintains it's frequency, but the envelope reproduces the audio modulating signal.But why then everyone else draws this signal as constant while describing modulation ?
The modulating signal does the same thing to the positive half cycle as the negative have cycle. They are mirror images of each other.Yes, it does
But if the picture that we see in the oscilloscope represents our real voice, how will the diode cut off bottom part of the signal without destroying it >
It is true for an AM modulated signal, which is what they are referring to.Both BR-549 and Papabravo have said "The positive and negative half cycles are mirror images of each other". Whilst I understand why they have said this, and whilst it makes it easier to explain the basic case to the OP, it's not actually true!
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