i need someone to explain for me wh

[tony231]

i need someone to explain for me why PWM modulation its pulse duration modulation and the time of the PWM signal is constant but the width is variable
and the time in PPM signal is variable because the pulse changing its position

 

[IRstuff]

I'm not sure what you're asking, since PWM stands for Pulse Width Modulation, and PPM stands for Pulse Position Modulation, so the waveforms behave as their names suggest.

For more information, I suggest you read Wikipedia's entriesL

https://en.wikipedia.org/wiki/Pulse-width_modulation

https://en.wikipedia.org/wiki/Pulse-position_modulation

TTFN (ta ta for now)
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[Comcokid]

Notice from the examples you provided, PWM has a rising edge at the start of the clock period. To properly get the information from the PPM of your example, you need a independent clock signal or need to re-create the clock using a phase-lock-loop circuit.

Pulse Duration Modulation is a term that isn't used much. PDM has pulses of several fixed widths that are used to define the information. Morse code is an example of PDM.

 

[tony231]

in ppm if you measure the frequency it will be variable

 

[MacGyverS2000]

The immediate frequency, yes... but the average frequency will remain the same.

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