PWM + dither
PWM + dither
(OP)
The principles of PWM are clear to me, but does anyone have any pictorial representation of what dither looks like when superimposed on the PWM signal. We use these principles in the drivers for solenoids on hydraulic proportional valves.
Please direct me to a more appropriate forum if needed.
Please direct me to a more appropriate forum if needed.





RE: PWM + dither
Unfortunately your question makes little sense.
What dither? And why do you expect any dither?
What kind of system are you speculating about? If there is some dither in the output what it would look like would depend on where the dither originates.
Perhaps if you would describe more of what you are doing we can give you a valid answer.
Keith Cress
kcress - http://www.flaminsystems.com
RE: PWM + dither
The more common is to broaden the spectrum so that peaks in the EMI spectrum get lower and broader. That sometimes saves the bacon for those who didn't filter their outputs well enough.
The other use is to "vibrate" the mean value of a PWM DC signal in proportional valves and such devices so that stiction is overcome. In the latter case, the PWM duty cycle is varied with a low frequency.
Picture, see htt
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: PWM + dither
Roy
RE: PWM + dither
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John D
RE: PWM + dither
Keith Cress
kcress - http://www.flaminsystems.com
RE: PWM + dither
Your proportional valve demand is likely to exist in some other form - either digital or analog - upstream of the pulse width modulator, and to my mind, it's easier to add a simple dither signal to that rather than trying to do something clever to the pulse train (especially if you're using a pair of solenoids to drive a directional valve).
A.
RE: PWM + dither
Would you mind reposting that with a frequency of 30Hz? I'm working on a school project that requires it...
:)
Dan - Owner

http://www.Hi-TecDesigns.com
RE: PWM + dither
RE: PWM + dither
Dan - Owner

http://www.Hi-TecDesigns.com