[PD] Re: [PD-announce] PWM in Pd

Hans-Christoph Steiner hans at eds.org
Thu May 25 19:04:53 CEST 2006

On May 25, 2006, at 5:47 PM, Frank Barknecht wrote:

> Hallo,
> Hans-Christoph Steiner hat gesagt: // Hans-Christoph Steiner wrote:
>> Ah yes, [pwm~] is using zexy's [>~].  I was looking at [pwm].  That
>> example (I am looking at K01.pulse.width.mod.pd from 0.38.4) is very
>> simple, but as it is, it is not usable.  Notice how the LOW and HIGH
>> change values.  PWM needs be 0 for LOW and 1 for HIGH.  That example
>> is usable in an audio context, since DC offset doesn't really
>> matter.  I guess you could rely on the DAC in the soundcard to remove
>> the DC, but that is probably asking for trouble.
> Well, the phasor-substraction is the classical analog synth pwm, where
> you can do pwm with substracting two sawtooth waves. It is limited
> because of the DC wandering, but it works quite okay for sound.
> Attached is your patch where I replaced the zexy object with a crude
> waveshaper. I also replaced the phase-inlet with a frequency inlet,
> because I think, this is more useful to have than an inlet to reset
> the phase. Of course both inlets would be useful in the end.
> Attached patch is more a proof of concept and not recommended for real
> use.

I should say, I forgot that PWM was used in synthesis some, so I was  
thinking about electronics and control when I was talking about PWM.   
That's why my PWM objects are tailored towards, but should work fine  
in the audio context too, unless you need the wandering DC offset.



                     There is no way to peace, peace is the way.
						        				-A.J. Muste

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