PWM problem (phase diffrence between Pwm1 and Pwm2 )

Started by bacha bacha March 4, 2004
Hi, I have used 18f452 to generate pwm but i havent
acchived 180 degree phase difference. (Pwm1 and Pwm2
were generated at the same time.) can any body help me
to do that with pics? Or do you know another way? For
example, DSP (30Fs, ADMC401, etc.)

******please open the attachement first. ****

Thanks alot

__________________________________

Attachment (not stored)
bacha.zip
Type: application/x-zip-compressed


Both PWMs are set by a match of Timer2 to PR2, therefore they are both
set at the same time, they are always in sync on the rising edge. You
can not do what you want, unless you invert one of the outputs.

I assume this is what you want, I can not open your attachment easily,
I think it may be in Word.

Chad

--- bacha bacha <> wrote:
> Hi, > I have used 18f452 to generate pwm but i havent
> acchived 180 degree phase difference. (Pwm1 and Pwm2
> were generated at the same time.) can any body help me
> to do that with pics? Or do you know another way? For
> example, DSP (30Fs, ADMC401, etc.)
>
> ******please open the attachement first. ****
>
> Thanks alot
>

=====
My software has no bugs. Only undocumented features.

__________________________________




Thanks Chad,
I have attached the file(word) again. My pwm period
and duty cycle will change(+ or -) simultanously
according to the feedback. if i invert pwm2,
automaticaly duty cycle will be equal dead time, will
not? So my IGBT circuit(for induction heating) don't
allow me to that. there must be a way(i hope).

Thank you...
Bacha

--- Chad Russel <> wrote:
> Both PWMs are set by a match of Timer2 to PR2,
> therefore they are both
> set at the same time, they are always in sync on the
> rising edge. You
> can not do what you want, unless you invert one of
> the outputs.
>
> I assume this is what you want, I can not open your
> attachment easily,
> I think it may be in Word.
>
> Chad
>
> --- bacha bacha <> wrote:
> > Hi,
> >
> >
> > I have used 18f452 to generate pwm but i havent
> > acchived 180 degree phase difference. (Pwm1 and
> Pwm2
> > were generated at the same time.) can any body
> help me
> > to do that with pics? Or do you know another way?
> For
> > example, DSP (30Fs, ADMC401, etc.)
> >
> > ******please open the attachement first. ****
> >
> > Thanks alot
> >
>
> =====
> My software has no bugs. Only undocumented
> features.
>
> __________________________________ > to unsubscribe, go to http://www.yahoogroups.com and
> follow the instructions
> Yahoo! Groups Links >


__________________________________

Attachment (not stored)
bacha.zip
Type: application/x-zip-compressed


Ok, I imported it to Word Perfect. Do you need to vary PWM1 and PWM2
independently? If yes, then you need enabling logic, if no, you can
use just one output with steering logic.

You can used another output pin to enable or steer, or you can use a
separate flip-flop. Let me know if you would like some kind of
schematic.

Chad

--- bacha bacha <> wrote:
> Thanks Chad,
> I have attached the file(word) again. My pwm period
> and duty cycle will change(+ or -) simultanously
> according to the feedback. if i invert pwm2,
> automaticaly duty cycle will be equal dead time, will
> not? So my IGBT circuit(for induction heating) don't
> allow me to that. there must be a way(i hope).
>
> Thank you...
> Bacha
>
> --- Chad Russel <> wrote:
> > Both PWMs are set by a match of Timer2 to PR2,
> > therefore they are both
> > set at the same time, they are always in sync on the
> > rising edge. You
> > can not do what you want, unless you invert one of
> > the outputs.
> >
> > I assume this is what you want, I can not open your
> > attachment easily,
> > I think it may be in Word.
> >
> > Chad
> >
> > --- bacha bacha <> wrote:
> > > Hi,
> > >
> > >
> > > I have used 18f452 to generate pwm but i havent
> > > acchived 180 degree phase difference. (Pwm1 and
> > Pwm2
> > > were generated at the same time.) can any body
> > help me
> > > to do that with pics? Or do you know another way?
> > For
> > > example, DSP (30Fs, ADMC401, etc.)
> > >
> > > ******please open the attachement first. ****
> > >
> > > Thanks alot
> > >
> >
> >
> >
> >
> > =====
> > My software has no bugs. Only undocumented
> > features.
> >
> > __________________________________
> >
> >
> > to unsubscribe, go to http://www.yahoogroups.com and
> > follow the instructions
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> > __________________________________
>
> ATTACHMENT part 2 application/x-zip-compressed namecha.zip
=====
My software has no bugs. Only undocumented features.

__________________________________