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Andy Wander
Of course, by changing the width of the ON pulkse, while the frequency stays
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the same, the width of the OFF pulse is changed also, in the opposite direction. For example a 50% PWM pulse train will look just like a square wave at that frequency, because the ON pulse will be 50" of the period, and so will the OFF pulse. A 20% PWM will have the ON time at 20" of the period, and the OFF at 80%. Etc.. Andy Wander Verrex Corporation -----Original Message-----
From: Andy Wander [mailto:awander@...] Sent: Monday, March 01, 2004 12:40 PM To: 'mach1mach2cnc@...' Subject: RE: [mach1mach2cnc] Re: Question on index pulse I can't speak about the intricacies of the VFD, but PWM is Pulse Width Modulation, where the ONLY thing that is varied is the width of the "ON" pulse(not both ON and OFF). This means that the frequency of the pulses does NOT change, just the ratio of ON-time to OFF time of a (quasi) square wave. If the width of both the ON and the OFF pulse changed(and was identical, you would NOT have PWM, you would have FM(frequency modulation) of a square wave. Andy Wander Verrex Corporation -----Original Message----- From: washcomp [mailto:jeff@...] Sent: Monday, March 01, 2004 12:36 PM To: mach1mach2cnc@... Subject: [mach1mach2cnc] Re: Question on index pulse Unless I'm mistaken, (wouldn't be the first time), the way the frequency variation manifests itself is by modulating the pulse width. Pulses shorter and closer together = higher frequency. Please correct me if I'm wrong. Jeff --- In mach1mach2cnc@..., Andy Wander <awander@v...> wrote: Of course, VFD means Variable Frequency, so is this actually a PWMsignal? I'm so confused...VFD be used for this? If so, can it be scaled in MACH2 to correspnd tothe numeric value of one will not be the same as the other.<> > M=274551.4550177.5761904.1261774/D=egroupweb /S=:HM/A=2019528/rand=446470174><> < <> > <<> < <> > > subject=Unsubscribe> of < <> <<> > > Service. _____ Yahoo! Groups Links * To visit your group on the web, go to: <> < <> > * To unsubscribe from this group, send an email to: mach1mach2cnc-unsubscribe@... <mailto:mach1mach2cnc-unsubscribe@...?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of < <> > Service. Yahoo! Groups Sponsor ADVERTISEMENT Click HereClick Here < /S=:HM/A=2019528/rand=704545992> _____ Yahoo! Groups Links * To visit your group on the web, go to: <> * To unsubscribe from this group, send an email to: mach1mach2cnc-unsubscribe@... <mailto:mach1mach2cnc-unsubscribe@...?subject=Unsubscribe> * Your use of Yahoo! Groups is subject to the Yahoo! Terms of <> Service. |
