carrier frequency and output frequency
carrier frequency and output frequency
(OP)
What must be the relationship with the carrier signal and modulator(output) signal. I mean at least what must be the ratio between them? Can i get a 1KHz spwm signal with 7KHz carrier signal?






RE: carrier frequency and output frequency
It is almost like the Nyquist frequency - but reverse. If your motor inductance filters the carrier frequency very well, then you can go close to motor frequency = 1/2 carrier frequency. At least in theory. And with the motor acting as a brick-wall filter.
But since the motor is a first order low pass filter (6 db/octave) it will not work. You will probably need something like carrier = 10 times motor frequency or better.
1000 Hz motor frequency at 7 kHz carrier is doable, but be prepared to have some interference between carrier and motor frequencies. An output filter could perhaps improve the situation.
Gunnar Englund
www.gke.org
RE: carrier frequency and output frequency
Asynchronous modulation usually require ratios of at least 20.
RE: carrier frequency and output frequency
RE: carrier frequency and output frequency
Gunnar Englund
www.gke.org