Quote:
Originally Posted by theokie
Mike,
I was unsure if a PWM sine wave was square or a bit closer to a true wave form, but it appears, I'm just going to have to bite the bullet or rather cut in to my coral budget for the next month or two.
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Yeah, I've never heard a manufacturer of inverters use the term PWM sine wave. I know that the cheaper inverters with 'modified' sine waves have 'chopped' peaks, so not really a true square wave either, as they try to time a bit of a slope into the wave to make it more sinusoidal. To me PWM can mean many things, including a modified square wave with different frequency and all kinds of nasty permutations. In other words, not only can the amplitude of the wave vary from one wave to another, but also the 'off' time between waves, i.e. the width between pulses, which is a sort of frequency modulation. I would hope that something PWM designed to emulate an AC sine wave would very closely mimic such sine wave, but it's still not a pure sine wave, so probably not the best option to run an AC motor. I could be wrong & they've figured out how to time the pulses to make a pure sine wave, who knows. More research required....