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Old Jan 28, 2004, 10:15 PM
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The blade numbers go up to 11
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Sydney, Australia
Joined Aug 2002
4,478 Posts
Quote:
It was very sensitive to slight shifts in the signal phase
That's the whole idea! Basically you're working out the phase angle of the signal with respect to a fixed sine wave of the same frequency.

I've found that some motors are noisy and some aren't. It also depends on the prop - or in my case the ducted fan which is a whole lot more succeptable to accoustic ringing due to low freq pwm. In serious motor controllers the DSP's use a slightly varying pwm freq to avoid any chance of audible noise.

This is a great thread, BTW!

Stu Maxwell
StumaxAircraft
stumax@hotmail.com
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