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BrianG · 06.12.2007, 01:12 AM

I still don't think the feedback pulses are perfect sine waves. You are applying a high current square wave signal to a coil. When the field collapses, it will generate a back-EMF spike. However, since this is happening kinda fast, the spikes aren't as bad as they normally would be. It probably looks more like a semi-sinusoidal pulse with a little decay before the next pulse from the ESC comes in.

Now, if we were talking about variable frequency sine-wave drives, then yes, the feedback would be a perfect sine wave. Man, I wish I still had access to a o-scope to check this!

	(#22)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	06.12.2007, 01:12 AM I still don't think the feedback pulses are perfect sine waves. You are applying a high current square wave signal to a coil. When the field collapses, it will generate a back-EMF spike. However, since this is happening kinda fast, the spikes aren't as bad as they normally would be. It probably looks more like a semi-sinusoidal pulse with a little decay before the next pulse from the ESC comes in. Now, if we were talking about variable frequency sine-wave drives, then yes, the feedback would be a perfect sine wave. Man, I wish I still had access to a o-scope to check this!