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What's_nitro? · 11:31 PM

Ripple itself isn't actually feedback. It can cause feedback, and that feedback can damage components.

So a BL motor has 3 phases... Every time a phase is sent power by the ESC a high load is placed on the battery. If the battery has trouble supplying the current that the motor phase wants, the voltage at the battery drops for a split second while that phase gets power. Just before the next phase of the motor recieves power, the voltage at the battery jumps back up. Rinse. Repeat. Imagine this happening at 3000 Hz, as it would inside a 2-pole motor revving at 30K rpm. You basically have an AC waveform being fed to the ESC that wants DC power. Bad stuff...if the ripple amplitude is high enough.

I'm not sure what an acceptabe value would be for the MMM... Maybe Patrick will answer that one.

	(#5)
What's_nitro? Soldermaster Extraordinaire Offline Posts: 4,529 Join Date: Apr 2007 Location: Plymouth, MA, USA	01.14.2011, 11:29 PM Ripple itself isn't actually feedback. It can cause feedback, and that feedback can damage components. So a BL motor has 3 phases... Every time a phase is sent power by the ESC a high load is placed on the battery. If the battery has trouble supplying the current that the motor phase wants, the voltage at the battery drops for a split second while that phase gets power. Just before the next phase of the motor recieves power, the voltage at the battery jumps back up. Rinse. Repeat. Imagine this happening at 3000 Hz, as it would inside a 2-pole motor revving at 30K rpm. You basically have an AC waveform being fed to the ESC that wants DC power. Bad stuff...if the ripple amplitude is high enough. I'm not sure what an acceptabe value would be for the MMM... Maybe Patrick will answer that one. Last edited by What's_nitro?; 01.14.2011 at 11:31 PM.