Quote:
Originally Posted by BrianG
Getting back on topic; anyone know this?
What is the "rule of thumb" regarding the minimum rpm a sensorless motor has to turn for the ESC to get the proper back-EMF signals? Something like kv * 0.1?
I want to try to include this calculation in my top speed estimator to notify the user that they are geared too high for proper ESC operation...
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A simple rule is zero-crossing.
Zero crossing would be sync with every pole, so for given motor number of magnet poles and armature poles per rotation would tell you what min. RPM would be sufficient for ESC to get it going. But to get direction correct you might want to get one extra, but it can be much simpler as well. If hardware can do that, than software is your limiting factor...