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BLDC motor - initial rotor position

Sensorless BLDC motor controller are becoming more and more popular, especially with rising of the drone industry. 

Being able to detect where the rotor is at 0rpm or no load seems intuitive if we have hall sensors or resolver. 

However, what I am having difficulties understanding is how do you know which phase switching combination you should start with if you don’t know where the rotor is? Do you just loop through 6 combinations and check which one would get you enough BEMF?

Is there a clever way how to do it and/or is the approach above how it’s usually done?