I’ve implemented simplest sensorless BLDC startup algorithm:
- Set rotor to initial position (rotor may turn in the opposite to desire direction).
- Start open loop switching.
- Start close loop switching.
It has some disadvantages and these days I’ve been tested a rotor initial position detection method. When it’s detected rotation starts in right direction.
I’ll publish all schematics and a lot of firmware code and algorithms descriptions (no math here and explanations will be very simple).