Abstract: A microcontroller controls a BLDC motor with Hall sensors. In a calibration mode, the microcontroller operates the motor at substantially constant load and speed. A first current value across the motor is detected. A reference phase angle value is adjusted and a second current value is detected. If the second current value is less than the first current value, then the reference phase angle value is adjusted and a next current value is detected. The adjusting and detecting is repeated until the next current value is greater than the previous current value indicating that the adjustment increased current across the motor. The adjusted reference phase angle value before increased motor current is stored. In a normal operating mode, using the adjusted reference phase angle value results in desired motor operation where minimal current is consumed for a given load and speed despite asymmetries in motor windings and Hall sensor placement.

Abstract: A microcontroller controls a BLDC motor with Hall sensors. In a calibration mode, the microcontroller operates the motor at substantially constant load and speed. A first current value across the motor is detected. A reference phase angle value is adjusted and a second current value is detected. If the second current value is less than the first current value, then the reference phase angle value is adjusted and a next current value is detected. The adjusting and detecting is repeated until the next current value is greater than the previous current value indicating that the adjustment increased current across the motor. The adjusted reference phase angle value before increased motor current is stored. In a normal operating mode, using the adjusted reference phase angle value results in desired motor operation where minimal current is consumed for a given load and speed despite asymmetries in motor windings and Hall sensor placement.