Hall devices measure the presence of a magnetic field and are used in 3 phase brushless motors to commutate the motor. Commutation is the process of applying the correct current into each motor phase to produce torque. Upon power-up of a motion system, the Hall sensors measure the position of rotator with respect to the stator, and current can be applied to the motor to begin motion without any initialization routine.
For more information on Hall Sensors and other types of position sensors click here.
