Abstract: A motor is coupled to a motor control device including a set of high-side switches, a set of low-side switches, a capacitor and a controller. The set of high-side switches and the set of low-side switches are coupled to the motor. The capacitor is coupled to the set of high-side switches. The controller is coupled to the capacitor, the set of high-side switches and the set of low-side switches. A method of braking the motor includes upon the motor being disconnected from an external power source, the controller receiving a supply voltage from the capacitor, turning on the set of low-side switches, turning off the set of high-side switches, and the controller switching the set of low-side switches according to the supply voltage.

Abstract: A motor system includes a brushless direct current motor, a back electromotive force (EMF) circuit, and a control unit. The brushless direct current motor includes first to third windings. The back EMF circuit is coupled to the first to the third windings. The control unit is coupled to the back EMF circuit for floating the first winding, energizing the second winding, and energizing the third winding prior to detect a zero-crossing event. The back EMF detects a duration of a freewheeling period of a back EMF signal of the first winding and a zero-crossing event. The control unit updates respective initial angles of respective driving currents of the first to the third windings according to the duration of a freewheeling period, and performs commutation according to respective updated initial angles of the respective driving currents of the first to the third windings upon detecting the zero-crossing event.

Abstract: A motor system includes a brushless direct current motor, a back electromotive force (EMF) circuit, and a control unit. The brushless direct current motor includes first to third windings. The back EMF circuit is coupled to the first to the third windings. The control unit is coupled to the back EMF circuit for floating the first winding, energizing the second winding, and energizing the third winding prior to detect a zero-crossing event. The back EMF detects a duration of a freewheeling period of a back EMF signal of the first winding and a zero-crossing event. The control unit updates respective initial angles of respective driving currents of the first to the third windings according to the duration of a freewheeling period, and performs commutation according to respective updated initial angles of the respective driving currents of the first to the third windings upon detecting the zero-crossing event.

Abstract: A motor is coupled to a motor control device including a set of high-side switches, a set of low-side switches, a capacitor and a controller. The set of high-side switches and the set of low-side switches are coupled to the motor. The capacitor is coupled to the set of high-side switches. The controller is coupled to the capacitor, the set of high-side switches and the set of low-side switches. A method of braking the motor includes upon the motor being disconnected from an external power source, the controller receiving a supply voltage from the capacitor, turning on the set of low-side switches, turning off the set of high-side switches, and the controller switching the set of low-side switches according to the supply voltage.