A motor drive system for use with a motor comprising a first high-side switch coupled to a high voltage bus and the motor. A first low-side switch coupled to the motor and a return, a turn ON and turn OFF of the first high-side switch and the first low-side switch provides a phase current for the motor. A system controller configured to receive a phase current sense signal representative of the phase current of the motor and configured to begin an alignment sequence to align the motor to a goal alignment position, wherein during the alignment sequence at least one of the first high-side switch or the first low-side switch is turned ON and OFF having an alignment duty ratio, and the system controller is configured to end the alignment sequence in response to a sensed decrease in the phase current sense signal or a first duration has elapsed.

A system is for a machine having an alternating current (AC) power source with a first side and a second side, one or more windings, an AC polarity detector, a Hall effect device, two or more pairs of power switches, and a motor controller. The motor controller determines which of the power switches to open or close to obtain a direction of current flow through the one or more windings based on signals from the AC polarity detector and the Hall effect device.

A motor drive control device capable of determining a drive state of a motor is provided. The motor drive control device includes a plurality of motor drive circuits performing, based on drive control signals (Sca1 and Sca2) for controlling the number of rotations of a motor, control of energization of the motor and outputting FG signals (fg1 and fg2) having a cycle corresponding to the actual number of rotations of the motor, a composite signal generation circuit receiving an input of each of the FG signals output from the motor drive circuits and generating a composite signal by combining input signals, and a drive control circuit generating, based on a speed command signal indicating a target number of rotations of the motor, the drive control signals and outputting the drive control signals to each of the motor drive circuits. The FG signals output from the motor drive circuits have a phase difference from each other.

A method of controlling a brushless permanent-magnet motor having a phase winding and a rotor, includes applying voltages of first and second opposing polarities to the phase winding when the rotor is oscillating about a parking position, measuring a plurality of first times, each first time including a time taken for current flowing through the phase winding in response to an applied voltage of the first polarity to exceed a threshold and measuring a plurality of second times, each second time including a time taken for current flowing through the phase winding in response to an applied voltage of the second polarity to exceed the threshold. The method includes determining which of an average magnitude of the plurality of first times and an average magnitude of the plurality of second times has the smaller average magnitude, and determining an amplitude peak of the plurality of times having the smaller average magnitude. The method includes using the amplitude peak to calculate a time window, setting a timer corresponding to the time window at a subsequent determined amplitude peak, and applying a drive voltage to the phase winding during the time window.

A method for starting a sensorless single-phase electric motor. The electric motor includes a permanent magnetic motor rotor, an electromagnetic motor stator having a stator coil, a power electronics which energizes the stator coil, a current sensor which measures a current flowing in the stator coil, and a control electronics which controls the power electronics. The control electronics is connected with the current sensor. The method includes energizing the stator coil with an alternating drive voltage, monitoring a drive current which is generated in the stator coil by the alternating drive voltage, and commutating the alternating drive voltage whenever the drive current reaches a predefined positive current threshold value or a predefined negative current threshold value.

A method and an apparatus may detect a rotor magnetic pole of a single-phase BLDC motor. The method and apparatus may quickly and precisely initially drive the single-phase BLDC motor by detecting a position of a magnetic pole of a rotor adjacent to a stator by applying a high frequency voltage to the single-phase BLDC motor and analyzing a magnitude of a flowing current.

A system is for a machine having an alternating current (AC) power source with a first side and a second side, one or more windings, an AC polarity detector, a Hall effect device, two or more pairs of power switches, and a motor controller. The motor controller determines which of the power switches to open or close to obtain a direction of current flow through the one or more windings based on signals from the AC polarity detector and the Hall effect device.

An electrical device includes a brushless one-phase driving motor which drives a mechanical unit. The brushless one-phase driving motor includes a motor rotor which is radially permanently magnetized and which rotates around a rotational rotor axis, a non-symmetric stator back-iron structure which includes a rotor opening for the motor rotor and a lateral bridge portion which magnetically connect two stator poles, a single stator coil which surrounds the lateral bridge portion, a pole separation gap arranged radially opposite to the lateral bridge portion, the pole separation gap magnetically separating the two stator poles, an electronic control device which drives the single stator coil, and a single hall sensor which is electrically connected to the electronic control device. The single hall sensor is arranged approximately radially opposite to the single stator coil with respect to the rotational rotor axis.

A method is for a machine having an alternating current (AC) power source with a first side (L1) and a second side (L2), two or more pairs of power switches, and one or more windings. The method comprises closing one pair of power switches by a control circuit to cause current to flow from a first side of the AC power source, through the one or more windings, and to the second side of the AC power source and closing another pair of power switches by the control circuit to cause current to flow from the second side of the AC power source, through the one or more windings, and to the first side of the AC power source.

A method and an apparatus may detect a rotor magnetic pole of a single-phase BLDC motor. The method and apparatus may quickly and precisely initially drive the single-phase BLDC motor by detecting a position of a magnetic pole of a rotor adjacent to a stator by applying a high frequency voltage to the single-phase BLDC motor and analyzing a magnitude of a flowing current.