A motor controller comprises a switch circuit and a control unit. The switch circuit is coupled to a motor for driving the motor. The control unit is configured to generate a plurality of control signals to control the switch circuit. The motor controller utilizes a duty cycle conversion mechanism, such that the motor controller is operated in a constant voltage driving mode or a constant current driving mode. The motor controller is configured to avoid generating switching noise by the constant voltage driving mode or the constant current driving mode. The motor controller is configured to increase a success rate of starting the motor.

A method for determining zero crossing occurrence in an alternating current (AC) signal with constant frequency of a permanent magnet synchronous motor (PMSM) includes: sampling the AC signal to obtain a plurality of data points; starting to count a number of consecutive data points that have sampled values with a same sign in a detection range, to generate a count value, wherein the consecutive data points are included in the plurality of data points; determining whether the count value is equal to a zero crossing determination value; and in response to the count value being equal to the zero crossing determination value, determining that a zero crossing occurs at a last data point of the consecutive data points.

A method for determining zero crossing occurrence in an alternating current (AC) signal with constant frequency of a permanent magnet synchronous motor (PMSM) includes: sampling the AC signal to obtain a plurality of data points; starting to count a number of consecutive data points that have sampled values with a same sign in a detection range, to generate a count value, wherein the consecutive data points are included in the plurality of data points; determining whether the count value is equal to a zero crossing determination value; and in response to the count value being equal to the zero crossing determination value, determining that a zero crossing occurs at a last data point of the consecutive data points.

A control chip, a control system, and a control method for a motor are disclosed. The control chip comprises: an analog comparator comprising a first input terminal and a second input terminal, wherein the first input terminal receives a reference voltage of the motor, the second input terminal receives at least one back EMF (Electromotive Force) of the motor in turn, the analog comparator compares each of the at least one back EMF with the reference voltage in turn through a polling method, so as to produce at least one comparison result and control the motor according to the at least one comparison result. Thereby, the analog comparator is able to compare back EMF with the reference voltage without three comparators, and the cost is therefore saved.

A control chip, a control system, and a control method for a motor are disclosed. The control chip comprises: an analog comparator comprising a first input terminal and a second input terminal, wherein the first input terminal receives a reference voltage of the motor, the second input terminal receives at least one back EMF (Electromotive Force) of the motor in turn, the analog comparator compares each of the at least one back EMF with the reference voltage in turn through a polling method, so as to produce at least one comparison result and control the motor according to the at least one comparison result. Thereby, the analog comparator is able to compare back EMF with the reference voltage without three comparators, and the cost is therefore saved.

A circuit for controlling a motor that includes control circuitry configured to determine whether a commutation event has occurred for a first sector of a plurality of sectors of a cycle for the motor based on a first selected phase current signal and a second selected phase current signal. In response to a determination that the commutation event has occurred for the first sector, the control circuitry is configured to determine that the motor is operating in a second sector of the plurality of sectors of the cycle for the motor. The control circuitry is further configured to determine a second angle of stator voltage vector for the motor based on the determination that the motor is operating in the second sector and generate the control signal based on the second angle of stator voltage vector for the motor.

A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

A motor control apparatus, including: a current detection unit configured to detect a current flowing through a coil of a motor; a voltage application unit configured to apply a voltage to the coil; and a control unit configured to control the voltage application unit by outputting a PWM signal in order to rotate the motor at a predetermined rotation speed, wherein the control unit detects a rotation state of the motor based on a duty of the PWM signal and a current value detected by the current detection unit.

The present disclosure provides systems and methods for using a linear resonant actuator (“LRA”) to determine a type of contact between a device and its surroundings. The LRA may be coupled to an amplifier by one or more switches. The audio amplifier may receive a signal from a microcontroller and transmit the signal the LRA when the switches are closed. When the switches are in an open position, the LRA may be actively sensing for the type of contact. The back EMF may be measured when the switches are open. The measured back EMF waveform may be used to determine the type of contact. When the signal is not being transmitted, the LRA may be passively sensing to determine whether the device was tapped.

A BLDC motor driver circuit includes: a driving power stage circuit configured to provide a start-up test signal in a start-up mode to excite a BLDC motor, to drive a rotor of the BLDC motor to rotate for a test; a current unidirectional circuit coupled to the BLDC motor at a reverse end for detecting a BEMF, to generate a detection signal at a forward end of the current unidirectional circuit, wherein when a voltage at the reverse end exceeds a voltage at the forward end, the current unidirectional circuit limits the voltage at the forward end not to be higher than a clamp voltage; a biasing circuit for biasing the current unidirectional circuit in a forward operation state and for providing the clamp voltage; and a sensor circuit for generating a sensing signal according to the detection signal to indicate a test rotation state of the BLDC motor.