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.

Methods and apparatus for open loop startup of a three-phase motor that reduces acoustic noise. During rotor alignment of the motor, there is a maximum level for a phase current to the motor. After the rotor alignment, open loop motor startup is performed during which the phase current has a first slope. At a selected time, such as when a frequency of the phase current reaches a first threshold, the phase current transitions to a second slope.

Methods and apparatus for open loop startup of a three-phase motor that reduces acoustic noise. During rotor alignment of the motor, there is a maximum level for a phase current to the motor. After the rotor alignment, open loop motor startup is performed during which the phase current has a first slope. At a selected time, such as when a frequency of the phase current reaches a first threshold, the phase current transitions to a second slope.

Example systems and processes control transition of an electric motor from open-loop operation to closed-loop operation by detecting zero-crossing (ZC) locations of the back-electromotive force (BEMF). The rotor angle of the electric motor is changed, e.g., by changing acceleration of the electric motor to correct a phase difference based on the detected ZC locations and an open-loop profile of the electric motor. Detected ZC locations may be used to identify ZC-detected-based commutation points, and each detected ZC location may be used to update a next commutation point. During the control process the open-loop profile is updated. Transition may occur when a set number of ZC-detection-based commutation points are sufficiently aligned with corresponding updated commutation points, or such alignment is maintained for at least one electrical cycle.

The present application provides a method for speed estimation, device, electronic device, and storage medium, and relates to the technical field of rotational speed estimation. The method for speed estimation is applied to a three-phase brushless motor: firstly, acquire voltages of three terminals of a three-phase brushless motor; secondly, take the voltage difference value of each two terminals as an equivalent line voltage; thirdly, determine a virtual Hall signal according to a zero-crossing point of the equivalent line voltage; and lastly, estimate the rotational speed of the three-phase brushless motor according to the virtual Hall signal. The method for speed estimation, device, electronic device, and storage medium provided in the present application have the advantage of being simpler for rotational speed estimation.

The present application provides a method for speed estimation, device, electronic device, and storage medium, and relates to the technical field of rotational speed estimation. The method for speed estimation is applied to a three-phase brushless motor: firstly, acquire voltages of three terminals of a three-phase brushless motor; secondly, take the voltage difference value of each two terminals as an equivalent line voltage; thirdly, determine a virtual Hall signal according to a zero-crossing point of the equivalent line voltage; and lastly, estimate the rotational speed of the three-phase brushless motor according to the virtual Hall signal. The method for speed estimation, device, electronic device, and storage medium provided in the present application have the advantage of being simpler for rotational speed estimation.

The present disclosure a program burning device configured to read or write to a program burning interface. The program burning device includes a microprocessor, a programming drive circuit and an overcurrent protection circuit. The microprocessor outputs a first test signal or a second test signal. The programming drive circuit outputs a high driving voltage or a low driving voltage to the program burning interface. After the programming drive circuit outputs the low driving voltage for a preset time, the programming drive circuit outputs the high driving voltage to make the program burning interface form a high impedance. Afterwards, the overcurrent protection circuit receives the first test signal to trigger the overcurrent protection, and then receives the second test signal to trigger the undercurrent protection. If triggering the overcurrent protection and the undercurrent protection are continuously failed over a preset number of times, the microprocessor determines that current protection is failed.

A motor unit having a motor having a stator and an armature, the armature being arranged for relative driven motion with respect to the stator. A motor control unit has a supply circuit for providing a supply voltage at the motor to provide a set power level to the motor for driving the armature into motion. A measurement circuit is measuring a value of a physical variable indicative of a current flow through the motor, The motor control unit is arranged to interrupt the provision of the supply voltage by the supply circuit and to dynamically brake the motor during a braking time interval and further to measure the value of the physical variable during the braking time interval. The motor control unit is further arranged to compare the measured value of the physical variable with a target value that depends on the supplied power level and on an intended motion amplitude of the armature, to determine a new set power level in dependence on the comparison result and to subsequently provide the new set power level to the motor.

A motor unit having a motor having a stator and an armature, the armature being arranged for relative driven motion with respect to the stator. A motor control unit has a supply circuit for providing a supply voltage at the motor to provide a set power level to the motor for driving the armature into motion. A measurement circuit is measuring a value of a physical variable indicative of a current flow through the motor, The motor control unit is arranged to interrupt the provision of the supply voltage by the supply circuit and to dynamically brake the motor during a braking time interval and further to measure the value of the physical variable during the braking time interval. The motor control unit is further arranged to compare the measured value of the physical variable with a target value that depends on the supplied power level and on an intended motion amplitude of the armature, to determine a new set power level in dependence on the comparison result and to subsequently provide the new set power level to the motor.

A method includes driving a selected motor winding to be in a tri-state during a time interval having a finite time length value of a time window, sensing a zero-crossing (ZC) of an oscillating back electromotive force induced in the motor winding during the time window in which the motor winding is in the tri-state, and producing a ZC sensing signal, which has a first edge at a first time instant at the sensed ZC and a second edge at a second time instant separated from the first time instant by a half oscillation of the oscillating back electromotive force, detecting a phase of a current flowing in the motor winding at a time instant time-shifted with respect to the second time instant of the second edge of the ZC sensing signal, and adjusting the finite time length value based on the detected phase of the current.