A phase control circuit for a brushless motor includes a signal output unit that outputs M signals, whose phases differ from each other, in response to a change in the magnetic field resulting from the rotation of magnets placed in a rotor, and a control signal generator that generates two or more different kinds of group of phase control signals, based on at least the M signals, the group of phase control signals being used to control drive voltages, whose phases differ from each other, which are supplied to each phase of an N-phase coil (N being an integer greater than or equal to two). The control signal generator is configured such that a first phase control signal group and a second phase control signal group can be generated.

A motor drive controller includes: a motor driver that applies a voltage to each phase of a motor to rotate; a rotational position detector that detects rotational position of the motor and generates rotational position information indicating the rotational position; and a controller that outputs, to the motor driver, driving control signals for repeatedly adjusting an advance angle and a lag angle at energization switching of the each phase of the motor in a prescribed pattern based on the rotational position information generated by the rotational position detector.

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.

An electronic timepiece enables driving by appropriate drive conditions even when the load on a motor changes. The electronic timepiece includes a motor having a coil; a driver that is controlled to an on state supplying drive current to the coil, and an off state not supplying the drive current; a driver controller configured to control the driver to the on state or the off state based on a control parameter and current value through the coil; and a control parameter setter configured to maintain or change the control parameter based on the on state or the off state control state of the driver controller.

The present invention relates broadly to commutation control of a BLDC motor for use with, for example, a power tool. The method uses a controller to control a BLDC motor in the event of a position sensor failure. Rather than ceasing operation of the motor and indicating a fault or error message to the user, the present invention determines when the next transition should occur based on the time between past hall transitions using a timer. Thus, if one or two position sensors are no longer providing position information to the controller, the controller can determine when the transitions would be changing based on past transitions to continue controlling the motor and prevents the motor from ceasing operation.

The present invention relates broadly to commutation control of a BLDC motor for use with, for example, a power tool. The method uses a controller to control a BLDC motor in the event of a position sensor failure. Rather than ceasing operation of the motor and indicating a fault or error message to the user, the present invention determines when the next transition should occur based on the time between past hall transitions using a timer. Thus, if one or two position sensors are no longer providing position information to the controller, the controller can determine when the transitions would be changing based on past transitions to continue controlling the motor and prevents the motor from ceasing operation.

The present invention relates to a method of commutation control of a BLDC motor. The method uses a controller to control the BLDC motor using a modified six-step commutation. The method adds six intermediate steps that overlap the six-step commutation. Each of the six steps overlap with preceding and following steps, resulting in six additional intermediate steps in which all three phases are active. By doubling the number of steps, current and torque will vary less over time compared with current solutions without increasing the size or changing the design of the motor.

The present invention relates to a method of commutation control of a BLDC motor. The method uses a controller to control the BLDC motor using a modified six-step commutation. The method adds six intermediate steps that overlap the six-step commutation. Each of the six steps overlap with preceding and following steps, resulting in six additional intermediate steps in which all three phases are active. By doubling the number of steps, current and torque will vary less over time compared with current solutions without increasing the size or changing the design of the motor.

Basic current commands of a d-axis and a q-axis are set based on a torque command of a motor. Subsequently, when the rotation speed of the motor is high, an electric angle compensation amount is set to be larger than that when the rotation speed of the motor is low, and a corrected predicted electric angle is set by adding the electric angle compensation amount to a predicted electric angle predicted from an electric angle based on a rotation position of a rotor of the motor from a rotation position detection sensor. Then, current commands of the d-axis and the q-axis are set by multiplying the basic current commands of the d-axis and the q-axis by a correction coefficient based on the corrected predicted electric angle, and an inverter is controlled using the current commands.

An electric working machine according to one aspect of the present disclosure comprises a brushless motor, a rotational position sensor, a detector, and a calculator. The calculator detects, when the brushless motor is inertially rotated, a difference between a detection result obtained by the rotational position sensor and a detection result obtained by the detector and calculates a correction value, based on the difference, for correcting the detection result obtained by the rotational position sensor.