In a controller for an AC rotating electric machine, a failure-state determining circuitry determines a failure state of a magnetic-pole position sensor based on an output signal from the magnetic-pole position sensor. A modulation-ratio switching circuitry outputs a target value of a modulation ratio and also changes the target value to be output based on a result of the failure-state determining circuitry. The modulation-ratio switching circuitry sets, when the magnetic-pole position sensor is determined as being abnormal by the failure-state determining circuitry, the target value to be smaller than in a case in which the magnetic-pole sensor is determined as being normal by the failure-state determining circuitry.

A motor drive device determines whether or not a combination of logic levels of sensor signals S1 to S3 is normal, whenever the logic levels of the sensor signals S1 to S3 are changed. Each of the sensor signals S1 to S3 indicates a rotation position of a rotor. When the combination is not normal, the number of the level changes in each of the sensor signals S1 to S3 is counted. When the count value of any one of the sensor signals reaches a threshold value Cth, supply of power to a motor is stopped.

A method of operating a brushless direct current motor is provided that generates a rotor position dependent pulse width modulation waveform. The waveform can improve motor efficiency and reduce torque variation.

A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element comprising a plurality of vertical Hall elements, each vertical Hall element comprised of a respective group of vertical Hall element contacts selected from among a plurality of vertical Hall element contacts. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage is coupled to receive the signals representative of the plurality of quadrature modulated signals, and operable to perform a sliding window integration using the signals representative of the plurality of quadrature modulated signals and compute an estimated angle of the external magnetic field using the signals representative of the plurality of quadrature modulated signals.

A magnetic field sensor comprises a circular vertical Hall (CVH) sensing element having a plurality of vertical Hall elements. A CVH output stage is included comprising one or more of drive circuits to drive the plurality of vertical Hall elements and produce an analog signal representing a strength of an external magnetic field as detected by the plurality of vertical Hall elements. An analog-to-digital converter is coupled to receive the analog signal and produce a digital signal. A quadrature modulator circuit is coupled to the digital signal and operable to generate a plurality of quadrature modulated signals. A processor stage receives signals representative of the plurality of quadrature modulated signals and computes an estimated angle of the external magnetic field.

A rotating electromechanical machine has a rotor having at least one current-carrying winding and at least one rotor-mounted sensor configured to sense a machine property or parameter during machine operation. Rotor-mounted circuitry dynamically modifies at least one property of the current-carrying winding during machine operation in response to the sensed machine property or parameter.

A method for controlling a three-phase brushless DC motor including a single hall sensor, the method including: A) measuring a deviation angle θ of a mounting position of the single hall sensor and storing; B) starting the motor: outputting six-path PWM signals by the microprocessor to control the operation of the inverter and allowing the single hall sensor to continuously and stably measure a position signal; C) obtaining a rotating angular velocity ω=360°/T in the last 360° electric angle cycle by the microprocessor; D) calculating a real-time position angle α=ωt+θ of a present 360° electric angle cycle by the microprocessor; and E) outputting the six-path PWM signals by the microprocessor to control the operation of the inverter so as to simultaneously energize the three-phase winding (U, V, and W); and switching a current direction of each winding.

A power conversion device includes a printed circuit board, whose mounting surface is opposite to an annular surface formed by an annular stator that constitutes a motor, arranged to be separated from the annular surface with a predetermined distance, and mounted with a Hall element that detects a rotation position of a rotor of the motor on a mounting surface on a side of the stator; an inverter IC that is mounted on the mounting surface on the side of the stator of the printed circuit board to supply a high-frequency current to the stator; and an overheat detection unit that is mounted on the mounting surface on the side of the stator of the printed circuit board and detects an overheated state of the inverter IC. When the overheat detection unit detects an overheated state, the inverter IC restricts or stops a current to be supplied to the stator.

An angle detecting device includes a rotatably supported magnet, and a magnetic sensor disposed opposite to the magnet. An output of the magnetic sensor is changed based on a magnetic flux change due to a rotation of the magnet. The magnet is disposed such that a distance between the magnetic sensor and the magnet is changed by the rotation of the magnet.

A power tool with a combined printed circuit board (PCB) that reduces internal wiring of the power tool and provides a large amount of air flow to internal components. In some instances, the combined PCB has a surfboard shape and includes a motor control unit and power switching elements (Field Effect Transistors or FETs). The combined surfboard PCB is located above the trigger, but below the motor and drive mechanism. In other instances, the combined PCB has a doughnut shape and is located coaxially with a motor shaft. The combined PCB may be positioned between a doughnut-shaped control PCB and the motor.