The present disclosure relates to a brushless DC electric motor, such as for an actuator unit of an implant, as for a cardiac assist system, with a stator with a hollow-cylindrical iron-free winding and a rotor which can rotate relative to the stator. A shaft has a number p of pairs of permanent-magnetic poles, and the winding has a number n of three-phase systems separate from one another. The number of n three-phase systems separate from one another, is varied based on a number p of pairs of permanent-magnetic poles, and the systems are arranged in a manner spatially offset from one another by an angle of 360°/n.

A motor commutation waveform generating circuit is provided. The motor commutation waveform generating circuit includes: an edge detection circuit, configured to receive sensing signals of the motor and derive a clock signal indicating a commutation switching point of the motor; an angle cutting circuit, controlled by the clock signal to generate an angle indication pulse indicating a rotation angle of the motor; a synthetic wave generating circuit, using the angle indication pulse to sequentially change waveform voltages corresponding to required angles and output them in segments; and a signal combining circuit, controlled by the clock signal to combine waveform voltage signals generated by the synthetic wave generating circuit, thereby obtaining a plurality of synthetic waveforms provided to a drive control system of the motor for drive control after pulse width modulation.

A motor commutation waveform generating circuit is provided. The motor commutation waveform generating circuit includes: an edge detection circuit, configured to receive sensing signals of the motor and derive a clock signal indicating a commutation switching point of the motor; an angle cutting circuit, controlled by the clock signal to generate an angle indication pulse indicating a rotation angle of the motor; a synthetic wave generating circuit, using the angle indication pulse to sequentially change waveform voltages corresponding to required angles and output them in segments; and a signal combining circuit, controlled by the clock signal to combine waveform voltage signals generated by the synthetic wave generating circuit, thereby obtaining a plurality of synthetic waveforms provided to a drive control system of the motor for drive control after pulse width modulation.

An estimation device that estimates a state of a device that detects a position of a rotating body includes a position sensor to output a detection signal that is a signal representing a detection result of a position of a magnet rotatable in conjunction with the rotating body according to a magnetic flux of the magnet, an extractor to extract a feature amount of the detection signal from the detection signal for each of the positions, and an estimator to derive an evaluation value representing a comparison result between a feature amount of the detection signal for each of the positions and a reference value for each of the positions, and to estimate a degree of change in sensitivity to detect the position based on the evaluation value.

An estimation device that estimates a state of a device that detects a position of a rotating body includes a position sensor to output a detection signal that is a signal representing a detection result of a position of a magnet rotatable in conjunction with the rotating body according to a magnetic flux of the magnet, an extractor to extract a feature amount of the detection signal from the detection signal for each of the positions, and an estimator to derive an evaluation value representing a comparison result between a feature amount of the detection signal for each of the positions and a reference value for each of the positions, and to estimate a degree of change in sensitivity to detect the position based on the evaluation value.

A drain cleaning machine includes a brushless direct current (DC) motor configured to rotate a snake about the snake axis. An electronic processor is configured to control power switching elements to drive the brushless DC motor. In a first operating range when a load experienced by the brushless DC motor is less than or equal to a predetermined load, the electronic processor is configured to control the power switching elements to drive the brushless DC motor at an approximately constant speed regardless of the load experienced by the brushless DC motor. In a second operating range when the load experienced by the brushless DC motor is greater than the predetermined load, the electronic processor is configured to control the power switching elements to drive the brushless DC motor at a decreasing speed as the load experienced by the brushless DC motor increases.

A drain cleaning machine includes a brushless direct current (DC) motor configured to rotate a snake about the snake axis. An electronic processor is configured to control power switching elements to drive the brushless DC motor. In a first operating range when a load experienced by the brushless DC motor is less than or equal to a predetermined load, the electronic processor is configured to control the power switching elements to drive the brushless DC motor at an approximately constant speed regardless of the load experienced by the brushless DC motor. In a second operating range when the load experienced by the brushless DC motor is greater than the predetermined load, the electronic processor is configured to control the power switching elements to drive the brushless DC motor at a decreasing speed as the load experienced by the brushless DC motor increases.

Apparatuses, systems, and methods for sensing rotary positions are provided. For example, an example rotary position sensor includes a rotor assembly having a rotor assembly opening for securing the rotor assembly to a shaft structure, a stator assembly having a stator assembly opening for receiving the shaft structure, and a base assembly secured to the stator assembly. In some examples, the base assembly (such as, but not limited to, a PCB assembly) comprises a plurality of primary coil elements printed on a first side of the base assembly and a plurality of secondary coil elements printed on a second side of the base assembly.

Apparatuses, systems, and methods for sensing rotary positions are provided. For example, an example rotary position sensor includes a rotor assembly having a rotor assembly opening for securing the rotor assembly to a shaft structure, a stator assembly having a stator assembly opening for receiving the shaft structure, and a base assembly secured to the stator assembly. In some examples, the base assembly (such as, but not limited to, a PCB assembly) comprises a plurality of primary coil elements printed on a first side of the base assembly and a plurality of secondary coil elements printed on a second side of the base assembly.

An actuator control device that controls an actuator according to an angle of a rotating portion includes a processor configured to: calculate a target relative angle from a rotation start angle to a target angle; detect a sensor detection angle from a sensor; calculate an angular velocity of the rotating portion based on a change amount of the sensor detection angle in a predetermined calculation cycle; correct the angular velocity to be closer to a normal angular velocity when the angular velocity is greater than or equal to a first threshold or less than or equal to a second threshold; calculate an actual relative angle by integrating the angular velocity and a corrected angular velocity; and feedback-control the actuator according to a deviation between a target relative angle and the actual relative angle.