Abstract: A system includes a permanent magnet generator (PMG) with a generator shaft defining a longitudinal axis. A brake system includes a brake shaft with a first end operatively connected to the generator shaft for selectively rotating with the generator shaft or braking to slow the generator shaft. A shear shaft is operatively connected to a second end of the brake shaft axially opposite the first end along the longitudinal axis. The brake system includes a press fit sleeve engaged about the brake shaft and an actuator. The actuator is operatively connected to actuate a pawl between a first position spaced apart from the press fit sleeve for normal operation of the PMG, and a second position engaged with the press fit sleeve to apply braking forces to the press fit sleeve and to the generator shaft.

Abstract: A work tool includes a motor, a tool-mounting part, a rotary shaft, a rotating member, a switch, an operation member and a lock mechanism. The rotating member is held rotatably around a rotation axis of the rotary shaft and configured to transmit torque to and from the rotary shaft while being allowed to rotate relative to the rotary shaft. The rotating member is configured to rotate together with the rotary shaft by action of transmitting the torque when the operation member is moved from the OFF position to the ON position and the lock mechanism allows the rotating member to rotate, and configured to apply a braking force to the rotary shaft by action of transmitting the torque when the operation member is moved from the ON position to the OFF position and the lock mechanism non-rotatably locks the rotating member.

Abstract: A motorized shade comprising a roller tube, a shade material connected to the roller tube, and a motor drive unit operably connected to the roller tube. The motor drive unit comprises a motor adapted to create torque to rotate the roller tube to lower or raise the shade material and a force sensor positioned at a point along the motor drive unit that resists the torque created by the motor resulting in a reaction force that is detected by the force sensor. The motor drive unit further comprises a motor control module adapted to receive sensor readings from the force sensor and control the motor in response to detecting an abrupt change in the reaction force using the received sensor readings to enable shade control via pulling of the shade material as well as or alternatively obstacle detection to minimize damage to the roller shade and users.

Abstract: The following invention relates to a subsea actuator (16?; 16?) for actuating a subsea rotating component (81; 181); comprising: a first biasing element (82; 182); a motor (85; 185); a holding element (83; 100, 183) configured to receive an input force; a rotatable stem (80?, 80?, 250, 84; 80; 200) operatively connectable to the component; a force transmitting arrangement (84, 80?, 80?; 83, 84; 183?, 195, 201; 84, 99, 86, 101, 83) connectable to the first biasing clement (82; 182) and the holding element (83; 100, 183); a first connection which in a first mode is configured to lock the stem (80?, 80?, 250, 84; 80; 200) in a rotatable engagement with the motor (85; 185) and in a second mode is configured to unlock the stem (80?, 80?, 250, 84; 80; 200) from the rotatable engagement with the motor (85; 185) and allow the stem (80?, 80?, 250, 84; 80; 200) to be influenced by the first biasing element (82; 182); wherein the first biasing element (82; 182) and the stem (80?, 80?, 250, 84; 80; 200) are releasably co

Abstract: A vehicle includes an electric machine, an IGBT, and a gate driver. The IGBT has a gate, an emitter, and a collector and is configured to flow an electric charge through a phase of the electric machine. The gate driver is configured to flow current onto the gate at a first level, and in response to a time integral of a voltage across the phase exceeding a predetermined level, transition from the first level to a second level less than the first level.

Abstract: A storage operating device equipped with a drive that is supplied with electrical energy from a power supply network via an inverter, the inverter having an electrical intermediate circuit, the storage operating device having a control device that is designed to detect a power failure and to react to the same. In order to create a storage operating device and a method for controlling a storage operating device that allows a guided stoppage of the storage operating device in the event of a failure of an electrical power supply network, at a lower cost than is the case in the prior art, the control device has means for detecting a power failure of the power supply network, for the purpose of monitoring the intermediate circuit voltage in the intermediate circuit.

Abstract: A drive system includes a line assembly configured to connect a power converter to an electric motor which has a brake and an encoder. The line assembly has at least two power lines and only two brake lines exclusively to provide a data transfer between the power converter and the electric motor and to transfer energy to the encoder. The power converter applies a first supply voltage of a first polarity and a second supply voltage of a second polarity opposite to the first polarity to the brake lines for supplying the brake and the encoder. The electric motor supplies the encoder with the respective supply voltage independently of its polarity and the brake with the respective supply voltage depending on its polarity.

Abstract: According to a control apparatus for an AC motor, a switching section selects a two-phase control current value as a current fixing value, when a first current detection value of a first phase of the AC motor and a second current detection value of a second phase of the AC motor are normal. The switching section selects an one-phase control current value, which is calculated based on a normal phase current detection value, which is a value of the normal phase and is one of the first and the second current detection values, as the current fixing value, when it is determined that the current supplied to the AC motor has been stabilized after an abnormality is detected in part of the first and second detection values.

Abstract: There is obtained a configuration capable of rapidly decelerating a motor even if a failure occurs in the communication between a controller and a motor control unit in a motor controller in which a speed command is input from the controller to the motor control unit. A motor controller 1 is provided with a main controller 2, and a motor control unit 3 configured to be communicable with the main controller 2 to drive a motor M according to a torque command output from the main controller 2. The motor control unit 3 includes a speed control unit 31 for outputting a torque command, so as to decelerate the motor M, if any failure occurs in communication with the main controller 2 while the motor M is being driven.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: An electric machine assembly with fail-safe arrangement is described. The assembly comprises a stator including a plurality of windings and a cooperating rotor including at least one permanent magnet; a detector configured to detect DC current in at least one of the windings of the stator; and a bypass circuit configured to be activated upon detection of the DC current by the detector and to prevent at least some of the DC current from flowing into the at least one of the windings of the stator.

Abstract: To provide a motor control device which can apply an electric brake to a motor when power supply is stopped, and achieve a miniaturization and a cost reduction. A first switch 11 through a sixth switch 16 connects respective coils L1, L2 and L3 included in a motor to an electric power source 20. The capacitor C accumulates the power supplied from the electric power source 20. A seventh switch 17 connects the capacitor C to a fourth switch 14 through the sixth switch 16, when the power supply from the electric power source 20 is stopped. The operation of the seventh switch 17 causes the fourth switch 14 through the sixth switch 16 to operate by the power accumulated in the capacitor C, and respective coils L1 to L3 are short-circuited to apply the brake to the motor.

Abstract: The method is capable of equalizing time lengths of stopping a motor at load-holding stop positions of respective phases so as to average amounts of heat generation of phase coils. The method for drive-controlling electric machinery, in which a multiphase motor is used as a driving source of an assist mechanism, is performed by a control unit including a driving circuit for driving the multiphase motor. The method is characterized in that the control unit controls to stop a rotor at a load-holding stop position, at which rotation of the rotor is stopped in a state where a motor coil is energized and the rotor is in a load-holding state, and that the load-holding stop position is angularly shifted an electric angle of 180/n (n is number of phases and an integer two or more) degrees, in a prescribed rotational direction, with respect to a previous load-holding stop position of the rotor.

Abstract: A system includes at least one device that includes at least one device component. For a defined movement of the at least one device component, a movement axis and/or a movement direction may be selected by a selection element and may be identified by an activatable lighting element. The identified movement axis and/or the identified movement direction may be released by at least one actuation element, so that a desired movement of the at least one device component may be performed.

Abstract: An electric drive system comprises a generator, a traction motor, a brake resistor, a bus, and a control unit. The generator, the traction motor, and the brake resistor are coupled electrically to the bus. The control unit is configured to determine a pulse-width-modulation duty cycle for the brake resistor (“brake duty”) and control operation of the brake resistor according to the brake duty, wherein the brake duty can be a value intermediate of constant OFF and constant ON. A method of operating the electric drive system is also disclosed.

Abstract: A fan system including a motor with a coil, a storage unit, a driver, and a buffer circuit is provided. The coil module has a first connection terminal and a second connection terminal. The storage unit electrically couples with a voltage source, stores electrical energy when the voltage source is available, and releases the stored electrical energy to carry out a brake operation when the voltage source is unavailable. The driver electrically couples with the first and second connection terminals of the coil module to control a direction of an inductor current passing through the coil module. The buffer circuit electrically couples with the coil module. In the brake operation, the buffer circuit operates to form a transient potential between the first and second connection terminals of the coil module and to consume electrical energy of the inductor current, for gradually stopping the motor in a buffering time period.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: An electrical machine having a stator and a rotor. The stator includes a core and a plurality of windings disposed on the core in a multiple-phase arrangement. The rotor is disposed adjacent to the stator to interact with the stator. A method of operating the motor includes applying a pulsed voltage differential to first and second terminals of the windings resulting in movement of the rotor; monitoring the back electromotive force (BEMF) of the windings to sense rotor movement; after the applying and monitoring steps, monitoring the BEMF of the windings to determine whether the rotor is rotating in a desired direction, and electrically commutating the motor when the rotor is rotating in the desired direction and zero or more other conditions exist.

Abstract: Methods and apparatus to reduce the stopping time of a spindle motor are disclosed. An example method includes detecting a dissipation current flowing in a spinning motor; determining when the dissipation current drops below a threshold value; and, in response to the dissipation current dropping below the threshold value, applying a voltage to the motor to increase the dissipation current for a duration. In some examples, the voltage is removed from the motor when the motor reaches a predetermined rotational velocity to avoid reverse rotation.

Abstract: A powered opening and closing system includes a door supported on a vehicle body, a motor, a drive mechanism for moving the door in opening and closing directions by virtue of power of the motor, an operation detecting sensor for detecting a handle operation when the door is operated to open or close, and a control circuit for prohibiting the operation of the drive mechanism when a predetermined operation prohibiting condition is detected. The drive mechanism brakes the movement of the door by putting the clutch in an engaged state while the motor is kept stopped. While the predetermined operation prohibiting condition is detected, the control circuit controls the clutch to be engaged while keeping the motor stopped when an opening of the door is detected, and controls the clutch to be disengaged when an operation of the handle is detected by the operation detection sensor.

Abstract: In a drive system of an AC motor in which a motor current is feedback-controlled, a motor current command is produced in a normal operation according to a torque command value on an optimum efficiency characteristic line so as to select an optimum current phase maximizing an output torque with a constant motor current amplitude. Conversely, when the AC motor produces an excessively generated power exceeding a regeneratable power quantity of the AC motor, a consuming operation is performed for intentionally increasing the power loss in the AC motor. In the consuming operation, the motor current command is produced according to the torque command value on a loss increase characteristic line to change the current phase from the above optimum value. Thereby, the power loss in the AC motor can be increased to consume the surplus power without causing instability in the motor control.

Abstract: The invention relates to a method for controlled braking of an electrically powered lifting action in the event of a failure, such that at least one of the nominal values for “rotational direction” and/or “operating speed” and/or “door position” and/or “motor capacity” and/or “motor current” is ascertained and compared with an actual value, and such that a motorized braking process or motorized stopping process is triggered by a departure of the actual value from the nominal value that lies outside a predetermined range. In addition the invention relates to a device for applying said method.

Abstract: Disclosed is a motor-driving device capable of protecting an inverter from breakdown. First current-protecting section retains reference voltage value Vref1 as a preset value. If the current to be fed into inverter exceeds value Vref1, first current-protecting section shuts off the output of driver and outputs a first warning to driving-signal generator to shut off generating driving signals. This protects inverter from breakdown. Second current-protection section retains reference voltage value Vref2 that is smaller than value Vref1. If the detected current exceeds value Vref2, second current-protecting section outputs a second warning. Receiving the second warning, driving-signal generator immediately stops generating driving signals; however, it resumes output of driving signals after no longer receiving second warning. The structure above protects inverter from breakdown without frequent stops of brushless motor.

Abstract: A powered opening and closing system includes a door supported on a vehicle body, a motor, a drive mechanism for moving the door in opening and closing directions by virtue of power of the motor, an operation detecting sensor for detecting a handle operation when-the door is operated to open or close, and a control circuit for prohibiting the operation of the drive mechanism when a predetermined operation prohibiting condition is detected. The drive mechanism brakes the movement of the door by putting the clutch in an engaged state while the motor is kept stopped. While the predetermined operation prohibiting condition is detected, the control circuit controls the clutch to be engaged while keeping the motor stopped when an opening of the door is detected, and controls the clutch to be disengaged when an operation of the handle is detected by the operation detection sensor.

Abstract: A device is for braking a magnetic levitation railway, wherein the stator winding of a linear motor is short-circuited as a brake winding in a last section before an end of the route. There is a provision for two stator windings which extend alternately on the stator to be present in a penultimate section.

Abstract: A control unit for a moveable barrier, such as a garage door, includes a microcontroller connected to a motor speed detector, motor current sensor or a sensor for determining forces exerted on or by the barrier. A user interface includes user actuatable switches for setting a first maximum force value to be exerted on or by the barrier when moving in one direction and the microcontroller automatically sets the value of a second maximum force to be exerted on or by the barrier when moving in the opposite direction. The second force value may be based on the force value set by the user or the second force value may be a preset value. Both force limits may be automatically set as a function of a maximum force exerted on said barrier during movement thereof, during a force learning operation.

Abstract: A motor has built therein a brake for stopping the rotation of the motor and a brake controlling circuit for controlling the brake. The motor is further provided with a bypass circuit for supplying an electric power directly to the brake and a terminal for connecting a power source to the bypass circuit. When the brake controlling circuit develops a fault, the brake is directly released by an external power source.

Abstract: A motor power supply including a DC supply part having a pair of supply terminals; an inverter having a pair of connection terminals respectively connected to the supply terminals thereof to receive DC power therefrom and to supply AC power to a motor, a breaking resistor and a control switching element disposed in parallel in an additional line connecting the pair of connection terminals to each other, a control switching element disposed with the breaking resistor in the additional line, a breaking switch disposed to one of the connection terminals and switched to either a normal position or a breaking position connecting the one connection terminal to a corresponding supply part or to the additional line, a speed detector detecting a motor speed and a control part controlling the breaking switch to switch to the breaking position and controlling the control switching element so that an on-off interval of the control switching element is controllable depending on the detected speed.

Abstract: A vehicle driving force control apparatus is configured to prevent co-rotation of the motor caused by rotation of a pair of wheels when a clutch connecting the wheels and the motor is released (disconnected). When the clutch is released, the motor is braked by short circuiting the armature. The motor is then braked again by setting the field current of the motor to 0 when the rotational speed of the motor reaches 0. After the clutch is released, a braking-direction field current is applied to the motor in accordance with the decreasing rotational speed of the motor such that the braking force is decreased as the rotational speed of the motor decreases.

Abstract: A method for the orientation of a spindle of a numerically controlled and rapidly rotating spindle by which the spindle is brought from an initial rotational speed into a predetermined position of rest. The method includes performing a first phase of orientation of the spindle by braking the spindle to a threshold rotational speed, wherein during the braking a switching over to a position controller is prepared, the switching over is performed at a switching time during a transition from the first phase of orientation to a second phase of orientation, the switching over is continuous in regard to position and/or rotational speed, and wherein a rotational speed of the spindle drops strictly monotonically.

Abstract: The position-controlled stopping of rotating components of shaftless drive mechanisms, in the case of a loss of voltage, is accomplished by the provision of an external connectable network. That external connectable network supplies the process power which is missing due to a loss of rotational power in the event of a voltage loss.

Abstract: A retarded electric motor designed as a series motor or an asynchronous motor having a squirrel cage rotor. A valve is provided for switching between motor operation and braking operation. During motor operation the motor is operated in a known configuration as series motor or as asynchronous motor. If configured as a series motor, the valve (S1, S2, S3) allows to bypass the armature and to operate the motor as an externally excited direct current generator when switching into braking operation. If configured as an asynchronous motor, a switch is utilized to disconnect at least two field windings from mains. A valve is utilized to excite the motor externally from mains with a pulsating direct current during braking.

Abstract: A circuit for controlling a motor's operation is disclosed. The circuit includes a relay and a motor braking circuit portion. The relay selectively interconnects a voltage source with one of a braking terminal and a motor terminal. The motor braking circuit portion has a motor brake switch connected on a first switch side to the motor terminal and a second switch side to the electrical ground. The brake switch is activated to brake the motor when the relay interconnects the voltage source with the braking terminal.

Abstract: A small permanent magnet is affixed to the protruding portion of a rotor of a motor that is coupled to gears in a gear enclosure. The rod of a window covering is coupled to the gears such that when the motor is energized by a user command signal, the window covering moves. At least one pick-up coil is affixed to the receptacle of the gear enclosure, such that when the motor with magnet turns, the pick-up coil senses magnetic pulses that can be used to determine the speed, position, and direction of rotation of the motor.

Abstract: A movable barrier operator (10) can have at least two automatic modes of operation. These modes of operation can differ from one another at least with respect to their respective utilized maximum-applied-force thresholds, such that one of the modes of operation correlates to a reduced maximum-applied-force threshold. Selection between these available maximum-applied-force thresholds can be based, at least in part, upon whether an obstacle detector is operably coupled to the movable barrier operator. In one embodiment, a primary controller (30) and a secondary controller (31) can be utilized to effect the controlled selection and usage of the available maximum-applied-force thresholds. In another embodiment, maximum permitted speed of travel for the movable barrier can also be determined, at least in part, as a function of whether an obstacle detector is available to the movable barrier operator.

Abstract: A motor control apparatus and a motor control method that instruct deenergization of a motor a predetermined period of time after an arrival of a subject to be driven by the motor at a speed measuring position. The predetermined period of time corresponds to a current speed of the motor upon arrival of the subject to be driven at the speed measuring position, and the speed measuring position is at a predetermined distance before a target stop position of the subject to be driven.

Abstract: A control system for controlling the operation of an electric motor driven door or gate operator unit having a speed reducing gear drive mechanism and a brake unit for positive braking of the motor output shaft. A programmable microcontroller is operably connected to a motor drive circuit with interlock relays to energize the drive motor for rotation in opposite directions. The motor drive circuit is interconnected with a motor watchdog circuit to effect motor shutdown if the microcontroller malfunctions and a brake release circuit to prevent motor operation unless the brake is energized. The microcontroller is operable to store door mid-stop time delay values, braking rates, a door position limit overrun signal, a door cycle count, door reversals upon receiving an obstruction detector signal and error codes associated with door operator and control system malfunctions. The brake may be controlled on a variable duty cycle to provide smooth braking action in both directions of movement of the door.

Abstract: A liquid dispensing system increases the precision, reliability, and safety of dispensing medications and other liquids. An electronic brake grounds a power terminal of a pump motor to absorb the kinetic energy of the motor and other mechanically coupled components. The electronic brake reduces overage and overage variation in the dispensing of liquids at very little cost or complexity. A watchdog circuit monitors a controller heartbeat signal and disables the motor in the absence of a regular beat. The watchdog circuit along with redundant power switches greatly reduce the possibility of motor runaway in the event of component failure. A controller begins or ends each dispensing cycle with a diagnostic which determines whether the liquid dispensing system is fully operational. If not, the controller may disable the motor, emit an alarm tone, and display an alarm message.

Abstract: A region judging circuit judges an electric angle region of a three-phase brushless DC motor based on an output signal of a resolver. A latch timing output circuit determines an optimum latch timing. A driving direction judging circuit judges a rotational direction of the motor based on a comparison in largeness between a pair of phase currents. A latch circuit latches a judgement result of the driving direction judging circuit at the latch timing designated by the latch timing output circuit and retains the judgement result until the next latch timing comes.

Abstract: A motor control apparatus and a motor control method according to a first aspect of the invention are configured to instruct deenergization of a motor a predetermined period of time later than arrival of a subject to be driven by the motor at a speed measuring position. The predetermined period of time corresponds to a current speed of the motor upon arrival of the subject to be driven at the speed measuring position, and the speed measuring position is at a predetermined distance before a target stop position of the subject to be driven.

Abstract: A mains braking device for a line-powered power tool includes a circuit arrangement with a two-pole switch which switches between the motor mode and the braking mode. The inventive braking device further includes an electronic power circuit breaker or triac which is connected in series to the commutator motor of the power tool and with control electronics allocated to the triac. For the safe recognition and initiation of the mains braking mode, the control electronics is provided with devices for differentiating between the motor mode and the mains braking mode. The mains braking device is especially useful for power tools such as right angle grinders, hand-held buzz saws and the like which are provided with dangerous tools.

Abstract: The present invention provides a motor drive controller for a vehicle having an engine and a motor disposed therein as a vehicle-propulsion system, the motor having both driving and power-generating functions, comprising: an engine controller for controlling a running state of the engine; motor controller for controlling both driving and power-generating states of the motor in a manner independent of control over the engine gained by the engine controller; engine speed-detector for detecting an engine revolution of the engine; and, engine load-detector for detecting an engine load. The motor controller includes a map defined by respective detection signals from the engine speed detector and the engine load-detector. The motor controller functions to provide alternative control between driving and power generation of the motor in response to a torque instruction value that is retrieved from the map.

Abstract: Electric motors, in particular geared motors, are often equipped with electromagnetically actuated mechanical brakes. In order to ensure that an excitation coil (3) can be operated with alternating-current mains supplies of various voltages, it is proposed to generate a unipolar voltage that varies over time with a certain period by means of a voltage source (2), the output voltage of which is positive and different from zero in a first time segment of this voltage period and in this first time segment has a maximal value, and in a second segment of the voltage period is zero or approaches zero. To pass an excitation current from the voltage source (2) to the excitation coil (3), a current path (15) is provided that is opened substantially at the beginning of the first time segment. The current path (15) is blocked again at a certain point within the first time segment, this point being selected such that the excitation current does not exceed a predetermined maximal value.

Abstract: A motor driver has a braking control circuit. The braking control circuit shuts off the supply of an electric current to the coils included in the motor when a motor control signal shifts to a predetermined level and, after a predetermined length of time secured in accordance with an index signal, starts application of braking to the rotation of the motor by the use of a braking circuit. The index signal is obtained from the signal that indicates the rotational position of the motor. The motor control signal is fed from a control signal generating circuit to the braking control circuit.

Abstract: A number of embodiments of electric motor controls for electric power assisted vehicles. The controls all provide for regenerative braking to be automatically enabled upon the sensing of a failure in the control system. The regenerative braking is, however, discontinued once the vehicle stops so that it can be easily pushed by hand without drag from the electric motor.

Abstract: The arrangement or apparatus for operating a magnetically suspended, electromotoric drive apparatus in the event of a mains disturbance comprises a drive converter feeding the drive apparatus, a driver feeding a magnetic bearing and a voltage converter, which are connected to a common intermediate circuit. The voltage converter feeds a stopping control apparatus and the drive converter can be switched to a regeneratively acting mode of operation by the stopping control apparatus in the event of a mains disturbance in order to provide at least the driver feeding the magnetic bearing and the stopping control apparatus with electrical energy via the intermediate circuit.

Abstract: A spindle motor control method stops a spindle motor which rotates in a forward direction in response to a rotation signal. The spindle motor control method includes two steps. First, a brake signal is supplied to the spindle motor for rotating the spindle motor in a reverse direction when stopping the spindle motor which rotates in the forward direction. Second, the rotation signal and the brake signal are put in an OFF state when a frequency generator signal FG, which indicates a rotational phase of the spindle motor and is generated based on an output of the spindle motor, is not detected for a predetermined time.

Abstract: Apparatus for braking either a linear or rotary electric motor having no permanent magnets comprising at least one position sensor for outputting an electrical characteristic representative of motor position and an electronic circuit for generating a pulsed control signal for controlling the braking of the motor. The electronic circuit of the present invention may be responsive to any emergency such as loss of line power, a motion controller failure, or actuation of a limit switch by a driven member.

Abstract: A method of smoothly stopping pump drives without pressure surges is provided. To accomplish this, the phase control angle between the motor current and the motor voltage is increased according to a linear ramp starting from 0.degree. with the help of an a.c. power controller, where the phase angle decreases and reaches a turning point. If the turning point is detected by observing the phase angle, the phase control is based on this by means of a controller with a predefined linear phase angle reference curve as a function of time. Then the motor rpm does not change abruptly because a rapid change in phase angle is prevented.

Abstract: A brushless motor includes a stationary member; a rotating member rotatably supported with respect to the stationary member; a stator provided in the stationary member and provided with a stator coil for generating current magnetic field under an exciting state; and a rotor magnet provided in the rotating member for obtaining a revolutionary power due to an electromagnetic mutual effect with the current magnet field of the stator coil. The rotor magnet is formed such that segment-shaped magnets are placed annularly with predetermined gaps circumferentially. The gaps are filled with a magnetic resin material.