Abstract: A slope counter starts countdown at timing of changing an output voltage of an FET to zero. A controller executes a nonsymmetrical energization control operation to control a PWM generator such that the PWM generator generates a PWM signal based on a count value of the slope counter and outputs the generated PWM signal to the FET. The countdown of the slope counter is terminated when a predetermined time period elapses or when a time period corresponding to an electrical angle of 40 degrees elapses before the elapsing of the predetermined period. Also, at this time, the controller terminates the nonsymmetrical energization control operation.

Abstract: An angle detecting apparatus includes a rotor fixed to a rotating shaft, a pair of magnetic sensors arranged close to the outer periphery of the rotor so as to have a difference in angle (?/2) with respect to the center of rotation of the rotor, a differential operational circuit performing differential operation on detection signals output by the magnetic sensors to output a differential signal, and the angle calculating circuit calculating the angle of rotation of the rotating shaft based on the differential signal. The planar shape of the rotor is such that the sum of the distances between the center of rotation and the respective two points where two straight lines crossing at the center of rotation at a crossing angle of (?/2) cross the outer periphery of the rotor is constant, and the planar shape is symmetric with respect to a straight line passing through the center of rotation.

Abstract: A motor driving circuit includes an inverter circuit which supplies a driving current to a coil of a single phase brushless DC motor, a position detection sensor which detects a magnetic pole position of a magnet rotor of the motor and outputs a position detection signal, and a controller which controls the inverter circuit based on the position detection signal and a speed instruction signal for instructing a rotating speed of the motor. At a time of startup of the motor, the controller makes a pulse width of a PWM signal for controlling the inverter circuit constant in a first time period which starts after the position detection signal zero-crosses and lasts until the position detection signal zero-crosses next time, and narrows the pulse width of the PWM signal as time elapses in a second time period immediately after the first time period.

Abstract: A method of aligning a sensorless brushless polyphase DC motor including aligning a rotor to a known stopped position with respect to at least one coil during a shut-down of said motor wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps; and, starting said rotor from said known stopped position, wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps.

Abstract: A system for determining a commutation state for a brushless DC motor includes a controller configured to control current that is applied to drive each of a plurality of phases of the motor. A time delay system is configured to measure, for a given commutation state, a time delay from when a voltage associated with a driven phase of the plurality of phases crosses a predetermined threshold and a voltage associated with a floating phase of the plurality of motor phases crosses the predetermined threshold. Logic is configured to determine the commutation state for the motor based on the measured time delay.

Abstract: A motor control device is configured in such a manner that a current detection circuit and an exciting circuit for a motor resolver share one grounding wire. A microcomputer that serves as a current detector sets a phase of an exciting current in such a manner that values of an excitation noise superimposed on an output voltage of the current detection circuit at respective timings (L1, H1, L2, H2, . . . ), at which the output voltage is acquired in one current detection process, are equal to each other. An electric power steering system is provided with the motor control device.

Abstract: Systems and methods of controlling a permanent magnet motor without a mechanical position sensor are provided. In accordance with one embodiment, a motor control system includes an inverter configured to receive direct current (DC) power and output a power waveform to a permanent magnet motor, driver circuitry configured to receive control signals and drive the inverter based upon the control signals, a current sensor configured to determine a sampled current value associated with the power waveform, and control circuitry configured to generate the control signals based at least in part upon a comparison of a flux-producing component of the sampled current value and a flux-producing component of a command reference current value.

Abstract: The present invention discloses a controller and a method for adaptively adjusting motor driving current waveforms. According to the present invention, the controller receives multiple different control parameters which may be determined according to the characteristics of a fan to be controlled, and adjusts the delayed ON time and advanced OFF time of a PWM driving signal based on the control parameters and the present rotation speed of the fan motor, so that the fan operates under an optimum driving current waveform.

Abstract: A control apparatus is to drive a power converter. The power converter has a power supply unit, a switching member electrically connected to the power supply unit, and a power accumulator electrically connected to the switching member. The control apparatus controls a rotary machine with a terminal electrically connected to the power accumulator. A calculator calculates, based on a command voltage to the rotary machine, a command value for an output current to the power accumulator and the rotary machine. A chopper control unit carries out chopper control of the power converter by switching on and off the switching member based on the command value for the output current to thereby convert a voltage across the power accumulator into a desired voltage relation to a voltage of the power supply unit.

Abstract: A filter representing a complex impedance of a motor system based on a deviation between a first voltage driven by a command signal and a second voltage driven by the command signal can be dynamically adjusted. The motor system can be held in a steady state, eliminating back electromotive force, by providing zero mean current excitation.

Abstract: A supply current control circuit controls the voltage of a low-voltage direct-current power source so that the average current of an inverter circuit detected by a current detecting circuit becomes constant at a specified current value. Accordingly, characteristics that are little in the amount of change of air volume are obtained.

Abstract: A sensorless motor drive device has: a first operation mode of generating current waveforms including non-energizing times based on a first rotor position signal generated by detecting zero crossings in windings of a motor as a signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms; and a second operation mode of generating current waveforms including no non-energizing time based on a second rotor position signal generated without use of zero crossings as the signal indicating the rotor position of the motor, and supplying currents to the windings of the motor according to the current waveforms. The first and second operation modes can be switched to each other.

Abstract: A method wherein the signals (SW1, Sw2, Sw3) controlling the power supply (10) of the phase windings (4) of the motor consist of signals (So1, So2, So3) that are out-of-phase by a phase angle (f) which is continuously variable in relation to synchronization signals (Si1, Si2, Si3) generated by sensors (1) detecting the position of the rotor. According to the method, a processing unit (5) comprises inlets (8) for receiving the synchronization signals and outlets (6, 7) for transmitting the out-of-phase signals. The synchronization signals are binary signals presenting synchronization fronts and the rising and falling fronts of the out-of-phase signals are generated, following a level switching time depending at least on the phase angle, from at least one reference front selected from the synchronization fronts such that the switching time is minimum.

Abstract: A device for detecting the angular position of a rotor of a polyphase rotary electrical machine contains a stator and a plurality of magnetic field sensors (200) delivering first signals (2001-2003) representing a magnetic field. The device includes means (201) for generating, from linear combinations of the first signals, first (2010) and second (2011) sinusoidal signals, phase-shifted by a determined value ? representing an angular position of the rotor, referred to as real. The device includes means for detecting a value for an angular position of the rotor referred to as estimated (221) by locking between the real and the estimated angular positions using a feedback loop known as a “tracking” loop (214-216, 215-207). The device may relate to a polyphase rotary electrical machine containing such a device.

Abstract: An interface cord is operable to connect an external controller to an electrical machine. The interface cord includes a first connector having a first pin configuration, a cable coupled to the first connector, a second connector coupled to the cable and having a second pin configuration different from the first pin configuration, and a circuit board with a programmable electrically coupled in circuit between the first connector and the second connector.

Abstract: Brushless DC motor (4) is driven based on a first or second waveform signal output from operation switching unit (11), which switches output so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thus, there is provided a motor driving device in which drive is stable even at high speed/under high load, and a driving range is extended.

Abstract: Brushless DC motor (4) is driven based on a first or second waveform signal output from switching determination unit (11), which switches outputting so that a first waveform signal by first waveform generation unit (6) is output when the speed of rotor (4a) is determined to be lower than a predetermined speed, and a second waveform signal by second waveform generation unit (10) is output when the speed of rotor (4a) is determined to be higher than the predetermined speed. Thereby, drive is stable even at high speed/under high load, and a driving range is extended.

Abstract: A method of controlling a brushless motor that includes rectifying an alternating voltage to provide a rectified voltage having a ripple of at least 50%, exciting a winding of the motor with the rectified voltage, and performing a first process or a second process in response to current in the winding exceeding a threshold that is proportional to the rectified voltage. The first process includes freewheeling the winding, while the second process includes continuing to excite the winding for an overrun period and freewheeling the winding at the end of the overrun period. Additionally, a control system that implements the method, and a motor system that incorporates the control system.

Abstract: The invention specifies a circuit arrangement (1, 20) for controlling a brushless electric motor (37) with a control chip (2), particularly a microcontroller, which has a number of PWM contacts (8), which can be used to output a PWM signal, and a number of commutation contacts (5,5?, 6,6?, 7,7?), which can be used to output a commutation signal. In this case, provision is made for at least one commutation contact (5,5?, 6,6?, 7,7?) to be alternately controllable as an input and an output, for the at least one commutation contact (5,5?, 6,6?, 7,7?) to have its output electrically connected to a PWM contact (8), and for the commutation contact (5,5?, 6,6?, 7,7?) connected in this manner to be able to be contacted for the purpose of tapping off a control signal. Such a circuit arrangement (1,20) increases the control options for a given control chip (2). The number of PWM sources required is reduced.

Abstract: A method and system is provided for starting a motor which is useful, among other things, is useful for motors under unknown or variable load/inertia conditions. If a first attempt to start the motor using a first frequency ramp-up rate fails, a subsequent start attempt may be performed at a decreased frequency ramp-up rate. Iteration may be performed until starting of the motor is successfully achieved.

Abstract: A method and apparatus are provided for operation of a three-phase rotating electrical machine which has at least two stator winding sets and each stator winding set has three phase windings connected in star, and the star circuits of the stator winding sets have a phase shift of 30 degrees electrical with respect to one another, and an associated converting unit is respectively provided for each stator winding set, in which method the respective stator winding set is fed by the associated converter unit, and a respectively associated regulation device is provided for each converter unit, and each converter unit is driven by means of a drive signal from the associated regulation device independently of regulation devices of the respective other converter units.

Abstract: The control apparatus for a power conversion apparatus having chopper circuits and a capacitor, each of which includes a switching circuit and a coil, the switching circuit being on/off-controlled in accordance with specific timings determined in accordance with a current flowing through the coil to create required voltage in the capacitor, includes a function of evenly dividing an interval between adjacent specific timings of one of the chopper circuits to produce divided timings to be allocated to the other chopper circuits, and a function of setting, for each of the other chopper circuits, an on-time period of the switching circuit such that, when the interval varies as a result of which the specific timing of each of the other chopper circuits deviates from a corresponding one of the divided timings, an interval between adjacent specific timings of each of the other chopper circuits is varied to reduce the deviation.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an electric (e.g., IPM) machine. The systems and methods implement a field weakening and a torque linearity control loop for linearizing torque generated by an electric machine. As a result, torque linearity is maintained when the electric machine operates in the field weakening region.

Abstract: Disk drive spindle jitter is comprised of electrical noise, error due to pair pole asymmetry, and random disk speed variances. Error caused by pair pole asymmetry can be identified and compensated for by detecting over a single rotation of a rotor a plurality of zero cross signals. These signals can be statistically analyzed over a period of a plurality of revolutions of the rotor so as to identify the systematic error caused by pair poles. Once identified, this pair pole error can be used to modify zero cross signals and/or modify commutation signal driving the disk so as to arrive at a more accurate determination of disk speed and to precisely control the speed of the disk.

Abstract: A brake-controllable brushless motor has a rotor and a stator having polyphase coils; a polar position detector whereby electric power is supplied to the coil selected by its phase in response to the polar positions of the rotor detected by the polar position detector; a driver division for controlling the electric supply to the coils; a motor pulse identifier for recognizing motor pulse signals fed from the polar position detector; and a delayed pulse generator for producing phase-delayed pulse signals in response to the pulse signals fed from the motor pulse identifier, thereby ensuring that when the brushless motor is braked, the phase delay of the delayed pulse signals is progressively and continuously enlarged, and that the coils receive a controlled electric supply from the driver division in response to the delayed pulse signals.

Abstract: A focus controller configured to control focus of an optical element includes a focus state detector configured to detect a focus state based on a contrast value of an image formed by the optical element, and a driving mechanism that moves the optical element including a motor, a position sensor configured to detect a position of a rotor in the motor, and a driving controller configured to select, in accordance with the contrast value, first driving configured to switch an electrization to a coil in accordance with an output of the position senor, or second driving configured to switch the electrization to the coil in the motor in accordance with a determined time interval.

Abstract: A system for controlling a trapezoidally (square wave) driven DC motor includes a unipolar commutation circuit coupled between a DC power supply and a brushless DC motor. The motor has three phases formed by respective stator windings coupled at respective proximal ends to a common node and having respective opposite ends remote from the common node. The commutation circuit drives the motor according to a commutation cycle including three primary steps. During each primary step, one of the phases is driven while the other two phases are not driven. Voltages at the remote ends of the undriven phases are sensed, and timing signals are generated at points where the voltages coincide. The timing signals are used to determine motor position and speed, and to synchronize the commutation cycle with motor position and speed. In one embodiment, the commutation cycle includes transitional steps between the primary steps for smoother operation.

Abstract: A method and apparatus for electronic commutation of a pulse width modulation (PWM) controlled motor involves temporarily increasing the frequency of one or more PWM drive signals applied to the motor upon the occurrence of an asynchronous commutation event.

Abstract: Systems and methods are disclosed to provide torque linearity in the field-weakening region for an IPM machine. The systems and methods adjust the q-axis and the d-axis components of the stator current commands of the IPM machine using a flux weakening and a torque linearity control loop respectively. Thereby, torque linearity is maintained during the field weakening region of operation of the IPM machine.

Abstract: To further improve the stability of drive control for the start period of a motor without complicating a circuit configuration. During the period in which the rotational speed of a rotor does not reach the rotational speed capable of locking a PLL circuit, a drive control method of two-phase mode in which a start current is supplied by two energizing patterns is used. In energizing pattern A, a current is caused to flow in a motor winding in the direction from U to W and in the direction from V to W at the same time. In energizing pattern B, a current is caused to flow in the motor winding in the direction from W to U and in the direction from W to V at the same time. A potential difference Vu-v between a U phase and a V phase in which the phase and magnitude of voltage drop due to inductance are equal is detected. Based on the detected potential difference Vu-v, a magnetic flux estimation signal ?u-v is calculated by an integrator.

Abstract: A fan system includes a driving device, a speed detecting device and a logic device. The driving device generates a speed detecting signal and a predetermined alarm signal. The speed detecting device, which is electrically connected with the driving device, receives the speed detecting signal, and generates a low speed signal when the speed detecting signal is lower than a reference signal. The logic device is respectively electrically connected with the driving device and the speed detecting device, and generates an alarm signal when the logic device receives the predetermined alarm signal or the low speed signal.

Abstract: A control system includes a controller configured to provide a drive signal, and a switching device configured to generate an output control signal as a function of the drive signal in an on-state mode of operation. The control system also includes a timing network configured to receive the drive signal and output a gated signal to the switching device, wherein the gated signal maintains a relationship with a predetermined threshold during the on-state of operation of the switching device.

Abstract: A method of aligning a sensorless brushless polyphase DC motor including aligning a rotor to a known stopped position with respect to at least one coil during a shut-down of said motor wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps; and, starting said rotor from said known stopped position, wherein a voltage is applied to one or more coils in a timed sequence of voltage application steps.

Abstract: The invention relates to an electronically commutated motor (10) and to a method of controlling an electronically commutated motor (10). In order to reduce commutation noise, it is proposed to influence the working range of the power-stage transistors (20, 22) with the aid of a component (48), in such a way that each transistors produces, during energization of each respective stator winding, a substantially constant current through the stator winding (12, 14). Preferably, each power-stage transistor operates within a pinch-off range.

Abstract: A motor drive unit includes a controller configured to drive a motor to a target position by using a first driving mode in which a state of energization of coils of the motor is switched in accordance with outputs from rotor position detectors and a second driving mode in which a state of energization of the coils is switched on the basis of a predetermined time interval. The controller turns on the energization of the coils during a predetermined time under an energization condition at a completion of driving to the target position when the rotor position detectors detect that the rotor position shifts from the target position after turning off the energization of the coils according to the completion of driving to the target position.

Abstract: A method for detecting initial magnetic pole position in permanent-magnet motor first determines a PWM pulse width Dt applied to stator, where the PWM pulse width Dt depends on motor parameters. Six voltage vectors are then successively applied to the stators and the associated current rising time are calculated. The position of rotor is determined based on the shortest current rising time. The voltage vectors are again successively applied to the stators to recalculate the position of rotor. The position of rotor can be precisely determined when the two calculations are consistent. When the two calculations are not consistent, the voltage vectors are again successively applied to the stators to recalculate the position of rotor until the calculations are consistent. The set current level can be larger than the motor rated current, for example, 160% motor rated current, to facilitate the determination of current rising time.

Abstract: A semiconductor integrated circuit capable of reducing the influence of the difference in ambient temperature etc. and realizing a stable phase adjustment circuit has been disclosed. The semiconductor integrated circuit comprises a delay time adjustment circuit for delaying the rising edge or the falling edge of an input signal and changing the amount of delay, a comparison circuit for comparing an output signal from the delay time adjustment circuit with a predetermined voltage, a high-level shift circuit for shifting an output signal from the comparison circuit into a signal on the basis of an output reference voltage, and an output amplifier circuit for amplifying an output signal from the high-level shift circuit and outputting a signal for driving the semiconductor device, wherein the delay time adjustment circuit, the comparison circuit, the high-level shift circuit, and the output amplifier circuit are formed on a single chip.

Abstract: A method and apparatus for electronic commutation of a pulse width modulation (PWM) controlled motor involves temporarily increasing the frequency of one or more PWM drive signals applied to the motor upon the occurrence of an asynchronous commutation event.

Abstract: When starting a brushless motor, if the stop position of the rotor is detected between time t1 and time t2, a start-up excitation pattern in accordance with the rotor stop position is input for an initial energization time Ts1. Afterward, when the energization is stopped, a plurality of signals SL1, SL2, SL3, SL4 are generated in sequence in excitation switch timing signals in accordance with the rotational position of the coasting rotor. From these signals SL1 to SL4, the rotor position is detected using the second and subsequent signals SL2 to SL4 and then the process shifts to ordinary energization switch control. In accordance with the present invention, it is possible to start up a motor in a short time with a simple method so as to obtain a large torque during start-up.