Abstract: A frequency converter device (the present invention) is disclosed for controlling the speed of a single-phase asynchronous motor wherein the controlled rotational speed keeps the slip between the speed of a driving rotating magnetic field and a speed of a rotating motor rotor smaller than prior art. Two voltages (Vaux and Vmain) with independent amplitudes, an approximate 90° phase shift relative to each other, and a common frequency are provided by the frequency converter device from a single AC or DC supply voltage. By independently adjusting the amplitudes of said voltages Vaux and Vmain on the motor windings, a greater current can flow at lower frequencies than is possible with the prior art with the rising reactance (at lower frequencies) of its capacitor, and the higher current results in greater torque. The ability to lower the RPMs with more torque to the motor rotor results in less slip than the prior art and thus increases efficiency.

Abstract: A motor controlling device configured to control an on-board motor is provided, which includes an H-bridge type drive circuit comprised of first switching elements and configured to drive the on-board motor, and a controlling circuit configured to control the on-board motor by controlling the drive circuit, the controlling circuit carrying out an ON control of one of the first switching elements connected to ground, when not operating the on-board motor.

Abstract: An embodiment relates to a motor including a shaft, a rotor coupled to the shaft, a stator disposed outside the rotor, a sensing magnet disposed on the shaft, and a coupling member disposed to cover the sensing magnet, wherein the coupling member is inserted into a first groove concavely formed in an end portion of the shaft. Accordingly, combinability and assemblability of the sensing magnet and the shaft can be secured using the coupling member formed to have an elastic structure in the motor.

Abstract: A rotary encoder that is capable of securing a sufficient synthesis tolerance while achieving miniaturization is provided. The rotary encoder 1 includes a rotor 3, a stator 4, and a calculating unit 5 for calculating the rotation angle. The rotor 3 has a first rotor pattern 31 with a plurality of unit patterns 310 arranged along the measurement direction around the rotating shaft 2, and a second rotor pattern 32 with fewer unit patterns 320 than the plurality of unit patterns 310 in the first rotor pattern 310 arranged along the measurement direction. The number of the plurality of unit patterns 310 of the first rotor pattern 31 and the number of the plurality of unit patterns 320 of the second rotor pattern 32 are provided such that the maximum common divisor therebetween is two or more. The calculating unit calculates the rotation angle of the rotor 3 based on the detection signals from the first rotor pattern 31 and the second rotor pattern 32.

Abstract: A motor rotation detection device is disclosed. The motor rotation detection device according to one embodiment of the present invention, which is coupled to a rotating shaft of a motor to transmit a rotation position of a motor to a motor position sensor (MPS) through magnetic flux in a non-contact manner, includes: a spacer that is disposed so that one end thereof is in contact with one end of the rotating shaft; a sensor magnet that is disposed on the other end of the spacer and generates magnetic flux; and a case that is coupled to the rotating shaft and provides a fixing force to fix the sensor magnet and the spacer to the rotating shaft.

Abstract: A starter assembly includes a partial planetary gear set connected to a pinion gear slidable along a first axis. The starter also includes a motor casing housing a brushless electric motor and having a first bearing. The motor includes multi-phase stator and rotor assemblies arranged inside the casing concentrically relative to the first axis. The rotor assembly has a rotor with a shaft supported by the first bearing and connected to a sun gear engaging the gear set, and a rotor position and speed sensor target. The starter additionally includes a motor end-cap for mating with and enclosing the motor casing and having a second bearing supporting the shaft. The starter also includes an electronics cover with a power connector for mating with the end-cap and housing an electronic commutator assembly. The commutator assembly includes power electronics, and control processor electronics arranged between the end-cap and the power electronics.

Abstract: A system for determining an absolute position of a device includes a high resolution track (14), a sensor and processing unit (22) associated with the high resolution track (14), a reference track (18) having a plurality of pole pairs arranged to define a single-track Gray code segment, and an array of Hall effect sensors (26) associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the single-track Gray code segment. The sensor and processing unit (22) combines the reference signal with the position of the device over the high resolution track to determine an initial, fine absolute position of the device. An up/down hardware counter (34) increments the initial fine absolute position using a signal generated from the high resolution track, and without any further software-based processing, to maintain and continuously update the fine absolute position of the device.

Abstract: The present invention provides control for synchronous machines in order to achieve an approximately constant torque irrespective of the load angle. The induced voltage of the synchronous machine rotating with a zero-current of the stator is first determined. Starting from the voltage plot of the induced voltage over the load angle, a current plot which achieves a constant torque irrespective of the load angle or any other default settings, can then be calculated. In particular, a non-sinusoidal current plot can also be calculated for non-sinusoidal plots of the induced voltage in the synchronous machine, in order to achieve desired settings that are as constant as possible irrespective of the load angle of the synchronous machine.

Abstract: A magnetic sensor integrated circuit includes a rectifier circuit, a magnetic field detection circuit, and a timing controller. The rectifier circuit converts an external power into a DC power. The magnetic field detection circuit senses a polarity of an external magnetic field and outputting a magnetic detection signal; and the magnetic field detection circuit includes a first chopping switch, a first amplifier unit and a switched capacitor filter module. The timing controller outputs a first clock signal to the first chopping switch and the first amplifier unit, and a second clock signal delayed for the first clock signal with a first predetermined time to the switched capacitor filter module.

Abstract: An elbow harness connected to a forearm harness, the forearm harness supporting a rod driven by a power source, and a proximity detector at a distal end of the forearm harness proximate with where a hand exits the forearm harness when worn. The proximity detector is configured to trigger the power source to drive the rod from a retracted position on the forearm harness to an extended position on the forearm harness.

Abstract: Described embodiments provide an electronic circuit for controlling a motor. The electronic circuit includes a magnetic field sensing circuit responsive to magnetic field sensing elements disposed to sense rotation of the motor. The magnetic field sensing elements generate magnetic field signals, each having a state indicative of at least one of the rotational position and a rotation speed of the motor. A position and speed sensing circuit generates a signal representative of the rotational position of the motor and tracks state changes of the magnetic field signals. A gate driver circuit generates motor drive signals that drive the motor based upon the sensed rotational position. The position and speed sensing circuit generates a qualified control signal based upon a determined valid state change of the magnetic field signals. The gate driver circuit generates the motor drive signals based, at least in part, upon the qualified control signal.

Abstract: The invention relates to a power supply unit for supplying multiple conductor portions (3) of a stator winding of an electric machine which are inserted in respective slots (2), wherein the power supply unit is configured to supply a first conductor portion and a second conductor portion with at least one different operating parameter of a respective current function and/or the power supply unit is configured to supply a conductor portion with at least two superimposed current functions, which in each case have at least one different operating parameter. Furthermore, the invention relates to an electric machine having such a power supply unit.

Abstract: A method according to an exemplary aspect of the present disclosure includes, among other things, detecting a position, including a polarity, of a rotor to detect incorrect rotor position offset of an electric machine without generating torque or motion within the electric machine.

Abstract: A method of determining angular position (A) of a rotor of an N-phase permanent magnet motor (PMM). A processor having an associated stored angular position determination (APD) algorithm is programmed to implement the algorithm to cause an associated motor controller to execute steps including forcing one vector at a time a phase vector set of current or voltage vectors to stator terminals of windings for the N-phases a positive and negative magnitude vector, wherein the vector magnitude is sufficiently small to not move the rotor, and a time duration for the forcing current or voltage vectors is essentially constant. The resulting stator current or voltage levels are measured for each current or voltage vector. An N-dimension current vector or voltage vector is generated from superposition of the resulting stator current levels or resulting stator voltage levels. The N-dimension current vector or voltage vector is used to determine angular position.

Abstract: A power conversion apparatus is equipped with switching devices to perform power conversion of input AC power supplied from an AC power supply to output AC power having a predetermined voltage and a predetermined frequency, and to supply the power to a motor connected thereto. The apparatus includes a controller controlling switching of the switching devices, a capacitor smoothing a ripple generated by the switching of the switching devices, a current controller controlling a current flowing to the motor, and a voltage distortion corrector detecting a harmonic component caused by distortion in motor input power, and superimposing compensation values on an output of the current controller in accordance with a value of the harmonic component.

Abstract: An integrated servo system and a method of controlling a motor is provided. The integrated servo system includes a position detector which determines original position data of a motor and a position signal processor which determines a position of the motor based on the determined position data. The integrated servo system further includes a servo controller circuit which controls the motor based on the determined position data and a parallel bus through which the determined position data is transmitted from the position signal processor to the servo controller circuit.

Abstract: A control apparatus controlling a rotating machine includes a signal output unit that outputs an excitation signal to a resolver used for detecting a rotational angle of the rotating machine; a demodulation unit that demodulate a signal related to the rotational angle based on a detection of a modulated signal and the excitation signal so as to output a demodulated signal; a filter that eliminates higher harmonics in the demodulated signal outputted by the demodulation unit so as to output a calculated angle of the rotational angle; and an operating unit that controls a switching element included in a DC-AC conversion circuit to be ON and OFF based on the calculated angle of the rotational angle outputted by the filter, so as to control the rotating machine with an output voltage of the DC-AC conversion circuit supplied to the rotating machine.

Abstract: Disclosed is an angle detection device including plural sensors that output corresponding sinusoidal signals, wherein each of the sinusoidal signals varies sinusoidally depending on a rotational angle of a rotor of a motor, and each of the sinusoidal signals has a phase that depends on a position of the corresponding sensor; a vector generating unit that generates a vector represented by a result of mutually operating at least two of the sinusoidal signals; a vector rotation unit that rotates the vector by operating the vector and reference sine waves having corresponding phases; and an angle search unit that causes the vector rotation unit to sequentially rotate the vector until a phase of the vector becomes a predetermined phase, and that detects an angle between the vector prior to being rotated and the predetermined phase as the rotational angle of the rotor of the motor.

Abstract: A unit of absolute rotary position encoding, where the angular range of encoding is matched to the number of poles of an electrical motor it is intended that the encoder is to be attached to. The electrical motor is suitably a brushless DC motor. This provides unique rotational position values only through an angle corresponding to an angle between two consecutive poles to enable control/drive electronics to accurately and smoothly turn the rotor from standstill and at low speeds with varying loads applied to the motor.

Abstract: A method and system for measuring rotor position or velocity in an electric motor disposed in hydraulic fluid. The system comprises a contactless position sensor that measures electric motor rotor via magnetic, optical, or other means through a diaphragm that is permeable to the sensing means but impervious to the hydraulic fluid. An electronic sensor is positioned outside the operating fluid, whereas the motor is located in the fluid volume.

Abstract: A detection control system includes a sensing unit, a control module and a driving module for a motor including a rotor and a stator. The sensing unit electrically connects the motor to sense a first and a second magnetic pole of the rotor cross a chip disposed between the rotor and the stator; a third magnetic pole is alternated to a forth magnetic pole of the stator to generate a sensing signal. A detection unit of the control module detects a kickback voltage value generated by a first current value changing to a second current value to calculate a minimum current value to generate a detecting signal. A timing unit receives the sensing and the detecting signal to calculate a first and a second period of time, and a discharging time. The driving module drives the rotor by receiving a control signal the control unit generates by controlling an alternating time.

Abstract: In a method for the determination of a current initial rotational position of a rotor and in an arrangement for carrying out same, an incremental position encoder outputs an output signal. The output signal is produced by superposition of a chronologically random and systematically fluctuating signal interference on a basic signal, and composed of at least two component signals which change periodically in accordance with the rotational position of the rotor and are in a fixed angular relationship to one another. To determine the position, the output signal is used exclusively. The current initial rotational position of the rotor relative to a reference initial rotational position is determined by comparing the time profile of the portion of the systematically fluctuating signal interference of a current measured value sequence of the signal and the measured values of a signal sequence acquired starting from the reference initial rotational position.

Abstract: 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.

Abstract: A powered screwdriver system includes an electric ratchet. In accordance with one aspect, the powered screwdriver system includes a driver housing and includes a motor disposed within the housing. A working end provides a rotational output and is mechanically coupled to the rotor. A power source provides power to the motor. A controller receives signals representative of a motor condition and, based on the received signals, controls the motor in a manner providing the electric ratchet.

Abstract: The present invention is directed to a method of estimating a motor rotation angle that does not affect precision of a detected angle of a crank angle sensor, which is an alternative sensor, when abnormality occurs in a resolver and a peripheral circuit, and performing a motor control without failure of an inverter or peripheral device. A vehicle system includes a motor, a resolver detecting a rotor rotation angle of the motor, a motor control circuit controlling the motor based on information on rotor rotation angle and torque command value, an engine connected to the motor through a crankshaft, and a crankshaft sensor detecting revolutions of the crankshaft, in which the motor control circuit estimates rotor rotation angle based on a variation rate of the number of revolutions of the crankshaft when abnormality of the resolver is detected, and performs a weak field control based on estimated rotor rotation angle.

Abstract: A sensor system for providing control of an electric motor having an inductive angle sensor system including a first inductive coil configured for affixation to a rotor shaft of the electric motor wherein rotation of the rotor shaft causes corresponding rotation of the first inductive coil. A second inductive coil fixedly mounted in spaced relationship to the first inductive coil. An evaluation circuit coupled to the second inductive coil and to the electric motor operative to determine a rotor shaft angle for the rotor shaft of the electric motor through evaluation of an induced magnetic field between the first and second inductive coils.

Abstract: Rotational angle measurement apparatus measuring magnetic-field angle or rotational angle with sufficient accuracy wherein a non-magnetic conductor is arranged in the vicinity of the magnetic flux generator or the magnetic sensor, even when the magnetic flux generator rotates at high speed. The rotational angle measurement apparatus is configured with a magnetic sensor 70 which responds to a magnetic-field angle and a detection unit 302 which inputs an output of the magnetic sensor. The rotational angle measurement apparatus is employed with a rotatable body 121 provided with a magnetic flux generator 202. The output of the magnetic sensor is a raw-angle signal set 155 corresponding to the magnetic-field angle. The detection unit outputs a corrected angle after a non-magnetic conductor in the vicinity of the magnetic sensor is corrected, using a correction value outputted by a correction function with rotational velocity of the rotatable body as an argument.

Abstract: A rotation detector provided in a motor unit according to an embodiment includes a first support and a second support, a pair of magnetic field generator, at least one magnetic field detector, and a first magnetic member and a second magnetic member. The pair of magnetic field generator is provided on the first support in a manner facing the second support, and has opposite polarities. The magnetic field detector is formed by winding a coil around a magnetic element whose magnetized direction changes in the longitudinal direction, and is provided on the second support in such a manner that a longitudinal-direction side of the magnetic element faces the first support. Each of the first magnetic member and the second magnetic member is made of a magnetic material, and covers a longitudinal-direction end of the magnetic field detector facing the first support.

Abstract: An independent drive device for an aircraft, the drive device comprising a motor member, a drive mechanism for driving an aircraft wheel, which is adapted to co-operate with the wheel to drive it for rotation, and a coupling mechanism interposed between the motor member and the drive mechanism to selectively couple the wheel to the motor member. The coupling mechanism comprises two coupling members of complementary shape, comprising a first coupling member that rotates with the drive and a second coupling member that rotates with the motor member. The independent drive device includes measurement device for generating information representative of a relative speed of rotation of the second coupling member and the first coupling member. The drive device is associated with a motor controller that causes the motor to rotate so as to cancel the relative speed of rotation between the coupling members prior to coupling them together.

Abstract: A motor speed determining circuit determining a rotation speed of a motor is provided and a processing of generating motor driving waveform is switched in accordance with the rotation speed of the motor. A resolver signal outputted from a resolver 2 is converted to a digital value by an R/D converter 3, and inputted to a computing circuit of resolver value correction 5 via an R/D conversion interface 4. A current value of a motor M is converted to a digital value by an A/D convertor 8. The computing circuit of resolver value correction 5 computes a resolver correction value of the inputted digital signal and calculates positional data from a corrected resolver value. The computing circuit of motor control computes a current instruction value from a motor current value subjected to digital conversion by the A/D converter 8 and a motor current instruction value etc.

Abstract: A motor includes a sensor magnet having a non-circular contour and a magnet cover fixed to an end portion of a shaft to cover the end portion of the shaft. The magnet cover includes a support portion positioned outside the end surface of the end portion of the shaft. In the support portion, a magnet hole having a non-circular cross section as the sensor magnet and extending in the direction of the rotation axis is provided. The sensor magnet is inserted into the magnet hole and fixed to the magnet hole.

Abstract: A rotation-position detection system according to the present invention is configured with a resolver mounted in a brushless motor and a motor controller. The motor controller outputs an excitation signal to the resolver and an A/D converter thereof alternately applies analogue/digital conversion to a sine wave signal and a cosine wave signal outputted from the resolver so that a rotation position of the motor is calculated.

Abstract: 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.

Abstract: A cycle counter generates a cycle signal which indicates, in the form of a digital value, the cycle of Hall signals H+ and H? that indicate the position of a rotor of a motor to be driven. An up/down counter repeatedly alternates between counting “up” and counting “down” upon detecting phase transitions that occur in the Hall signals, and generates a digital driving waveform signal having a sloping region the slope of which is set according to the cycle signal. A D/A converter receives the driving waveform signal, and converts the driving waveform signal thus received into an analog voltage. A driving unit supplies a driving voltage to the motor according to the analog voltage thus received.

Abstract: Disclosed is an angle detection device including plural sensors that output corresponding sinusoidal signals, wherein each of the sinusoidal signals varies sinusoidally depending on a rotational angle of a rotor of a motor, and each of the sinusoidal signals has a phase that depends on a position of the corresponding sensor; a vector generating unit that generates a vector represented by a result of mutually operating at least two of the sinusoidal signals; a vector rotation unit that rotates the vector by operating the vector and reference sine waves having corresponding phases; and an angle search unit that causes the vector rotation unit to sequentially rotate the vector until a phase of the vector becomes a predetermined phase, and that detects an angle between the vector prior to being rotated and the predetermined phase as the rotational angle of the rotor of the motor.

Abstract: An operating status of a motor in a drive unit is analyzed to extend the life of the motor. A wearable motion assistive device 1 includes a shoulder joint mechanism 5 and an elbow joint mechanism 6 for aiding a movement of the shoulder joint and the elbow joint, and a control unit 100 having a control circuit for controlling drive units 11 for the shoulder and elbow joint mechanisms 5 and 6. The control unit 100 controls the drive units 11 based on a physical quantity and a biosignal detected by an angle sensor, a torque sensor, and a biosignal detecting sensor. A controller in the drive unit 11 includes a motor monitoring unit for monitoring an operational status of the motor, and a motor control unit for limiting a drive signal supplied to the motor based on a monitoring result provided by the motor monitoring unit, in order to prevent an overload state of the motor.

Abstract: In speed control that is performed within a single operating cycle of a printer, three-level control of ON control, OFF control, and chopper control, is performed in place of the two-level control of ON control and OFF control, to effectively suppress speed variations due to load variations within a single operating cycle, even in small printers provided with DC motors having small output torques. In a printer comprising a DC motor 7, a paper feeding unit 5 that includes a paper feeding roller that uses the DC motor as the driving source, and a printing mechanism unit 2, for printing, in use of the printing mechanism unit 2, onto paper that is advanced by a specific amount by the paper feeding unit 5, an encoder 10 for outputting pulse signals according to the rotation of the DC motor 7 is provided.

Abstract: A servo motor control apparatus has a feedback loop. When an oscillation detection signal indicates no detection of oscillation, a parameter operating section gives an updating section an operational instruction to set a control parameter in accordance with a supplied set value. When the oscillation detection signal indicates detection of oscillation, the parameter operating section gives the updating section an operational instruction to set such a control parameter as to narrow a frequency band width of the feedback loop.

Abstract: A door operator with an electrical back check feature is disclosed. Embodiments of the present invention are realized by a motorized door operator that electrically creates a back check force for an opening door. The door operator simulates the back check normally created by hydraulic means in convention door closers, but without the use of pistons, springs or hydraulic fluid. The door operator includes a motor disposed to operatively connect to a door so that the door will open when the motor moves, and a position sensor to determine a position of the door. A processor is programmed to exert a closing force on the door in the back check region. In some embodiments, the closing force is exerted by injecting a voltage into the electric motor of the door operator.

Abstract: There is provided a motor. The motor may include a rotor case including a driving magnet formed on an inner circumferential surface thereof and providing a driving force by interacting with a coil of a stator, a low-speed control magnet formed on an outer circumferential surface of the rotor case and generating a frequency allowing for low-speed rotation enabling label printing as the rotor case rotates at a low speed; and a sensing part sensing an analog signal generated from the low-speed control magnet.

Abstract: A magnetic sensor disposed in an axial direction of a shaft of a motor detects the rotation angle of the rotor by detecting magnetism of the magnet that is disposed on one end of the shaft. A first and second conducting wires extend in parallel with an axis of the shaft, and are equidistantly positioned relative to the axis, on a virtual circle that has a center point on the axis of the shaft. The electric current flowing in the first conducting wire and the electric current flowing in the second conducting wire have the same magnitude and the same flow direction with each other at any time. When the first conducting wire and the second conducting wire are on opposite sides relative to the center point of the virtual circle, the magnetic fields around the conducting wires cancel with each other, thereby enabling accurate detection of the rotation angle.

Abstract: A sensor system for providing control of an electric motor having an inductive angle sensor system including a first inductive coil configured for affixation to a rotor shaft of the electric motor wherein rotation of the rotor shaft causes corresponding rotation of the first inductive coil. A second inductive coil fixedly mounted in spaced relationship to the first inductive coil. An evaluation circuit coupled to the second inductive coil and to the electric motor operative to determine a rotor shaft angle for the rotor shaft of the electric motor through evaluation of an induced magnetic field between the first and second inductive coils.

Abstract: An H-bridge circuit is connected to a coil of the vibration motor that is to be driven. A comparator receives Hall signals indicating position information of a rotor of the vibration motor, and converts to an FG signal. A pulse width modulator generates a pulse-modulated pulse signal specifying energization time of the coil of the vibration motor. The pulse width modulator, in a first mode, after commencing start-up of the vibration motor, sets a duty ratio of the pulse signal to 100%, and after that, switches the duty ratio to a predetermined value in accordance with rotational frequency of the motor. In a second mode, the duty ratio of the pulse signal continues to be set to 100%. In a third mode, frequency and the duty ratio of the pulse signal are set based on a control signal of a pulse form inputted from outside. The control signal is used also in switching mode.

Abstract: An apparatus is disclosed for simultaneously measuring the rotational speed and/or direction of a shaft, and providing control power in accordance with the shaft rotation. The apparatus includes a permanent magnet machine (PMM) having a multipole rotor and a stator. The rotor has a plurality of permanent magnet poles and connection to the rotating shaft; the stator includes a winding and electrical connections, so that motion of the rotor with respect to the stator causes a voltage signal at the electrical connections. The apparatus also includes a circuit including a power conversion portion and a speed/direction sensing portion. The circuit receives the voltage signal from the PMM, and simultaneously outputs control power from the power conversion portion and a signal indicating the rotational speed and/or direction of the shaft from the sensing portion.

Abstract: A control apparatus using a multipole resolver for calculating the rotation angle of a motor includes an acquisition unit, a learning unit, a calculation unit, and a correction unit. The acquisition unit acquires a detected angle ? detected by the multipole resolver. The learning unit learns the waveform of an error Err? for each pole of the resolver. The calculation unit calculates a motor's rotational acceleration variation ?. The correction unit compares the rotation speed variation ? with a threshold value ?0. Where ?<?0, the correction unit performs a normal correction of calculating a corrected angle ? using an error Err? of one mechanical period (in which the motor makes one full rotation) ago. In contrast, where ?>?0, the correction unit performs a transition correction of calculating a corrected angle ? using an immediately preceding error Err?.

Abstract: A multi-phase electric motor including a housing, a stator mounted to the housing, a rotor rotatably mounted relative to the stator, and a position sensing system configured and disposed to output a signal representing a position of the rotor relative to the stator. The position sensing system includes a rotating member mounted relative to the rotor and a plurality of digital sensors mounted relative to the rotating member. At least two of the plurality of digital sensors are configured and disposed to generate a quadrature output signal. The plurality of digital sensors being configured and disposed to sense discrete portions of the rotating member to detect a position of the rotor relative to the stator.

Abstract: A power transistor is arranged between an output terminal and a power supply terminal. A pre-driver includes a high-side transistor and a low-side transistor connected in series between the power supply terminal and a second terminal, and the ON/OFF operations of which are controlled in a complementary manner according to a control signal. The electric potential at a connection node between the two transistors is output to a control terminal of the power transistor. A constant voltage circuit stabilizes the second terminal to a predetermined voltage. An output transistor for the constant voltage circuit is provided between the second terminal and the ground terminal. A differential amplifier adjusts the voltage applied to the control terminal of the output transistor such that the electric potential at the second terminal approaches a predetermined target value. A feedback capacitor is provided between the second terminal and the control terminal of the output transistor.

Abstract: A motor control device that controls the driving of a motor having a permanent magnet provided at a rotor has: an angle detector that detects the angle of the rotor by use of an angle sensor; a current detector that detects, as a detected current, the outflow current from or inflow current to a direct-current power source serving as the source for driving the motor; and an angle corrector that corrects the detected angle based on the detected current. The driving of the motor is controlled by use of a corrected angle obtained through the correction by the angle corrector.

Abstract: A unit of absolute rotary position encoding, where the angular range of encoding is matched to the number of poles of an electrical motor it is intended that the encoder is to be attached to. The electrical motor is suitably a brushless DC motor. This provides unique rotational position values only through an angle corresponding to an angle between two consecutive poles to enable control/drive electronics to accurately and smoothly turn the rotor from standstill and at low speeds with varying loads applied to the motor.

Abstract: A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.