Abstract: The present disclosure provides an inductance detection method includes steps of: (a) acquiring a stator resistance of the reluctance motor; (b) injecting a high-frequency sinusoidal signal in the d-axis or q-axis direction; (c) injecting an align signal command in the q-axis or d-axis direction; (d) receiving a dq-axes signal generated through injecting the high-frequency sinusoidal signal and the align signal command; (e) sampling a motor feedback signal generated through receiving the dq-axes signal; (f) in the direction of injecting the high-frequency sinusoidal signal, calculating an amplitude difference between the high-frequency sinusoidal signal and the motor feedback signal, and adjusting an amplitude of the high-frequency sinusoidal signal according to the amplitude difference for regulating a feedback amplitude of the motor feedback signal; and (g) when the feedback amplitude reaching an expected amplitude, calculating an apparent inductance of the reluctance motor based on the dq-axes signal, the

Abstract: In one aspect of the present invention, there is provided a modular respirator comprising an elongate filter unit having a filter inlet, a filter a filter outlet, and a replaceable fluid filter for filtering pollutants within the fluid. The elongate exhaust unit having an exhaust inlet, an exhaust outlet, and one or more one-way valves. A mask assembly having a mask for covering the oral and nasal passage of a user, a mask inlet at one end of the mask, a mask outlet at an opposite end of the mask, wherein the mask inlet is releasably fastened to the filter outlet, and the mask outlet is releasably fastened to the exhaust inlet.

Abstract: A motor control apparatus includes: an excitation unit configured to excite a plurality of excitation phases of a motor; a measurement unit configured to measure a physical amount that changes according to an inductance of at least one of a plurality of coils that make up the plurality of excitation phases by exciting each of the plurality of excitation phases, and generate measured data that includes measurement values of the physical amount measured for the plurality of excitation phases; and a determination unit configured to determine, based on the measured data, a rotational position of a rotor of the motor and whether or not at least one of the motor and the excitation unit has a failure.

Abstract: A motor current protecting circuit is provided. A voltage calculating circuit determines whether or not each of low-side switches is fully turned on and then determines whether or not a voltage difference between a first terminal and a second terminal of each of the low-side switches being fully turned on is larger than or equal to a zero value. The voltage calculating circuit adds up the voltage differences each of which is larger than or equal to the zero value to output a voltage signal. A control circuit controls a driver circuit to switch the low-side switches and high-side switches according to the voltage signal.

Abstract: A motor control apparatus includes a voltage control unit and a current detection unit. The voltage control unit controls a voltage when applied to cause current to flow through the coils a motor that is detected by the current detection unit. When measurement processing is performed on a set from a plurality of sets of coils having two coils each, a first detection result is obtained by the coil current flowing from a first coil of the set to a second coil of the set. A second detection result then is obtained by the coil current flowing from the second coil to the first coil. The stop position of the rotor of the motor is determined based on the first detection result and the second detection result obtained for each of the plurality of sets of coils.

Abstract: A control unit for a brushless DC motor of a power tool having a rotor and a stator is provided. The control unit detects an initial position of the rotor, commutates the motor beginning at the initial position of the rotor using a low-speed motor commutation scheme until an output speed of the rotor exceeds a speed threshold, and commutates the motor based on a back-electromotive force (back-EMF) voltage of the motor after the output speed of the rotor exceeds the speed threshold. In the low-speed commutation scheme, the control unit applies a first set of voltage pulses to a present sector and a second set of voltage pulses to a next sector, and detects a transition of the rotor from the present sector to the next sector based on motor current measurements associated with the first set of voltage pulses and the second set of voltage pulses.

Abstract: The present disclosure relates to a motor driving method, which includes the following steps: detecting a detected voltage value between a first switch and a second switch in a driving circuit, wherein the driving circuit is configured to control the first switch and the second switch according to a switching frequency to provide a driving current to a motor device; determining a driving current according to the detected voltage value; when the driving current is less than a predetermined value, the first switch and the second switch are turned off for a detection period, wherein the length of the detection period is a fixed value; during the detection period, detecting a back electromotive force to calculate a zero crossing time of the back electromotive force; and adjusting the switching frequency according to the zero crossing time.

Abstract: Systems and methods for sensorless motor control may include a back EMF (electromotive force) observer, an adaptive EMF filter, magnitude compensation, hybrid rotor position and speed determination, rotor position and speed blending, and angle compensation. In order to provide accurate and reliable rotor position and speed estimations for a motor over a wide and varied range of speeds, at low speeds, during speed reversals, and/or in the presence of external forces, loads, or torques, the sensorless motor control may utilize a hybrid rotor position and speed determination that leverages both angle-based and magnitude-based methods. Further, the outputs of the two methods may be blended based on a shaping function to generate a final estimated rotor position and speed. Then, the motor may be more accurately and reliably controlled based on the final estimated rotor position and speed.

Abstract: Provided are a method and system for controlling an electric motor, and a controller. The method comprises: controlling an electric motor to operate in an open-loop manner; determining whether a rotational speed of the electric motor reaches a preset rotational speed; if so, determining whether the absolute value of an angle difference between an open-loop angle and a calculated position angle of the electric motor is greater than a preset angle; and if the absolute value of the angle difference is less than or equal to the preset angle, controlling the electric motor to operate in a closed-loop manner so as to avoid the situation where the electric motor cannot operate stably due to problems such as electric motor speed vibration caused by too large an angle difference between the open-loop angle and the position angle.

Abstract: An image forming apparatus includes a stacking portion, a pickup roller, a motor, an image forming unit, and a controller. Upon receiving an instruction for starting a first image forming job, the controller performs an initial operation of supplying current to a motor winding of the motor in a stop state and determining a phase of the rotor based on the flowing current. Based on the determined phase, the controller supplies current to rotate the rotor from its stop state and holds the rotor at a first phase when the first job ends. Upon receiving start instructions for a second image forming job within a period until a predetermined time elapses from when the rotor is held at the first phase, the controller rotates the rotor without performing the initial operation. The controller stops supplying current to the winding if no instructions are not received for starting the second job.

Abstract: An image forming apparatus includes at least one or more rotary members, a motor configured to drive the at least one or more rotary members, a detection unit configured to detect a current value flowing in the motor, and a display unit configured to display information on a state of the at least one or more rotary members. The current value is detected by the detection unit while the at least one or more rotary members are being driven by the motor. When the current value is a first value, information indicating that the at least one or more rotary members are in an abnormal state is not displayed on the display unit. When the current value is a second value larger than the first value, information indicating that the at least one or more rotary members are in the abnormal state is displayed on the display unit.

Abstract: A driving device includes an inverter to output a voltage to coils, a connection switching unit to switch a connection state of the coils between a Y connection and a delta connection, and a controller. The controller causes the inverter to stop outputting, when the connection state of the coils is the Y connection and a current value of the inverter reaches a first threshold A, or when the connection state of the coils is the delta connection and the current value of the inverter reaches a second threshold B. The first threshold A and the second threshold B satisfy B<?3×A.

Abstract: In a motor control device, a rotational phase detection unit detects a rotational phase of a rotor of a stepping motor, and a driving waveform generation unit generates a driving waveform for driving the stepping motor. An advance angle control unit detects a phase difference (advance angle) between a rotational phase of the rotor and a phase of the driving waveform and controls an amplitude or a period of the driving waveform generated by the driving waveform generation unit to perform advance angle control. The advance angle control unit controls an amplitude of the driving waveform by determining a target advance angle based on a variation (advance angle change rate) of an advance angle with respect to a variation of an amplitude in accordance with a change in the advance angle when the amplitude of the driving waveform is changed.

Abstract: There is provided a driving circuit for a stepping motor, including: a counter electromotive force detection circuit configured to detect a counter electromotive force generated in a coil; a current value setting circuit configured to generate a current set value based on the counter electromotive force; a constant current chopper circuit configured to generate a pulse-modulated signal which is pulse-modulated so that a detected value of a coil current flowing through the coil approaches a target amount based on the current set value; and a logic circuit configured to control a bridge circuit connected to the coil according to the pulse-modulated signal, wherein the driving circuit is configured to output the current set value to outside or to access the current set value from the outside.

Abstract: A transport system includes: a mover having a first magnet group arranged in parallel to a first direction and a second magnet group arranged in parallel to a second direction crossing the first direction; and a plurality of coils arranged in parallel to the first direction so as to be able to face the first magnet group and the second magnet group, and the mover is able to move in the first direction along the plurality of coils by electromagnetic force received by the first magnetic group from the plurality of coils while an attitude of the mover is controlled by electromagnetic force received by the first magnetic group or the second magnetic group from the plurality of coils.

Abstract: A power tool is provided including a housing, a brushless motor disposed within the housing, a power switch circuit that supplies power from a power source to the brushless motor, and a controller configured to receive at least one signal associated with a phase current of the motor, detect an angular position of the rotor based on the phase current of the motor, and apply a drive signal to the power switch circuit to control a commutation of the motor based on the detected angular position of the rotor. If the supply of power to the motor is turned OFF to cause the motor to slow down and is turned back ON while the rotor speed exceeds a speed threshold, the controller electronically brakes the motor for a time interval to measure the phase current of the motor and detects the angular position of the rotor based on the measured phase current.

Abstract: A method of driving a three-phase motor includes, while a first phase is energized, driving a second phase using a first drive function which is sinusoidal. The first phase is switched to a non-energized state and a back electromotive force (BEMF) voltage of the first phase is detected. For at least a portion of a time when the first phase is non-energized the driving of the second phase depends on the output of a second drive function different from the first drive function. The second drive function may be non-sinusoidal and may be a cosine function. The second drive function may drive the second phase when the output of the second drive function is a modulation ratio less than 1. When the output of the second drive function is a modulation ratio greater than or equal to 1 the second phase may be driven to a modulation ratio of 1.

Abstract: A method of operating a Brushless Direct Current Motor (BLDCM), the BLDCM of the type including: a series of concentric independently activated electromagnetic phase coils interacting with a series of permanent magnets to provide relative movement therebetween, the phase coils having temporal periods of activation time and deactivation time, the method including the steps of: (a) activating at least one of the phase coils for a short period of activation; and (b) measuring the voltage response across the phase coil of the deactivated phase coil during the short period of activation to determine the rotor position.

Abstract: A power tool and a control method of the power tool are provided. The power tool includes a rotor and a stator having a first phase winding, a second phase winding and a third phase winding; a power supply module configured to power the motor; a drive circuit configured to electrically connecting the power module to at least two of the first phase winding, the second winding, and the third phase winding; a controller configured to control the drive circuit to connect the first phase winding, the second phase winding, and the third phase winding to the power supply module according to a rotational position of the rotor.

Abstract: A motor driving device includes a PWM signal generating unit, a control unit, a driving unit, a floating point selecting unit and a BEMF detecting unit. The PWM signal generating unit generates an input PWM signal having a duty cycle according to a rotation speed command. The control unit generates a driving signal having multiple phases and an output PWM signal. The floating point selection unit selects a floating phase of the motor that is not turned off, and the BEMF detecting unit receives detects the BEMF of the floating phase during ON times or OFF times of the output PWM signal, so as to output a commutation signal in response to zero crossing events occurring in the BEMF. The control unit controls the BEMF detecting unit to detect the BEMF of the floating phase under the ON times or the OFF times of the output PWM signal.

Abstract: A method for starting an induction machine without residual flux includes: scanning a state of the induction machine with different stator frequencies by controlling a supply voltage applied to the induction machine; determining whether a slip value, being a difference between a rotor frequency and a stator frequency, is within a slip interval; and, when it has been determined that the slip value is in the slip interval, regulating the slip value towards zero and magnetising the machine to the required level.

Abstract: The drive device measures an open-phase voltage in an energization period in pulse width modulation control, and estimates position information of a rotor based on the measured voltage value, to drive the three-phase brushless motor. This drive device is configured so that, when a voltage pulse width of a set duty cycle is less than or equal to a predetermined value, energization with a voltage pulse width of a minimum duty cycle is performed twice in one period of pulse width modulation, and energization with a voltage pulse width of a correction duty cycle is performed twice in next one period of the pulse width modulation, so that energization with a voltage pulse width of a drive duty cycle corresponding to the set duty cycle is performed, on average in two periods.

Abstract: In order to prevent erroneous detection of motor step-out even when the rotational speed of the motor crosses a resonance region of the motor under acceleration and/or deceleration, a motor control device (10) includes a control unit for performing control so as to apply a pulse voltage modulated in pulse width to each of coils of plural phases equipped in a motor (20) and periodically switch the phases of the coil currents flowing through the coils of the plural phases, a back electromotive force measuring unit (126) for providing a stop period for temporarily stopping application of the pulse voltage to a coil of any one phase out of the coils of the plural phases when the direction of a coil current flowing through the coil of the phase switches, and measuring back electromotive force induced in the coil during the stop period, and a step-out state detecting unit for detecting a step-out state when the rotational speed of the motor (20) is not in a resonance region of the motor (20) and the back electromot

Abstract: A synchronous reluctance rotary electric machine of an embodiment includes a shaft and a rotor core. The shaft rotates around a rotation axis. The rotor core is fixed to the shaft, includes four layers of hollow parts having a convex shape toward a radially inner side formed for each pole in cross section, and includes bridges between the respective hollow parts and an outer circumferential surface thereof. Then, in each pole, when a center in a circumferential direction is a pole center, both ends in the circumferential direction are pole ends, and the plurality of bridges are a first layer bridge, a second layer bridge, a third layer bridge, and a fourth layer bridge in order from the pole center toward each of the pole ends, a circumferential width between the second layer bridge and the third layer bridge is set to be greater than a circumferential width between the first layer bridge and the second layer bridge and a circumferential width between the third layer bridge and the fourth layer bridge.

Abstract: A method for controlling a single-coil BLDC motor, the method comprising: monitoring a signal indicative of a time derivative of a phase current through the coil of the BLDC motor during at least one commutation cycle; determining a first moment of the at least one commutation cycle such that at the first moment the absolute value of the time derivative of the phase current is smaller than or equal to a slope threshold; determining a rising edge of a driving signal in a commutation cycle, based on the first moment of that commutation cycle and/or based on the first moment of at least one earlier commutation cycle, and/or determining a falling edge of the driving signal in that commutation cycle based on the first moment of at least one earlier commutation cycle; driving the single-coil BLDC motor using the driving signal.

Abstract: According to an aspect of the present invention, a motor control apparatus includes a first driving circuit connected to a motor first phase winding and having H bridge circuit first switching elements, a second driving circuit connected to second phase winding of the motor and having H bridge circuit second switching elements, first and second pulse generators. a detector, an estimator, and a selector. The first pulse generator generates a first PWM signal having a first level signal and a second level signal. The second pulse generator generates a second PWM signal having a first and a second level signal. The selector selects whether to detect a driving current flowing through the first phase winding or to estimate a driving current flowing through the first phase winding. The first pulse generator generates the first PWM signal based on a driving current value output from the detector or the estimator.

Abstract: A motor control device for a motor includes: an inverter circuit supplying power of a battery to the motor; an inverter input voltage detector detecting an inverter input voltage; and a controller including a drive controller for the motor and an abnormality determination unit for determining power feeding abnormality. The abnormality determination unit determines the power feeding abnormality when the inverter input voltage is lower than a voltage threshold and a current from the battery to the inverter circuit is in a determinable range. The abnormality determination unit determines, based on a motor current electrically conducted to the motor or a rotational speed of the motor, whether the current is in the determinable range. A determination threshold in accordance with the determinable range is set that the inverter input voltage is equal to or higher than the voltage threshold when the power feeding region is normal.

Abstract: A motor drive system and method for controlling an electric motor. The motor drive system includes a plurality of phase lines switchably connected to the electric motor, a plurality of controllable switches, and a controller. The controller is communicatively coupled to the plurality of controllable switches and configured to receive a signal indicative of a rotor speed and a rotor position from the rotor sensor. The controller generates a value expressing a back-electromotive force (back-EMF) as a function of the rotor position with respect to a rotating frame of reference. Based on the rotor position, the controller determines a plurality of phase currents that reduce a torque ripple of the electric motor to approximately zero. The controller actuates the controllable switches to supply the electric motor with the plurality of phase currents.

Abstract: A system for controlling an electric motor is disclosed. The system includes a position sensor configured to measure a physical position of a rotor of the electric motor; and a position estimator. The position estimator is configured to: inject a voltage signal having a predetermined frequency into the electric motor, generate an estimated position of a rotor flux based on a feedback current signal in response to the injected voltage signal, and compensate for an offset between the physical position measured by the position sensor and an actual position of the rotor flux based on the estimated position.

Abstract: The present invention provides a device and a method for changing the operating state of an electric machine to the free-wheeling mode, in which significant excessive increases in voltage can be avoided. In the freewheeling mode, the individual phase connections of an electric machine are disconnected electrically from one another in order to change the electric machine into a safe operating state. According to the invention, only some of the phase currents of the electric machine are evaluated. On the basis of the evaluated phase currents, suitable times for the disconnection of all the phase connections are determined, that is to say even for the phases in which no evaluation of the phase currents takes place.

Abstract: A control circuit controls the operation of a brushless DC (BLDC) sensorless motor having a first terminal connected to a first winding, a second terminal connected to a second winding and a third terminal connected to a third winding. A driver circuit applies drive signals to the first and second terminals and places the third terminal in a high-impedance state. The drive signals include first drive signals at a first current amplitude and second drive signals at a second current amplitude different from the first current amplitude. A differencing circuit senses a first mutual inductance voltage at the third terminal in response to the first drive signals and senses a second mutual inductance voltage at the third terminal in response to the second drive signals. The differencing circuit further determines a difference between the first and second mutual inductance voltages and produces a difference signal that is used for zero-crossing detection and rotor position sensing.

Abstract: A circuit includes a driver circuit having a high side switch device and a low side switch device coupled to a load voltage node and a motor winding output. A controller operates the high side switch device and the low side switch device. The controller operates in a normal mode to supply current to the motor winding output for driving a motor winding when an external power supply is available to supply the load voltage node. In response to detecting a loss of the external power supply, the controller operates the high side switch device and the low side switch device in a boost mode to utilize a back electromotive force (BEMF) voltage from the motor winding to supply current to the load voltage node.

Abstract: A method for estimating operation parameters of a servomotor is described. The method includes the steps of: driving the servomotor to rotate stably at an initial angular velocity; computing d- and q-axis components of an initial voltage when the servomotor rotates at the initial angular velocity; accelerating the servomotor to a predetermined angular velocity according to the initial voltage; and computing at least one operation parameter of the servomotor after the servomotor rotates at the predetermined angular velocity.

Abstract: A coil temperature estimation unit 12 estimates the coil temperature of a motor 1 from the equivalent resistance, heat capacity and thermal resistance of the coil of the motor 1, which are given in advance, from the applied voltage to the motor 1 detected by a voltage detector 17, and from a duty ratio command value input from the outside. When a temperature abnormality deciding unit 13 decides that the coil temperature is not normal, a duty limiter 14 limits the duty ratio command value at a low value and outputs it to a FET driving circuit 15.

Abstract: A sensorless motor controller includes a variable link control, including a radiation-hardened field programmable gate array (FPGA) and a back electromotive force (EMF) decoder circuit. The back EMF decoder infers the position of a rotor of the motor. A filter on the decoder conditions the back EMF signal and has multiple cutoff frequencies which can be dynamically controlled by the FPGA in order to compensate for phase shift in the back EMF signal. The FPGA also controls a variable DC link and its digital speed control loop.

Abstract: Controller for a three-phase brushless D.C. motor has a full bridge circuit and an electronic control unit (ECU). The full bridge circuit has three branches each with switches connected to the motor windings. The switches are driven by signals from the ECU. The drive signals are arranged in two sets of three signals. The two sets are offset by 180 electrical degrees. The drive signals of each set are offset by 120 electrical degrees and each have an active portion, alternating with an inactive portion. The active portion includes an initial interval of pulsed activation, an intermediate interval of continuous activation, and a final interval of pulsed activation. The active portion of the drive signals is greater than 120 electrical degrees, with each initial interval of pulsed activation of a switch overlapping the final interval of the previously activated switch.

Abstract: A circuit includes a processor that analyzes a pulse width modulated (PWM) signal feedback from a brushless DC motor to determine a transition between a mutual inductance zero crossing condition and a Back Electro Motive Force (BEMF) zero crossing condition of the brushless DC motor. A mutual inductance controller is executed by the processor to commutate the brushless DC motor at startup of the motor when the mutual inductance zero crossing condition is detected by the processor. A BEMF controller is executed by the processor to commutate the brushless DC motor after startup of the motor when the BEMF zero crossing condition is detected by the processor.

Abstract: Methods and apparatus for determining rotor position in a motor including a rotor and stator windings. The method includes measuring inductive sense values for each pair of the stator windings by performing an inductive sense routine on the motor, measuring stator winding voltage values, induced by mutual inductance between windings, for each of the stator windings by performing a mutual inductance sensing routine on the motor, and determining the rotor position based on the inductive sense values and the stator winding voltage values.

Abstract: An amount of a motor drive current is controlled to an appropriate value. Two coils are provided, and a rotor is rotated by the coils by setting different phases for the supplied currents to the two coils. During a phase where one of the coils is in a high-impedance state, an induced voltage generated in the coil is detected. According to the state of the induced voltage, an output control circuit controls the amounts of the motor drive currents supplied to the two coils.

Abstract: A mobile high-frequency antenna rapidly adjustable to minimize VSWR and maximize transmitting and receiving efficiency includes a conductive whip mounted on a coil housing containing a solenoidal loading coil electrically connected at an upper end to the whip and at a lower end to a conductive mast which supports the coil housing. A coil contactor disk at the upper end of a conductive metal shaft raised or lowered by a stepper motor-driven lead screw has protruding spring loaded balls which rollingly contact inner surfaces of coil turns to thus insert less or more inductance between the shaft and whip to tune the antenna. A pair of RF de-couplers in a coil housing base plug which electrically contacts the mast and the lower end of the coil slidably support and electrically contact the shaft, thus shorting out lower parts of the coil to suppress harmonic currents from being induced therein.

Abstract: Motor drives and control methods are presented for sensorless motor speed control in which inverter output currents are sampled from the inverter output, and a frequency modulation value is determined based on the current feedback and either one or more voltage commands or one or more voltage feedback signals. A speed or frequency setpoint is adjusted at least partially according to the frequency modulation value to provide an adjusted frequency or speed setpoint value that is then used in controlling the inverter to provide stability control to mitigate hunting or motor stoppage.

Abstract: A motor control apparatus includes: a supply unit configured to supply a current for excitation to a plurality of coils of a motor; a first detection unit configured to detect a physical quantity which varies depending on a change in inductance of at least one of the plurality of coils; a determination unit configured to determine a rotational position of a rotor of the motor based on the physical quantity detected by the first detection unit; and a control unit configured to control the rotational position of the rotor of the motor based on a determination result by the determination unit.

Abstract: A vehicle having a traction battery and at least one electric machine for propelling the vehicle is provided. A high voltage DC bus electrically connects the traction battery to the electric machine. A controller monitors and commands power flow through the DC bus, the electric machine, and the battery. In response to a key-off event, the controller immediately discharges the DC bus by providing a current to the electric machines. This discharge continues until the voltage on the DC bus reaches a threshold. As the speed of the electric machine decreases towards a speed threshold, the voltage in the DC bus is maintained. Once the electric machine speed reduces past the threshold, the DC bus discharges the remaining voltage in the DC bus at a rate slower than the first immediate discharge.

Abstract: A sensorless brushless motor control device includes a first amplification module common to all motor phases and generating an intermediary voltage signal, a voltage divider between each motor phase and a node on which the intermediary voltage signal is generated, and a computation unit. Each voltage divider generates a first corrected electromotive force with a predetermined average value. The computation unit controls the motor on the basis of the first corrected electromotive forces. By using only hardware components, the control device maintains the average of the corrected electromotive forces at the center of the analog acquisition zone of the computation unit.

Abstract: A motor driving apparatus includes an automatic gain control circuit on a signal path for transmitting a rotor-position detecting signal (hall voltage signal), and the automatic gain control circuit includes: an amplifier, configured to perform differential amplification on an input signal (step-angle hall current signal) to generate an output signal (amplified hall current signal); and a feedback control portion, configured to monitor the output signal (monitored current signal) to decide a gain of the amplifier.

Abstract: There are provided a motor driving apparatus and method, the motor driving apparatus including: a filter controlling unit detecting a frequency of a pulse width modulation (PWM) signal and generating a control signal; a first filtering unit filtering a back electromotive force (BEMF) signal according to the control signal; a second filtering unit filtering a reference signal according to the control signal; and a comparing unit comparing output of the first and second filtering units and generating a motor rotor detection signal.

Abstract: A brushless motor driving apparatus that rotates and drives a brushless motor, which has a plurality of coils, by switching energization modes corresponding to phases of the brushless motor, sequentially switches the energization modes based on a non-energized phase voltage and a voltage threshold. Also, the brushless motor driving apparatus regulates an upper threshold for energization amount based on the voltage threshold and a change in the non-energized phase voltage at timing of switching the energization mode.

Abstract: The laundry treatment machine, absent a position sensor to sense the rotor position of a motor, includes a driving unit having an DC/AC inverter, an voltage detection unit to detect output voltage, and an inverter controller to control the inverter. The output voltage detection unit includes a plurality of resistors connected between the inverter and the motor and a comparator to compare voltage detected by some of the resistors with reference voltage and to detect pulse width modulation (PWM)-based output voltage. The voltage detection unit outputs the PWM-based output voltage output from the comparator to the inverter controller in a first mode in which at least one switching device of the inverter is turned on. The voltage detection unit outputs voltage detected by other some of the resistors to the inverter controller in a second mode in which all switching devices of the inverter are turned off.

Abstract: A controller for a brushless direct-current motor having an upstream converter, which has a half-bridge having a pair of switching means for each phase winding of the motor, includes a measuring device or has a signal connection to a measuring device. The measuring device is associated with a half-bridge and by means of the measuring device, the induced voltage, the counterelectromotive force of a phase winding, can be detected for rotor position detection in the current-free state, for which purpose the controller, in an operating mode that causes the braking and in which the switching means cause a short circuit of the phase windings, briefly opens the switching means associated with the measuring device in order to determine a rotor motion.

Abstract: A circuit configuration for driving an electric motor includes a signal evaluation module, which stores a number of output patterns. An input pattern is specified, and as a function of the input pattern, one of the output patterns is output, by which the electric motor is driven.