Abstract: A power tool includes a housing, a brushless DC motor housed inside the housing, a power supply, a control unit, and an input unit such as a trigger switch actuated by a user. The control unit controls the commutation of the motor through a series of power switches coupled to the power supply. The control unit initiates electronic braking of the motor after occurrence of a condition in the input unit, such as trigger release or reduced speed, indicative of the power tool shut-down. A mechanism is provided to power the control unit for a predetermined amount of time after the detection of the condition from the input unit in order to complete the electronic braking of the motor.

Abstract: A first motor controller generates commanded speeds of a first rotor of a first electric motor for a first time interval and a second time interval. A first speed monitor detects observed speeds of the first rotor for the time intervals. A first ratio is determined based on a relationship between respective commanded speeds and corresponding observed speeds for the first time interval and the second time interval. A first data processor increments a persistence counter for the first motor if the first ratio increases or changes during the time intervals. A first motor deceleration is estimated if the persistence counter exceeds a stall limit count. A target rotor speed of a second motor is adjusted based on the estimated first motor rate of change to track the first motor rate of change (or first rotor speed) if the persistence counter exceeds the stall limit count.

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 fan rotary speed controlling device includes a first signal generating circuit, a second signal generating circuit, a pulse width modulation (PWM) circuit and a switching circuit. The first signal generating circuit receives a real frequency signal and a target frequency signal, and generates a first signal according to the real frequency signal and the target frequency signal. The second signal generating circuit generates a second signal according to the first signal. The PWM circuit generates a PWM signal according to the second signal. The switching circuit is electrically connected with the PWM circuit and outputs a control signal to control the rotary speed of the motor. Hence, the fan rotary speed controlling device boosts the accuracy and the stability of the fan rotary speed.

Abstract: A control circuit controls an electric motor and includes: a measuring device configured to measure a first phase current of the motor and provide a corresponding first analog signal; an analog-to-digital converter structured to convert the first analog signal into a first digital signal; a conversion module for generating a first converted digital signal representative of the first digital signal expressed in a rotating reference system; a node structured to compare the first converted digital signal into a first reference signal and generate a first error signal; and a measure control circuit structured to provide a timing signal of the analog-to-digital converter depending on the first error signal and a time delay introduced by the measuring device.

Abstract: A modularized control circuit with a signal-capturing function for a fan motor is disclosed. The modularized control circuit includes a driven circuit and a microcontroller integrated circuit. The driven circuit is electrically connected to the fan motor to produce at least one analog driven voltage signal, thus driving the fan motor. The microcontroller integrated circuit is electrically connected to the driven circuit and includes a signal-capturing module, a control unit, and a driven signal generator. The signal-capturing module receives an external pulse signal to produce a cycle-capturing signal. The control unit is connected to the signal-capturing module and receives the cycle-capturing signal to produce a control signal. The driven signal generator is connected to the control unit to receive the control signal, thus producing a plurality of switch driven signals for controlling the driven circuit.

Abstract: A carrier generating unit applies a carrier that monotonically decreases to a switching control unit during either one of a first period that is a period immediately following a period in which a voltage command value is a value not more than a minimum value of the carrier, the voltage command value taking a first predetermined value larger than the minimum value of the carrier in the first period, and a second period that is a period immediately preceding a period in which the voltage command value is not less than a maximum value of the carrier, the voltage command value taking a second predetermined value smaller than the maximum value in the second period.

Abstract: Disclosed herein is a motor driving circuit including: a duty ratio detection unit that detects a duty ratio of input pulse-width-modulation applied to control a speed of a motor; and a driving control unit that detects an output duty ratio corresponding to the duty ratio of the input pulse-width-modulation by using relationship data between the duty ratio of the input pulse-width-modulation and an output duty ratio that are previously stored and controls a duty ratio of a driving signal applied to the motor according to the output duty ratio. By this configuration, a speed of the motor can be accurately controlled.

Abstract: Disclosed herein is a motor driving circuit including: a duty ratio detection unit that detects a duty ratio of input pulse-width-modulation applied to control a speed of a motor; a speed detection unit that detects the speed of the motor; and a driving control unit that detects a targeted speed corresponding to the duty ratio of the input pulse-width-modulation by using relationship data between the duty ratio of the input pulse-width-modulation and the targeted speed that are previously stored and controls a driving of the motor so that the speed of the motor is equal to the targeted speed. By this configuration, a speed of the motor can be accurately controlled.

Abstract: A control device for performing PWM control of an inverter includes a synchronous PWM control circuit for generating a control command for the inverter by performing PWM control based on a comparison between a sinusoidal voltage command signal for operating the AC motor according to, an operation command and a carrier signal, and a carrier generating unit for keeping an integer as a synchronization number being a frequency ratio between the voltage command signal and the carrier signal, and producing the carrier signal by switching the synchronization number according to an operation state of the AC motor. The carrier generating unit adjusts a phase relationship between the voltage command signal and the carrier signal according to the synchronization number such that an AC current transmitted between the inverter and the AC motor according to the control command provided from the synchronous PWM control circuit is symmetrical with respect to a boundary between positive and negative portions.

Abstract: A system to control an asynchronous tri-phase motor may include a braking resistance coupled to receive output voltage from the voltage multiplier to dissipate energy when the system is in a braking mode. The system may further include a module to emit a pulse train (e.g., Pulse Width Modulation (PWM)) and having a frequency selectively determined by a microcontroller. The module may be operatively coupled to apply the pulse train to an H bridge circuit in the IGBT module, which is coupled to pass a conditioned line voltage to the tri-phase motor in response to the PWM pulse train applied to the H bridge circuit in the IGBT module.

Abstract: Disclosed is a system and a method for controlling torque of induction motor in electric vehicle. The system and method for controlling torque of induction motor in electric vehicle according to the present disclosure has an advantageous effect in that torque control problems caused by saturation of magnetic flux, parameters of induction motor and changes in battery voltages during control of torque in the induction motor can be solved using a look-up table (a type of data table), thereby enhancing accuracy in torque control and improving travel performance and fuel efficiency of the electric vehicle.

Abstract: A fan delay control circuit includes a fan connector connected to a fan of an electronic device, a power supplying module connected to the fan connector, and a rotational speed controlling module connected to the power supplying module. The power supplying module is connected to a fan power source and a stand-by power source. The power supplying module may continue to supply power to the fan when the electronic device including the fan is powered off. The rotational speed controlling module includes a square wave generation circuit which generates a square wave signal to control a rotational speed of the fan even when the electronic device is powered off.

Abstract: A drive motor control apparatus for a vehicle, wherein the vehicle has a motor and rotation detecting unit. In the apparatus, the first difference computing unit computes one of multiple first differences every time an actual detected angle of rotation of the motor becomes a corresponding representative angle during the one cycle. The first difference indicates an advancing amount of an estimated angle relative to the actual detected angle. The second difference computing unit computes multiple second differences based on the first differences of the one cycle. The second differences are adjusted in accordance with a degree of acceleration and deceleration of the motor. The adjusted second differences are used for correcting the actual detected angle of rotation of the motor.

Abstract: A fan rotary speed controlling device includes a base voltage generating circuit, a first voltage generating circuit, a second voltage generating circuit and a compensation controlling circuit. The base voltage generating circuit receives a pulse width modulation signal and outputs a base voltage signal. The first voltage generating circuit receives the pulse width modulation signal and generates a first voltage signal according to the pulse width modulation signal. The second voltage generating circuit receives a fan rotary speed signal and generates a second voltage signal according to the fan rotary speed signal. The compensation controlling circuit outputs a voltage deviation compensation signal according to the first voltage signal and the second voltage signal. Hence, the fan rotary speed controlling device provides a stable rotary speed.

Abstract: A circuit arrangement is provided for supplying an electric drive, to which at least two electric energy sources can be connected. At least one of the at least two electric energy sources supplies at least intermittently the electric drive by way of at least one actuating element. At least one electric energy source can be disconnected from the electric drive by way of a switch. Furthermore, a method for operating the circuit arrangement, as well as a motor vehicle including the circuit arrangement, are provided.

Abstract: A brushless motor controller is disclosed. The brushless motor controller includes a control unit and a drive timing generation unit. The control unit detects a load state of the motor. The drive timing generation unit generates a normal energizing timing determined by the rotational position of the rotor. Also, the drive timing generation unit generates an advancing angle energizing timing determined by the rotational position of the rotor and advanced by a predetermined amount from the normal energizing timing, generates a delay amount that changes in correspondence with the detected load state of the motor and the rotational speed of the rotor, and generates a final advancing angle energizing timing delayed by the delay amount from the advancing angle energizing timing.

Abstract: A pulse width modulation (PWM) module is configured to adjust the input PWM control signal and the motor can be implemented in different rotation speed to enhance the flexibility of the implementation of the motor when the PWM control signals are the same. In addition, the PWM modulation block in the present invention includes a PWM direction control circuit, a PWM vector transfer circuit and a PWM signal generation circuit. Apparently, the PWM modulation block of the present invention is connected to a PWM control signal inputted by an external system and an external adjustment apparatus; by setting up the adjustment apparatus, the vector and the modulation direction of the PWM control signal can be adjusted, and the duty cycle of the PWM control signal can also be adjusted.

Abstract: An electric power converter includes a control unit outputting a PWM signal, a bridge circuit producing AC electric power supplied to a motor by turning semiconductor switching devices in the bridge on and off in response to PWM signals, a cut off unit cutting the PWM signals off from the bridge circuit in response to a gate signal, and a monitoring unit generating a test signal for checking the cut off unit. The cut off unit includes a switching circuit switching between the test signal and an external cut off signal, and a delay circuit that delays the output of the switching circuit. The arrangement enables the electric power converter to monitor as to whether the cut off unit is abnormal without stopping the operation of the electric power converter.

Abstract: A motor control circuit for a motor is provided. The motor control circuit drives the motor based on torque command data. The torque command data is output by adding speed error data output from a speed error detecting section based on a first reference clock and a speed pulse and phase error data output from a phase error detecting section based on a second reference clock and the speed pulse. Each of the speed error data and the phase error data is output within a detection range set by a setting section provided for each of the speed error detecting section and the phase error detecting section.

Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.

Abstract: A motor load control apparatus capable of suppressing heat generation of an electronic switch and suppressing occurrence of noise associated with rotation of a fan and vibration of the fan is provided. A switch section (17) in which a first electronic switch (T1) and a second electronic switch (T2) are connected in parallel is provided, and the first electronic switch (T1) is driven by a PWM signal with a predetermined duty ratio and a predetermined frequency and the second electronic switch (T2) is driven in a state of delaying the PWM signal by which the first electronic switch (T1) is driven by a predetermined time. Consequently, as compared with the case of one electronic switch, a heating value of each of the electronic switches can be reduced and radiation measures of the whole apparatus can be reduced. Further, noise or vibration occurring by PWM control can be reduced by changing delay time at random.

Abstract: A data processor establishes a first range of rotational speeds of a rotor of the motor from a first lower limit to a first higher limit and a second range of rotational speeds from a second lower limit to a second higher limit. A hysteresis band or a rotational range of speeds is established such that during operation in the first range the first higher limit is adjusted (e.g., raised by a first amount to be greater than the second lower limit). A sensor detects or measures a rotational speed of a rotor of the motor. The data processor determines whether the measured rotational speed falls within the first range or the second range, as adjusted by the hysteresis band, to identify a selected speed range. A switching frequency of a pulse-width modulation signal is varied in accordance with the selected speed range.

Abstract: A drive system, for a multi-phase brushless electric motor comprising a plurality of phases, comprises: a drive circuit including switch means arranged to vary the phase voltage applied to each of the phases so as to switch the motor between a plurality of active states; and control means. The control means is arranged to control the switch means so as to provide PWM control of the phase voltages to control the mechanical output of the motor. The control means is arranged to define a sequence for all of the active states and, for each PWM period, to allocate state times for the states required for that period to generate a desired net voltage, and to order the required states in the same order as they occur in the sequence.

Abstract: A method and an arrangement are disclosed for identifying one or more parameters of an induction machine when the induction machine is connected to the output phases of a voltage source inverter and the induction machine is in standstill state. The method can include a first phase for magnetizing the machine by providing a first DC magnetization current until the induction machine reaches steady state, the current reference of the inverter having a first value (idc—ref1). A first maximum value (imz—max) of the stator current (isd) is measured during a zero voltage vector. In a second phase, the machine is magnetized by providing a second DC magnetization current, the current reference having a second value (idc—ref2) which is higher than the first reference (idc—ref1). A second maximum value of (isdz—max) the stator current is measured during a zero voltage vector, and a parameter of the induction machine is estimated when the measured first and second maximum values are equal.

Abstract: Systems, methods and computer program products for reducing or removing current spikes generated during a current recirculation period associated with phase switching in a spindle motor are described. In some implementations, the duty cycle of the drive signals applied to the windings of the spindle motor can be adjusted to reduce or eliminate the current surge resulting from current recirculation. In some implementations, the duty cycle of the drive signals during spin-up can be reduced based on a current limit, and the reduced duty cycle can then be used to drive the spindle motor taking into account of current surges in the supply current.

Abstract: A method to permit a start time of a heat engine of a vehicle to be controlled. The heat engine is mechanically coupled to a polyphase rotary electrical machine connected to an on-board electrical network. The method is of the type consisting of carrying out pre-fluxing by establishing an excitation current in the inductor for a predetermined pre-fluxing time (Tpref) before the phase currents are established. In accordance with the method, the predetermined pre-fluxing time (Tpref) is a function of the voltage (Vbat+X) of the on-board electrical network. Typically, the predetermined pre-fluxing time (Tpref) is increased when the voltage (Vbat+X) of the on-board electrical network reduces within a nominal voltage range (V 1, V2).

Abstract: Proposed is a driver having dead-time compensation function. The driver having dead-time compensation function generates an output voltage according to a voltage command and a frequency command. The driver includes an inverter, an output current detector and a control unit. The inverter receives a DC voltage and operates with a pulse width modulation mode so that the driver outputs the output voltage and an output current. The output current detector detects the current value of the output current to generate a output current detecting signal. The control unit outputs a switching control signal to inverter according to the voltage command and the frequency command. The control unit corrects a reference command according to dead-time and the output current detecting signal related to the output current so that amplitude and waveform smoothness of the output voltage and the output current are compensated.

Abstract: The present invention provides a method for driving a three-phase motor with a driver. The driver can provide a pulse-width modulated driving signal and a linear driving signal. The three-phase motor has a first leg, a second leg and a third leg. The method includes: connecting the second leg to the driver; floating the third leg; driving the second leg with the pulse-width-modulated driving signal from the driver; estimating a time when a voltage in the third leg will reach a predetermined threshold; and driving the second leg with the linear driving signal during that time.

Abstract: Disclosed herein is a method of controlling the current of a high-speed Switched Reluctance Motor (SRM) using an inverter circuit including a first switching element, a second switching element, a first diode, a second diode and a reactor, wherein the first switching element and the first diode, the second diode and the second switching element are connected to a bridge circuit, and one end of the reactor is connected to the junction of the first switching element and the first diode, and the remaining end of the reactor is connected to the junction of the second diode and the second switching element; and excitation mode, free-wheeling mode-1, the excitation mode, and free-wheeling mode-2 are sequentially performed in a unit period T, and, when the control is terminated, demagnetization is performed.

Abstract: A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited in advance of zero-crossings of back emf in the winding by an advance angle, and the winding is freewheeled over a freewheel angle. The method then includes varying the advance angle and the freewheel angle in response to changes in the voltage used to excite the winding. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

Abstract: A pulse width modulation (PWM) module is configured to adjust the input PWM control signal and the motor can be implemented in different rotation speed to enhance the flexibility of the implementation of the motor when the PWM control signals are the same. In addition, the PWM modulation block in the present invention includes a PWM direction control circuit, a PWM vector transfer circuit and a PWM signal generation circuit. Apparently, the PWM modulation block of the present invention is connected to a PWM control signal inputted by an external system and an external adjustment apparatus; by setting up the adjustment apparatus, the vector and the modulation direction of the PWM control signal can be adjusted, and the duty cycle of the PWM control signal can also be adjusted.

Abstract: In order to automatically detect a mechanically commutated DC motor, it is provided to acquire an electrical engine size, to determine current ripples in the engine size, to evaluate the amplitude, the duration and/or time position of the detected current ripples and to compare to known ripple patterns, and to choose from a known key data table a number of key data assigned to a certain engine type, when the amplitude, during and/or time position of the detected current ripples correspond to a ripple pattern, which is assigned to the engine type.

Abstract: An anti-noise method for the Direct Current Brushless motor System, which includes a startup circuit, phase detective circuit, motor phase commutation circuit, driving circuit, BEMF detective circuit, and frequency detector, utilizes the BEMF detective circuit to detect the BEMF induced from the coils of the outer motor, and utilizes the sampled voltage phase to determine rotation speed and phase of the external motor by the phase detection circuit and frequency detector. Further, the sampling voltage of the BEMF detection circuit is feedback controlled by the frequency detector, utilized to keep good BEMF to noise ratio, and avoids the BEMF sampling error from the system.

Abstract: A brushless DC motor driving system, in which the duty cycle of the PWM control signals for the duty cycle generator is determined by a speed control circuit, a feedback comparator, and the set and reset signals of a S-R Flip-Flop, wherein the PWM control signals pass through the Hall synthesis circuit, the logic control circuit to drive the coil by the drive current generated, and the duty cycle of the PWM control signals is further adjusted by means of the feedback sensing voltage obtained from the driving current and sensing resistance and fed back to the feedback comparator, the stability and linear stability of the input voltage and the driving current being achieved.

Abstract: A rotary electric machine controller including a current detector detecting rotary electric machine currents generated in a rotary electric machine, a position estimation mechanism outputting an estimated position in accordance with the rotary electric machine currents; a controller outputting voltage commands in accordance with the estimated position; a pulse-width modulator outputting logic signals which are pulse-width modulated in accordance with the voltage commands and with a switching cycle used for pulse-width modulation control; and a voltage application mechanism applying AC voltages for driving the rotary electric machine in accordance with the logic signals. The voltage commands output by the controller are obtained by superimposing, on fundamental voltages for driving the rotary electric machine, position detection voltages which each have a cycle equal to m times of the switching cycle and which are different in phase among respective phases.

Abstract: A control system for an electric machine, the control system including a position sensor and a drive controller. The drive controller generates one or more control signals for exciting a winding of the electric machine in response to edges of a signal output by the position sensor. The times at which the control signals are generated by the drive controller are corrected by a position-sensor offset that is fixed over an operating speed range of the electric machine.

Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.

Abstract: The present invention provides an improved current regulator for PWM based drives for electric motors. The invention provides compensation for the rotor position signal for delays introduced due to the PWM algorithm and for digital sampling present in such a drive. Current regulator commonly operate in a two-phase reference frame, requiring forward and reverse coordinate transformations between the physical current values and the two-phase reference frame variables. The present invention provides an improved compensation in the forward transformation by determining the phase lag between the commanded voltage reference and the output voltage reference and by further compensating the forward transformation for errors introduced due to sampling the current either at different sampling instances than the rotor position or at multiple sampling instances during a carrier period.

Abstract: An apparatus and a method for detecting a lock error in a sensorless motor are disclosed, where the apparatus includes a multiplexer, a negative booster, a comparator and a timer. The multiplexer can receive a coil voltage from the sensorless motor. The negative booster can receive a neutralizing voltage from the sensorless motor and drop the neutralizing voltage. The comparator can compare the coil voltage with the dropped neutralizing voltage for outputting a zero-crossing signal. The timer can count time duration during the zero-crossing signal maintained at the a logic level and determine the lock error in the sensorless motor when the time duration exceeds a predetermined period.

Abstract: In BLDC motors driven via sensorless techniques, the BEMF signals in the motor coils may be used to detect the position of the motor such that speed of the motor may be accurately controlled. When detecting the BEMF signals, however, small perturbations occur which negatively impact the rotational torque of the motor. As a result, torque ripple may occur at regular intervals which may result in inefficiencies as well as audible noise. In various embodiments as described herein, the sampling of the BEMF signals may be done so at pseudo-random intervals such that the overall spectral energy that presents from the BEMF detections may be reduced at specific frequencies (such as fundamental sampling frequencies and harmonics thereof) and spread out over many more frequencies. Thus, despite the overall spectral energy being the same, the amplitude of any given frequency is lower as the sampling of the BEMF is less periodic.

Abstract: A method for detecting a regulating variable of a mechanically commutated DC motor in a positioning device for a motor vehicle is provided. The DC motor has a standard ripple pattern, which contains per engine cycle or semi-cycle at least one index ripple, which is classified with regard to amplitude, duration and/or time position. The counter-electromotoric power is calculated from a measured motor current and the measured motor voltage by a motor model. An alternating element corresponding to the current ripples is extracted from the counter-electromotoric power, which in turn is used to determine the current ripples. Further, in at least one engine cycle or engine semi-cycle the index ripple is identified and the total identified current ripples are counted. The result of the count is hereby corrected when the index ripple is not counted at the expected position.

Abstract: A power supply control device turns off energization of coils from a power supply device when a rotational speed of a motor reaches 500 rpm. After elapsing of one electrical cycle from the time of starting the turning off of the energization, a comparator of a correction device outputs a comparator signal, which is obtained by comparing a voltage of a neutral point of the coils and an induced voltage of the coil. An EX-OR circuit outputs an EX-OR signal, which is an exclusive OR value of the comparator signal and an output signal of a Hall sensor. A sensing unit obtains an electrical angle of a period, during which the EX-OR signal is in a H-level. A difference between the obtained electrical angle and a standard electrical angle of 30 degrees is stored as a correction data value. Thereafter, energization of the coils is restarted.

Abstract: A motor-driving-circuit comprising: a first to-fourth-transistors; a drive-control-circuit to control a energization-state of a motor coil so as to be a driving-state where either one group of groups of the first-and-fourth-transistors and the second-and-third-transistors is on and the other group is off, or so as to be a regeneration-state where the first-and-third-transistors are off and the second-and-fourth-transistors are on; a set-current-detection-circuit; an overcurrent-detection-circuit; and an overcurrent-protection-circuit to output a regeneration-instruction-signal for shifting the energization-state to the regeneration-state if an overcurrent-state does not occur and output a drive-stop-signal for stopping driving the coil if the overcurrent-state occurs, when a current amount flowing through the coil has reached a set-level in the driving-state, the drive-control-circuit shifting the energization-state to the regeneration-state to be maintained for a predetermined time period and thereafter retu

Abstract: Circuitry for controlling a motor, such as a brushless motor (BLM), is disclosed. The circuitry may comprise one or more inputs for receiving rotor position signals from one or more Hall effect sensors that detect the position of, for example, a BLM rotor. The circuitry may also comprise an input for receiving a pulse width modulated speed control signal. The circuitry generates one or more drive signals, each drive signal having a plurality of driving intervals. Each drive signal may control power switches during its driving intervals, the power switches being coupled to electromagnets of the BLM. The circuitry may cause the driving intervals of a first drive signal to be temporally spaced from the driving intervals of a second drive signal.

Abstract: An inverter includes a voltage command generator generating a voltage command value according to an externally specified voltage value, a PWM signal generator generating a PWM signal according to the voltage command value and frequency command value, and a switching unit generating a three-phase AC power according to the PWM signal. The voltage command generator decreases the voltage command value if the output current increases, to prevent the rotation speed of a prime move from suddenly changing. If the output current exceeds a preset upper current threshold, the voltage command value is clamped at a preset minimum output voltage, thereby securing the minimum output voltage for an increase in the output current.

Abstract: A washing machine and a method for controlling the same are disclosed. The washing machine detects a back electromotive force of a washing motor, and controls output of an alarm sound by analyzing periodicity of a waveform period of the back electromotive force. The washing machine determines whether a child or pet is in a drum washing machine on the basis of the back electromotive force generated from the washing motor, and informs a user or guardian of the determined result.

Abstract: Disclosed is a signal transmission circuit device (200) including a feedback signal transmission unit (210) that feeds back a control output signal (Sout) as a feedback signal (Sf) to an input side circuit (200A). A logical comparison circuit (212) detects “mismatch” between input and output by performing logical comparison between a control input signal (Sin) and the feedback signal (Sf). When a state of “mismatch” between input and output occurs, a first pulse generating circuit (202) or a second pulse generating circuit (204) outputs a first correction signal (Sa1) or a second correction signal (Sa2) corresponding to a potential (high level or low level) of the control input signal (Sin), and corrects the control output signal (Sout) to the same potential (high level or low level) as the control input signal (Sin). With such configuration, the mismatch between input and output can be automatically corrected.

Abstract: A data processor establishes a first range of rotational speeds of a rotor of the motor from a first lower limit to a first higher limit and a second range of rotational speeds from a second lower limit to a second higher limit. A hysteresis band or a rotational range of speeds is established such that during operation in the first range the first higher limit is adjusted (e.g., raised by a first amount to be greater than the second lower limit). A sensor detects or measures a rotational speed of a rotor of the motor. The data processor determines whether the measured rotational speed falls within the first range or the second range, as adjusted by the hysteresis band, to identify a selected speed range. A switching frequency of a pulse-width modulation signal is varied in accordance with the selected speed range.

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.