| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 318400350 | With zero-crossing detection (e.g., polarity reversal, etc.) | 66 |
| 20080211440 | MEASUREMENT OF SPEED AND DIRECTION OF COASTING PERMANENT MAGNET SYNCHRONOUS MOTOR - A method for determining the speed of rotation of an unpowered, coasting electric motor, driven, when powered, by an electronic inverter, and without activating switches of the inverter. The steps include determining an electrical frequency of a back emf signal generated at a terminal of the motor or switching node of the inverter when the motor is coasting and determining the mechanical motor frequency and thus speed of rotation by dividing the electrical frequency by the number of motor pole pairs. | 09-04-2008 |
| 20080265817 | SENSORLESS SPEED DETECTION DURING ZERO VECTOR - A speed estimation method for determining the speed of a sensorless permanent magnet brushless motor having one or more phases driven by one or more stages of an inverter, each stage including high- and low-switches connected in series across a DC Bus and having a respective common switched node, the respective switched node being coupled to a respective motor phase terminal. The method includes the steps of applying an alternating sequence of Zero Vectors to the inverter, the sequence alternating between a first Zero Vector whereby motor current does not flow in the DC Bus and a second Zero Vector wherein the high and low side switches of the inverter are alternately turned on with active vector components being injected by the inverter for each inverter stage thereby to allow motor current to flow in the DC Bus, whereby the terminals of the motor during the first and second Zero Vectors are shorted to brake the motor without substantially raising the voltage of the DC Bus during the braking time; and the speed of the motor can be determined by measuring the current in a sensor of the DC bus during the time when the second Zero Vector is applied without using a sensor in the motor. | 10-30-2008 |
| 20090009117 | Brushless Motor Control Apparatus and Control Method and Motor System - A brushless motor control apparatus includes a mask processing unit to which digital induced voltage signal is input, a energizing current timing generation processing unit, a pulse width detection unit, and an advance angle correction unit for performing advance angle correction. The pulse width detection unit measures pulse width of spike voltage, and the advance angle correction unit calculates the correction to the advance angle according to the length of this pulse width. The energizing current timing generation processing unit takes half the value obtained after subtracting the correction value from the edge interval of the position detection signal generated in the mask processing unit as the advance angle. | 01-08-2009 |
| 20090026991 | SYNCHRONIZATION OF SEQUENTIAL PHASE SWITCHINGS IN DRIVING STATOR WINDINGS OF A MULTIPHASE SENSORLESS BRUSHLESS MOTOR AT SUB BEMF-DETECTABILITY SPEEDS - The method of synchronizing sequential phase switchings in driving stator windings of a multiphase sensorless brushless motor with a reconstructed information on the current angular position of a permanent magnet rotor, includes sampling on a currently non-conductive stator winding a voltage induced thereon by the resultant magnetic field produced by the drive current forced through currently conductive stator windings that inverts its sign when the rotor transitions across a plurality of significant angular positions, at which orthogonality between the resultant magnetic field and a magnetic axis of the non-excited winding verifies. The sign of the sampled voltage induced on the currently non-excited winding is compared with the sign that is expected upon transiting across the angular position of inversion by the moving rotor for the current phase drive configuration to sequentially switch to the next phase drive configuration upon verifying conformity of the sign of the sampled voltage with the expected sign. | 01-29-2009 |
| 20090033263 | METHOD AND RELATED CIRCUIT FOR DRIVING A SENSORLESS BRUSHLESS MOTOR - A method of driving a sensorless brushless motor in PWM mode includes tristating a winding during a time window for detecting a zero-cross of the back electromotive force induced in the winding by rotation of a rotor, monitoring voltage of the tristated winding during an unmasked portion of the time window, and detecting during the time window a zero-cross event of the induced back electromotive force. The method includes verifying whether the zero-cross event occurred during the unmasked portion, modifying for the next cycle the duration of the time window and/or of the unmasked portion thereof based upon the verification, defining a safety interval in the unmasked time window, modifying the duration of the time window and/or of the unmasked portion thereof depending on whether the zero-cross event has been detected during the safety interval. | 02-05-2009 |
| 20090066278 | STEPPING MOTOR DRIVE AND STEPPING MOTOR DRIVING METHOD - In a drive of a stepping motor, an electromotive force is generated on the coil of a motor with a sinusoidal wave having the same period as an energization period by smoothly rotating a rotor with microstep driving, and an induced power is stably detected by detecting the electromotive force at the zero cross of driving current. The detection around the current zero cross makes it possible to shorten a detection section, form a driving waveform with few distortions, and perform driving with a driving waveform as in an ordinary micro step. Thus a circuit is provided which is aimed at reducing noise, vibrations, and loss of synchronization, and increasing current consumption efficiency in the determination of stop. | 03-12-2009 |
| 20090096397 | RELATING TO DRIVING BRUSHLESS DC (BLDC) MOTORS - In a three phase BLDC motor the rotor position is monitored by detecting the zero crossing points of the induced back EMF signals BEMF_U, BEMF_V, BEMF_W in the phase windings U, V, W. As they are illustrated, the back EMF signals are substantially sinusoidal but they may in other situations be substantially trapezoidal. The three back EMF signals are 120° out of phase with each other. In order to accurately monitor the back EMF in a phase winding, the driving waveform for each phase U, V, W includes an undriven period P close to the expected zero crossing point. The period P can be a preset part of the driving waveform or can be an interruption of the normal driving waveform in response to suitable interrupt signals. In order to determine the zero crossing points of each back EMF signal, two (or more) samples of the back EMF are taken during the undriven period P and used to interpolate the back EMF signal to determine the zero crossing point. | 04-16-2009 |
| 20090153086 | MOTOR DRIVE APPARATUS - The present invention provides a motor drive apparatus which improves a trade-off relation between a stable position detection and noise at its driving. A sensorless drive operation circuit calculates by operation a zero cross point (point p) of a voltage of a position detection phase at the next interval, using time information measured based on an output signal from a comparison circuit at the previous interval and the present interval. After the point p has been calculated, points a and b are detected by interrupting a predetermined time drive current. | 06-18-2009 |
| 20090218974 | DRIVING BRUSHLESS DC (BLDC) MOTORS - The driving system for a tri-polar electric motor ( | 09-03-2009 |
| 20090289588 | APPARATUS AND METHOD FOR DRIVING A MOTOR - A sampling circuit samples, while running a motor at a predetermined rotational speed, over a predetermined period a back electro-motive force induced at one end of at least one phase coil, with one end of each phase coil of the motor being brought to a high impedance. A waveform data generating circuit holds as waveform data SIN the back electro-motive force beforehand sampled by the sampling circuit. A PWM signal generating circuit sequentially reads the waveform data SIN from the waveform data generating circuit to generate a PWM signal Spwm, the pulse width of which is modulated. | 11-26-2009 |
| 20100019710 | Method and device for determining the position of a rotor of a brushless and sensorless electric motor - The invention relates to a method carried out with simple means for determining the position of the rotor in a sensorless and brushless multi-phase electric motor ( | 01-28-2010 |
| 20100039056 | ELECTRIC POWER CONVERTER - A voltage-command correction unit provided between an electric-power conversion unit and a voltage-command calculation unit provides a predetermined current range including the zero level for the detected output current, and, at a first clock time when the output current enters from outside to inside of the current range, sets a zero cross timing of the output current as a clock time for switching the polarity of the correction voltage that corrects the AC voltage command calculated and output by the voltage-command calculation unit based on the first clock time and the frequency, thereby making a configuration capable of correcting the AC voltage command with the correction voltage with the same polarity as the polarity of the output current around the zero cross point of the output current. | 02-18-2010 |
| 20100102766 | Brushless, Three Phase Motor Drive - A control method for a sensor-less, brushless, three-phase DC motor. A pulse-width modulation (PWM) duty cycle may be calculated. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error. The delta zero crossing error may be multiplied by a first constant representing electromechanical properties of the motor to produce a representation of an angular velocity. One or more time values may be generated based on the representation of the angular velocity. Operation of the motor may be controlled based on the one or more time values and the PWM duty cycle. | 04-29-2010 |
| 20100181953 | Controller and MCU chip for controlling 3-phase brushless DC motor - The present invention discloses a 3-phase brushless DC motor controller, which comprises: a unit for generating a PWM signal; an ADC for converting a back electromotive force (BEMF) signal from an analog form into a digital form; a synchronization and extraction unit operating in synchronization in part with the PWM signal for extracting the digital BEMF signal to obtain a corresponding ZCP signal; and a unit for judging whether a commutation operation is to be performed according to a change of the corresponding ZCP signal. Await instruction and a delay instruction help to accurately acquire the digital BEMF signal. | 07-22-2010 |
| 20100201298 | ELECTRIC DRIVE AND METHOD FOR CONTROLLING IT - An electric drive ( | 08-12-2010 |
| 20100207562 | METHOD AND APPARATUS FOR DRIVING A BRUSHLESS D.C. MOTOR - A brushless D.C. motor includes having a rotor and a plurality of stator windings that define a stator field when driven by a bridge circuit, where a microprocessor drives the bridge circuit using a pulse-width modulation logic. The brushless D.C. motor is driven by triggering a commutation of the stator field; voltage induced by rotating the rotor in a non-energized stator winding is monitored to determine whether the voltage reaches, exceeds or is below a threshold voltage. A delay time between triggering the commutation of the stator field and the voltage reaching, exceeding or being below the threshold voltage is determined; and using the determined delay time a triggering time point for a next commutation of the stator field. | 08-19-2010 |
| 20100295490 | MOTOR DRIVE APPARATUS AND MOTOR DRIVE METHOD - A zero-crossing detector compares a neutral node voltage of a motor with a back electromotive force of at least one of windings and outputs a first signal every time a zero-crossing is detected as a result of the comparison. A cycle detector detects a cycle of the first signal and outputs a second signal during a final portion of the cycle. A de-energizer de-energizes all the windings of the motor during at least a period of time that the second signal is being output. The zero-crossing detector performs detection of a zero-crossing during the period of time that the second signal is being output. | 11-25-2010 |
| 20100301791 | BRIDGE RECTIFIER CIRCUIT - A bridge rectifier circuit, which takes control of a current flowing through an armature winding of a motor-generator and a battery, includes rectifier elements each made of a MOSFET; phase current detection means that detect the amount and the direction of current flowing between the drain and the source of the FET; and a control means that takes on/off control of the FET by applying a control voltage between the gate and the source thereof; wherein when the phase current detection means detect a reverse current flowing through the FET exceeding a first predetermined value, the control means applies a control voltage between the gate and the source of the FET so as to turn on the FET. | 12-02-2010 |
| 20110062910 | Method of Driving DC Motor and Related Circuit for Avoiding Reverse Current - A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result. | 03-17-2011 |
| 20110074327 | CONTROL OF SINUSOIDALLY DRIVEN BRUSHLESS DC (BLDC) MOTORS - In response to the determination or estimation of a back EMF zero crossing event for the phase, a time T | 03-31-2011 |
| 20110084639 | SYNCHRONIZED MINIMUM FREQUENCY PULSE WIDTH MODULATION DRIVE FOR SENSORLESS BRUSHLESS DIRECT CURRENT MOTOR - Drive voltages to a sensorless brushless DC motor are regulated by varying the width of a single drive pulse (PWM pulse) centered in each of the commutation periods. Switching losses are thereby cut to an absolute minimum because there are only two transitions (on and off) in each drive commutation period. Back EMF zero-cross detectors determine the electrical timing relationships during each electrical cycle. Since the PWM drive pulses are always centered in each of the commutation periods, there will always be back EMF available for measurement of “zero-crossings.” A digital device controls power switching transistors to produce one single PWM pulse during each of the commutation periods. | 04-14-2011 |
| 20110084640 | VARIABLE PULSE WIDTH MODULATION FOR REDUCED ZERO-CROSSING GRANULARITY IN SENSORLESS BRUSHLESS DIRECT CURRENT MOTORS - Zero-crossing detection accuracy is enhanced in a sensorless brushless direct current (BLDC) motor by increasing the PWM drive frequency in anticipation of a zero-crossing event in any one or more commutation periods. Once a zero-crossing event is detected, the PWM frequency can go back to a lower normal operating frequency. Switching losses of the power drive transistors are thereby minimized while maintaining accurate zero-crossing detection for stable operation of the BLDC motor. | 04-14-2011 |
| 20110115423 | Brushless, Three Phase Motor Drive - A control method for a brushless, three-phase DC motor. A voltage induced by rotation of a rotor may be sampled at a first expected zero crossing value to produce a first sampled voltage value. An average of a plurality of sampled voltage values, including voltage values sampled at a plurality of prior expected zero crossing values and the first sampled voltage value, may be calculated. The first sampled voltage value may be subtracted from the calculated average to produce a delta zero crossing error. A pulse-width modulation duty cycle may be adjusted based on the delta zero crossing error. The pulse-width modulation duty cycle may be used to control a rotational velocity of the rotor. | 05-19-2011 |
| 20110127939 | PAIR POLE ASYMMETRY COMPENSATION IN BACK ELECTROMOTIVE FORCE ZERO CROSS DETECTION - Disk drive spindle jitter is comprised of electrical noise, error due to pair pole asymmetry, and random disk speed variances. Error caused by pair pole asymmetry can be identified and compensated for by detecting over a single rotation of a rotor a plurality of zero cross signals. These signals can be statistically analyzed over a period of a plurality of revolutions of the rotor so as to identify the systematic error caused by pair poles. Once identified, this pair pole error can be used to modify zero cross signals and/or modify commutation signal driving the disk so as to arrive at a more accurate determination of disk speed and to precisely control the speed of the disk. | 06-02-2011 |
| 20110210688 | CONTROL OF BRUSHLESS MOTOR - Systems and methods for generating a signal useful in the commutation of current through windings of brushless direct current electric motors are provided. Such methods comprises detecting a kickback pulse in a non-driven winding of a motor; detecting a rotor-induced zero crossing in the non-driven winding following the detection of the kickback pulse; and using the detection of the rotor-induced zero crossing to generate a signal useful in commutation of the motor. | 09-01-2011 |
| 20110221371 | ACCURACY OF ROTOR POSITION DETECTION RELATING TO THE CONTROL OF BRUSHLESS DC MOTORS - During operation of a 3 phase BLDC motor it is driven by use of a PWM waveform applied to one of the driven phase (curve a). The other driven phase is connected thereto but no driving signal is applied (curve b). The third phase is left floating (curve c). This allows the back EMF in the third phase to be monitored for the purpose of determining rotor position by detection of zero crossing points. The rapid switching of the PWM pulses causes ringing in the back EMF signal indicated for one pulse by the ringed portions | 09-15-2011 |
| 20110241588 | SYSTEM AND METHOD FOR CONTROLLING SENSORLESS MOTOR - A system and a method for controlling a sensorless motor are disclosed, where the system includes a motor driver and a zero crossing detector. The motor driver can drive the sensorless motor. The zero crossing detector can detect a zero-crossing point when the voltage of one motor coil of the sensorless motor is in a blanking period. | 10-06-2011 |
| 20110260665 | POSITIONAL RECOGNITION USING BEMF ZERO CROSSOVER RECOGNITION OF A ROTOR OF AN ELECTRONICALLY COMMUTATED ELECTRIC MACHINE WITH TWO COIL SECTIONS OF DIFFERENT INDUCTANCES - The invention relates to a method for positional recognition of a rotor of an electronically commutated electric machine, in particular an electric motor, in which a zero crossover of a voltage induced in a coil section of the rotor or stator is used for positional recognition. According to the invention, to determine the zero crossover the coil section is briefly powered down. A rotor/stator is used, comprising at least two coil sections, one of which has a lower inductance relative to the other one, and preferably only the coil section with the lower inductance is used for the positional recognition. | 10-27-2011 |
| 20110316464 | ELECTRIC DEVICE COMPRISING AN ALTERNATING CURRENT ELECTRIC MOTOR AND A CONTROL INVERTER AND A METHOD FOR MEASURING THE ELECTROMOTIVE FORCE OF THIS DEVICE - The invention relates to an electric device ( | 12-29-2011 |
| 20120068649 | BACK-EMF DETECTION FOR MOTOR CONTROL - Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval. | 03-22-2012 |
| 20120086376 | ELECTRIC MOTOR OPERATION APPARATUS AND METHOD - The invention relates to a method for operating an electric motor with a primary section and a secondary section, wherein the primary section has a multi-phase exciter winding comprising winding strands, each of the phase connections of said exciter winding being connected to an output connection of an end stage, wherein the end stage has controllable semi-conductor switches for applying phase voltages to the output connections, said method comprising the following steps: a) introducing an operating phase by applying the phase voltages to the output connections of the end stage such that a moving magnetic field is induced in the exciter winding, said moving field effecting a relative motion between the primary section and the secondary section, b) hinting off the phase voltage at at least one of the output connections in order to introduce a measurement phase, c) measuring the electrical back emf induced in the winding strand connected to said at least one of the output connections by virtue of the relative motion between the primary section and the secondary section in order to determine the angular difference between the phase position of the exciter current and that of the back emf, d) optionally, repeating steps a) through c). After turning off the phase voltage, the winding current in the winding strand for which the phase voltage was turned off is conducted and maintained by way of at least one free-wheeling element having a non-linear characteristic curve. A flank ( | 04-12-2012 |
| 20120112675 | Sensorless Safety System for Determining Rotation of an Electric Household Appliance Laundry Drum Powered by a Three-Phase Asynchronous Motor - An electric household appliance ( | 05-10-2012 |
| 20120249034 | POSITION SENSING CIRCUIT FOR BRUSHLESS MOTORS - A position sensing circuit ( | 10-04-2012 |
| 20120256575 | CONTROL METHOD FOR SENSORLESS MOTORS WITH ENERGY RECOVERY ABILITY - The present disclosure related to a control method for a sensorless motor with energy recovery ability, using which duty cycle of a sensorless motor can be changed by the control of complementary switches so as to enable the sensorless motor to switch between a high efficiency driving operation and an energy recovery operation while being activated. Thereby, the conduction loss and the wear and tear to the switches can be minimized while simultaneously enhancing the energy recovery efficiency and thus improving the battery life. | 10-11-2012 |
| 20120326647 | ZERO-CROSSING DETECTION CIRCUIT AND COMMUTATION DEVICE USING THE ZERO-CROSSING DETECTION CIRCUIT - A zero-crossing detection circuit and a commutation device using the zero-crossing detection circuit are provided. The zero-crossing detection circuit is adapted into a three-phase brushless DC (direct current) motor with first to third coils. One terminal of each of the first to third coils is electrically coupled together with each other. The detection circuit comprises a first selection circuit, a second selection circuit and a comparator. The first selection circuit and the second selection circuit are both electrically coupled to another terminals of the first to third coils, to obtain first to third terminal voltages, and output one of the first to third terminal voltages according to a selection signal. The comparator is configured for comparing an output of the first selection circuit and an output of the second selection circuit, to output a comparing result. | 12-27-2012 |
| 20130009582 | SINGLE-PHASE BRUSHLESS MOTOR DRIVE CIRCUIT - A driving circuit for a single-phase-brushless motor, includes: a driving-signal-generating circuit to generate a driving signal for supplying, to a driving coil of the single-phase-brushless motor, first- and second-driving currents, alternately with a de-energized period therebetween during which neither of the first or the second driving current is supplied to the driving coil; an output circuit to supply the first or the second driving current to the driving coil in response to the driving signal; and a zero-cross detecting circuit to detect a zero cross of an induced voltage, generated across the driving coil, during the de-energized period, wherein the driving-signal-generating circuit determines a length of a subsequent energized period based on a driving cycle from a start of an energized period, during which the output circuit supplies the first or the second driving current to the driving coil, to a time when the zero-cross-detecting circuit detects the zero cross. | 01-10-2013 |
| 20130020974 | SINGLE-PHASE BRUSHLESS MOTOR DRIVE CIRCUIT - A driving circuit for a single-phase brushless motor includes: a driving-signal-generating circuit to generate a driving signal for supplying first and second driving currents to a driving coil of the single-phase brushless motor in an alternate manner with a de-energized period therebetween; an output circuit to supply the first or the second driving current to the driving coil in response to the driving signal; and a zero-cross detecting circuit to detect a zero cross of an induced voltage, generated across the driving coil, during the de-energized period, wherein the driving-signal-generating circuit determines a length of a subsequent energized period, based on a driving cycle from a start of an energized period to a time when the zero-cross detecting circuit detects the zero cross, and the zero-cross-detecting circuit starts detection of the zero-cross after a predetermined time period has elapsed from a start of the de-energized period. | 01-24-2013 |
| 20130033212 | SENSORLESS BLDC MOTOR CONTROL BY COMPARING INSTANTANEOUS & AVERAGE BEMF VOLTAGES - Sensorless driving of a brushless DC (BLDC) motor includes detecting a zero crossing time from back electromotive force (BEMF) voltage of the BLDC motor. An instantaneous BEMF voltage and an average BEMF voltage are compared to detect the crossover time, which can be used to change the commutation switching sequence. Since the average BEMF voltage differs for odd and even steps of the commutation switching sequence, average BEMF voltages are calculated separately for odd and even sequences and compared to instantaneous BEMF voltages to detect crossover points for the odd and even sequences. The times to commutations for the odd and even sequences are averaged to provide an average time to the next commutation cycle. The average time can be scaled by a reduction factor to reduce the effects of measurement noise. | 02-07-2013 |
| 20130038260 | METHOD AND APPARATUS FOR DYNAMICALLY ADJUSTING A DEAD TIME OF BRUSHLESS DIRECT CURRENT MOTOR DURING A PHASE CHANGE - A method and apparatus for dynamically adjusting a dead time of a BLDC motor during a phase change detect the winding current of the BLDC motor during the dead time, and terminate the dead time when the winding current is detected to be substantially or close to zero. Thus, the method and apparatus can optimize the dead time and switch the BLDC motor between two phases at a zero-current point, without reducing the maximum rotation speed of the BLDC motor. | 02-14-2013 |
| 20130038261 | Sensor-Less Driving Method of Permanent Magnet AC Motor - A permanent-magnet AC motor comprises a motor and a controller coupled to the motor. The motor includes a winding. The controller includes a drive model configured to provide a drive current. Waveform of the drive current is spatially symmetrical. The winding has a waiting zone having electrical angle of 30° and a driving zone having electrical angle of 150° in each half electrical cycle when the motor is in operation. The driving zone is equally divided into five driving sub-zones. | 02-14-2013 |
| 20130127385 | Sample and Hold Time Stamp for Sensing Zero Crossing of Back Electromotive Force in 3-Phase Brushless DC Motors - A microcontroller determines the position of the rotor of a brushless, direct-current motor by determining the time of zero crossing of back electromotive force (EMF) emanating from the non-driven phase winding. The zero crossing point is determined by interpolating voltage differentials that are time stamped. Each voltage differential is the difference between the phase voltage of the phase winding and the motor neutral point voltage. The time of zero crossing is determined without using a comparator and without interrupting the processor at each zero crossing point. The processor interpolates the time of zero crossing independently of when the zero crossing point occurs. A hold signal conductor is connected both to a sample and hold circuit and to the load input lead of a time stamp register. The microcontroller simultaneously captures a phase voltage in the sample and hold circuit and a timer count in the time stamp register. | 05-23-2013 |
| 20130181647 | METHOD AND APPARATUS FOR DRIVING A POLYPHASE ELECTRONICALLY COMMUTATED ELECTRIC MACHINE AND A MOTOR SYSTEM - The invention relates to a method for operating an electronically commutated electric machine ( | 07-18-2013 |
| 20130234640 | SENSORLESS CONTROL OF A BRUSHLESS PERMANENT-MAGNET MOTOR - A method of controlling a brushless permanent-magnet motor. The method includes generating a first signal having a voltage that is proportional to a voltage across a winding of the motor, and generating a second signal having a voltage that is proportional to a current in the winding. The second signal is then differentiated to generate a third signal, and the voltages of the first signal and the third signal are compared. An output signal is generated in response to the comparison, the output signal having an edge whenever the voltages of the first signal and the third signal correspond. The winding is then commutated at times relative to the edges in the output signal. Additionally, a control system that implements the method, and a motor system that incorporates the control system. | 09-12-2013 |
| 20130249459 | FILTER APPARATUS AND METHOD FOR BRUSHLESS DC MOTORS - In a multi-phase brushless DC motor, a zero crossing N-bit filter includes a comparator and a phase multiplexer. The phase multiplexer connects each motor phase to each of a positive and a negative input of the comparator, with a switch in each connection to form a switch array. A microprocessor is disposed to operate the switches, and is configured to measure a BEMF for a first phase by opening the switches connecting all other phases to the positive input of the comparator and by opening the switch connecting the first phase being measured to the negative input of said comparator. The comparators output is received by a shift register. The microprocessor is configured to respond to a zero crossing when a majority of bits in the shift register change between high and low. | 09-26-2013 |
| 20130285586 | INVERTER CONTROL DEVICE, ELECTRIC COMPRESSOR, AND ELECTRIC DEVICE - An inverter control device of the present invention operates by synchronous commutation in which a commutation signal waveform is output with an electric angle of less than 180 degrees at a predetermined frequency according to a target rotation speed of a brushless DC motor. In order to maintain an induced voltage phase of a brushless DC motor at a predetermined phase with respect to an output voltage of an inverter circuit unit, even in an operation by the synchronous commutation, the output voltage of the inverter circuit unit is changed according to a change in state of the induced voltage phase of the brushless DC motor to continue a running state of the motor. Therefore, a more stable motor operation can be performed during synchronous running by the forced commutation. | 10-31-2013 |
| 20140035501 | BRUSHLESS MOTOR CONTROL DEVICE AND BRUSHLESS MOTOR CONTROL METHOD - Regarding a brushless motor control device and a control method, the phase voltage Vsu of any one phase of the three-phase brushless motor is detected by a sub-coil (Su) ( | 02-06-2014 |
| 20140042945 | METHOD FOR THE SENSORLESS COMMUNICATION DETECTION OF ELECTRONICALLY COMMUTATED ELECTRIC MOTORS - The invention relates to a method for the sensorless commutation detection of electronically commutated electric motors, in which the phase current is interrupted for a blanking time in order to detect the zero passage. On the basis of the profile of the mutual induction voltage, a decay time, which is characteristic for a decay of the phase current, is determined within the blanking time and the start of the blanking time is determined as a function of the time difference between the decay time and the end of the blanking time. | 02-13-2014 |
| 20140062365 | Electronic Circuit and Method for Detecting a Zero Current in a Winding of an Electric Motor - A motor control circuit and associated techniques detect a zero crossing of a current in a motor winding by detecting a revers current in a half bridge circuit used to drive the motor winding. | 03-06-2014 |
| 20140111131 | METHOD AND APPARATUS FOR WINDOWLESS BEMF DETECTION - A zero crossing of a motor current waveform at the terminal of a brushless sensor-less multi-phase DC motor is determined without opening a non-drive period while the motor is continuously driven. A voltage level at a first threshold at the terminal of a motor is detected. At a first time, a current flow switch connected to the terminal is switched. At a second time, a voltage level at a second threshold is detected at the terminal of the motor. The zero crossing is determined between the first time and the second time and used to synchronize the driving of the motor. | 04-24-2014 |
| 20140145662 | MOTOR DRIVING APPARATUS AND METHOD - 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. | 05-29-2014 |
| 20140152220 | MOTOR DRIVING CONTROL APPARATUS AND METHOD, AND MOTOR USING THE SAME - There are provided a motor driving control apparatus and method and a motor using the same. The motor driving control apparatus includes: a back-electromotive force detecting unit detecting back-electromotive force of a motor apparatus; a gradient calculating unit calculating a gradient of a waveform of the detected back-electromotive force; and a controlling unit calculating a zero-crossing point of the back-electromotive force using the calculated gradient and controlling driving of the motor apparatus using the calculated zero-crossing point. | 06-05-2014 |
| 20140152221 | MOTOR DRIVING CONTROL APPARATUS AND METHOD, AND MOTOR USING THE SAME - There are provided a motor driving control apparatus and method, and a motor using the same. The motor driving control apparatus includes: a back-electromotive force detecting unit detecting back-electromotive force generated in a motor apparatus; a zero-crossing calculating unit sampling the back-electromotive force and determining a zero-crossing point using an average value of adjacent sections in the sampled back-electromotive force; and a controlling unit controlling driving of the motor apparatus using the zero-crossing point. | 06-05-2014 |
| 20140152222 | ELECTRONIC COMMUTATION METHOD IN DIRECT CURRENT ELECTRIC MOTORS - In an electronic commutation method in direct current electric motors which are controlled by pulse width modulation of the energization which takes place periodically with positive and negative current values and intermediate energization pauses, the counter-induction voltage is measured, wherein the zero crossing of the counter-induction voltage is determined by means of the point of intersection of the envelope to the counter-induction voltage with the zero line. The pulse width modulation of the energization is changed if the zero crossing is covered by positive or negative current values of the energization. | 06-05-2014 |
| 20140167667 | MOTOR DRIVING APPARATUS AND METHOD - There are provided a motor driving apparatus and method, the motor driving apparatus including a current detecting unit detecting a level of a driving current applied to a motor for each predetermined period, a current comparing unit comparing the level of the driving current detected by the current detecting unit in a previous period and the level of the driving current detected by the current detecting unit in a current period, and a controlling unit adjusting a level of a reference signal compared with a back electro motive force (BEMF) signal of the motor based on an output of the current comparing unit. | 06-19-2014 |
| 20140167668 | MOTOR DRIVING CONTROL APPARATUS, MOTOR DRIVING CONTROL METHOD, AND MOTOR USING THE SAME - There are provided a motor driving control apparatus, a motor driving control method, and a motor using the same. The motor driving control apparatus includes a driving signal generation unit, a back electromotive force detection unit, and a frequency controller. The driving signal generation unit may generate a driving control signal for controlling driving of a motor device. The back electromotive force detection unit may detect back electromotive force of the motor device. The frequency controller may provide control to estimate a zero crossing point of the back electromotive force, set a frequency modulation section including the zero crossing point, and modulate a frequency of the driving control signal during the frequency modulation section. | 06-19-2014 |
| 20140176032 | BACK ELECTROMOTIVE FORCE DETECTION CIRCUIT, AND MOTOR DRIVING CONTROL APPARATUS AND MOTOR USING THE SAME - There are provided a back electromotive force detection circuit, and a motor driving control apparatus and a motor using the same. The back electromotive force detection circuit includes: a voltage generating unit generating a voltage in inverse proportion to a duty ratio of a pulse width modulation (PWM) signal; a variable amplifier controlling a gain according to the voltage generated by the voltage generating unit, and amplifying back electromotive force according to the controlled gain; and a comparator comparing an output from the variable amplifier with a pre-set reference signal, and outputting a zero-crossing signal of the back electromotive force. | 06-26-2014 |
| 20140239864 | VARIABLE LINK SENSORLESS BRUSHLESS DIRECT CURRENT MOTOR CONTROLLER FOR SPACE AND HARDENED APPLICATIONS - 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. | 08-28-2014 |
| 20150069942 | Tri-Stating Brushless DC Motor Phase for Direct Detection of Back EMF Zero Cross - A back electromotive force (BEMF) zero cross may be detected in a brushless direct current (BLDC) motor that is controlled by pulse width modulation (PWM). A phase input of the BLDC motor is tri-stated during PWM periods in which the phase input conducts motor drive current, and the tri-stating of the phase input is used to determine whether a BEMF zero cross has occurred in the BLDC motor. | 03-12-2015 |
| 20150069943 | MOTOR DRIVING CONTROL APPARATUS, MOTOR DRIVING CONTROL METHOD, AND MOTOR SYSTEM USING THE SAME - There are provided a motor driving control apparatus, a motor driving control method and a motor system using the same. The motor driving control apparatus includes: a back-electromotive-force detecting unit detecting back electromotive force generated by a motor apparatus; a floating correcting unit, if zero-crossing has not occurred in a current floating area, correcting the floating area by predicting a time at which a zero-crossing occurs; and a control unit determining a zero-crossing time of the back electromotive force based on an output from the floating correcting unit and controlling driving of the motor apparatus using the determined zero-crossing time. | 03-12-2015 |
| 20150069944 | MOTOR DRIVING CONTROL APPARATUS, MOTOR DRIVING CONTROL METHOD AND MOTOR SYSTEM USING THE SAME - There are provided a motor driving control apparatus, a motor driving control method, and a motor system. The motor driving control apparatus includes: a zero-crossing detecting unit detecting back electromotive force generated in a motor apparatus and detecting a zero-crossing point of the back electromotive force; a commutation point calculating unit calculating an average value for zero-crossing points detected at least three times to determine a commutation point using the calculated average value; and a control unit controlling a phase change of the motor apparatus using the commutation point. | 03-12-2015 |
| 20150123582 | MOTOR DRIVING APPARATUS AND CONTROLLING METHOD THEREOF - Disclosed herein is a motor driving apparatus, including: an inverter applying a direct current voltage to the respective phases of a brushless DC (BLDC) motor by a switching operation; and a motor driver detecting counter electromotive force patterns in floating sections of the respective phases, detecting zero cross points (ZCPs) of the respective phases using the counter electromotive force patterns, and then generating a PWM signal for controlling a switching operation of the inverter and a phase switching of the respective phases using position information of the zero cross points (ZCPs). | 05-07-2015 |
| 20150123583 | MOTOR DRIVING CONTROL APPARATUS AND METHOD, AND MOTOR SYSTEM USING THE SAME - A motor driving control apparatus may include a zero cross point (ZCP) detecting unit detecting back electromotive force generated by a motor apparatus and detecting a plurality of zero cross points in the back electromotive force, a zero cross point correcting unit correcting the plurality of zero cross points when a time interval between the plurality of zero cross points is equal to a predetermined error period or longer, and a controlling unit controlling driving of the motor apparatus using the plurality of corrected zero cross points. | 05-07-2015 |
| 20150145455 | Phase Current Regulation in BLDC Motors - A method is provided for determining a phase current direction and a zero-crossing moment of the phase current in a sinusoidally controlled brushless direct current motor. The brushless direct current motor comprises a coil per phase and the phase of the brushless direct current motor is driven by a half bridge driver. The half bridge driver comprises a high side field effect transistor and a low side field effect transistor. The method comprising the following steps: measuring the drain source voltage over the high side field effect transistor and low side field effect transistor, and determining the zero crossing moment of the phase current by determining the current direction based on the measured drain source voltages and by determining the moment the current changes direction. | 05-28-2015 |
| 20160099668 | Motor Control Circuit System - A motor control circuit system is arranged to control the activation of a motor when a rotating voltage of the motor equals to a predetermined threshold so as to save the power consumption of the motor, wherein no current is allowed to pass to the motor before the rotating voltage of the motor reaches again the predetermined threshold. Therefore, the motor is electrified in an interval manner, such that the driven mechanism runs with its inertia even though the motor is idle, i.e. no current passing to the motor, so as to save the energy output of the motor. | 04-07-2016 |
| 20160181956 | ZERO CROSSING DETECTION CIRCUIT FOR MOTOR CONTROLLER AND METHOD THEREFOR | 06-23-2016 |
| 20160254766 | BLDC ADAPTIVE ZERO CROSSING DETECTION | 09-01-2016 |
