Including Motor Current Or Voltage Sensor Patents (Class 324/177)
  • Patent number: 9787232
    Abstract: Provided are an apparatus and method for controlling a ripple current sensing motor. An apparatus for controlling a ripple current sensing motor may include a first shunt resistor having one end connected to one end of a motor and the other end of the first shunt resistor connected to a ground, a second shunt resistor having one end connected to the other end of the motor and the other end of the second shunt resistor connected to the ground, a first amplifying circuit amplifying a first signal from one end of the motor, a second amplifying circuit amplifying a second signal from the other end of the motor, and a detector detecting a rotation amount and a rotation direction of the motor using a change in voltages of a first detection signal from the first amplifying circuit and a second detection signal from the second amplifying circuit.
    Type: Grant
    Filed: September 12, 2016
    Date of Patent: October 10, 2017
    Assignees: Hyundai Motor Company, Omron Automotive Electronic Korea Co., Ltd.
    Inventors: Jeong Gi Yun, Dong June Song, Hun Joung Yoon, Hee Sung Jang, In Cheol Ryu
  • Patent number: 9000710
    Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including a first filter for receiving a substantially DC component of the motor current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the motor current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the current fluctuation corresponding to motor speed of the brush DC motor. The adaptive bandpass filter uses debounce filtering to reduce rapid filter passband switching, and a run-in period prior to passband switching to obviate transient effects of filter switching.
    Type: Grant
    Filed: June 11, 2012
    Date of Patent: April 7, 2015
    Assignee: Lexmark International, Inc.
    Inventor: Stefan Mark Atay
  • Patent number: 8907656
    Abstract: An integrated current sensing apparatus includes a magnetic-field sensing element, a power supply circuit, an offset adjustment circuit, a gain adjustment circuit and a regulating unit. The magnetic-field sensing element is configured for sensing magnetic field, and correspondingly generating a sensing voltage. The power supply circuit is electrically coupled to the magnetic-field sensing element, for generating a constant current to the magnetic-field sensing element to control the sensing voltage. The offset adjustment circuit is electrically coupled to the magnetic-field sensing element, for adjusting an offset of the sensing voltage. The gain adjustment circuit is electrically coupled to the offset adjustment circuit, for amplifying the sensing voltage to a rated output voltage. The regulating unit is electrically coupled to the power supply circuit, the offset adjustment circuit and the gain adjustment circuit, for controlling the constant current, the offset and a gain value.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: December 9, 2014
    Assignee: Delta Electronics, Inc.
    Inventor: Shih-Tsung Chen
  • Patent number: 8841900
    Abstract: A combined measurement device for measuring current and/or voltage of an electrical conductor, comprising a supporting body, a current sensor housed inside the supporting body, and a voltage sensor located at least partially inside the supporting body. A shielding is positioned around the current sensor. The current sensor and the voltage sensor are mutually arranged so as the shielding shields at least partially both the current sensor and the voltage sensor against external electric field disturbances.
    Type: Grant
    Filed: June 12, 2009
    Date of Patent: September 23, 2014
    Assignee: ABB Technology AG
    Inventors: Radek Javora, Petr J. Kral
  • Patent number: 8659250
    Abstract: A management apparatus is described of a rotating motor and a load during power loss; the apparatus comprises a first switching circuit coupled with the rotating motor and a controller of said first switching circuit. The controller is configured to drive the first switching circuit so as to convert a back-electromotive force voltage developed in the rotating motor into a power supply voltage for the load. The first switching circuit is driven in accordance with a first duty cycle. The apparatus comprises a second switching circuit coupled with the load and driven in accordance with a second duty cycle. The controller is configured to vary said first and said second duty cycles to keep the power supply voltage for the load above or equal to a threshold voltage.
    Type: Grant
    Filed: December 19, 2011
    Date of Patent: February 25, 2014
    Assignee: STMicroelectronics S.r.l.
    Inventors: Giuseppe Maiocchi, Ezio Galbiati
  • Patent number: 8633727
    Abstract: A power generation system includes a support unit configured to support a power transmission line disposed on a transmission line tower, and a power generation unit. The support unit includes a support line having an end part connected to the power transmission line and a rotary body configured to rotate in a manner cooperating with the support line. The power generation unit is configured to generate electric power in response to rotation of the rotary body caused by movement of the support line resulting from tension of the power transmission line.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: January 21, 2014
    Assignee: Empire Technology Development LLC
    Inventor: Kenichi Fuse
  • Patent number: 8589101
    Abstract: An apparatus for measuring RMS values of burst-fired currents includes a current sensor having a signal output, an analog-to-digital (A/D) converter coupled to the signal output of the current sensor, a digital processor coupled to an output of the A/D converter, and a digital memory coupled to the digital processor. Code segments stored in the digital memory are executable on the digital processor and implement a process of: a) initially sampling the output of the A/D converter; b) determining from the initial sampling a burst-fired current pattern; c) sampling the output of the A/D converter N times within a burst-fired current pattern to provide N samples; and d) calculating an RMS value from the N samples.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: November 19, 2013
    Assignee: Neilsen-Kuljian, Inc.
    Inventors: Huy D. Nguyen, Tom Lik-Chung Lee
  • Patent number: 8531182
    Abstract: A control system for use in safety critical human/machine control interfaces is described, more particularly a joystick type control system and particularly a joystick type control system utilizing magnetic positional sensing. The control system provides a control input device having a movable magnet, a pole-piece frame arrangement positioned about the magnet, at least three magnetic flux sensors being positioned in said pole-piece frame arrangement and a monitoring arrangement for monitoring the output signal of each of said at least three sensors.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: September 10, 2013
    Assignee: Penny & Giles Controls Limited
    Inventor: Dev Kumar Banerjee
  • Patent number: 8471589
    Abstract: A method for detecting whether the stator in a vehicle alternator has a turn-to-turn short circuit. The method includes determining an output current or voltage signal of the alternator, where the output current or voltage signal includes a ripple current frequency as a result of an AC-to-DC conversion. The method determines the speed of the alternator and a current output of the alternator. The method then determines the ripple current frequency of the alternator from the alternator speed, and determines a winding frequency from the ripple current frequency. The method performs an FFT analysis on the voltage and current signal, determines an amplitude of the winding frequency and compares the amplitude of the winding frequency to a predetermined amplitude, where if the difference exceeds a predetermined threshold, a turn-to-turn short circuit is likely occurring.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: June 25, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Yilu Zhang, Siwei Cheng, Mutasim A. Salman
  • Patent number: 8466648
    Abstract: A motor control device for a stepping motor including at least two phase coils and a rotor is provided. The motor control device includes a control unit which applies a pulse voltage subjected to pulse width modulation, to each of the at least two phase coils, a back electromotive voltage measuring unit which provides a halt period to temporarily halt the application of the pulse voltage to one of the phase coils when a direction of the coil current flowing in the one phase coil is switched, and which measures a back electromotive voltage induced in the one phase coil during the halt period, an out-of-step detecting unit which detects an out-of-step of the stepping motor if the measured back electromotive voltage satisfies a predetermined criterion, and a voltage control unit which sets a voltage for all phase coils other than the one phase coil to a constant voltage during the halt period.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: June 18, 2013
    Assignee: Minebea Co., Ltd.
    Inventors: Kazuo Takada, Takayuki Matsui
  • Publication number: 20120326704
    Abstract: A system for determining motor speed of a brush DC motor, including a first filter for receiving a substantially low frequency portion of a sensed current of the motor and parameters corresponding thereto, for calculating a speed estimate of the motor; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the sensed current and substantially isolating a first periodic current fluctuation thereof. A detected frequency of the first periodic current fluctuation corresponds to the speed of the brush DC motor. The system may include a tracking frequency selection block for selecting a frequency component of the sensed current and providing same to the first filter, wherein the speed estimate is based in part upon the selected frequency component.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 27, 2012
    Inventor: Stefan Mark Atay
  • Publication number: 20120326705
    Abstract: A system for determining motor speed of a brush DC motor in an apparatus, including a first filter for receiving a substantially DC component of the motor current and parameters corresponding to the brush DC motor, for calculating a speed estimate thereof; an adaptive bandpass filter having a center frequency corresponding to the speed estimate of the first filter, for receiving the motor current and substantially isolating a periodic current fluctuation thereof; a block for determining a frequency of the periodic current fluctuation, the current fluctuation corresponding to motor speed of the brush DC motor. The adaptive bandpass filter uses debounce filtering to reduce rapid filter passband switching, and a run-in period prior to passband switching to obviate transient effects of filter switching.
    Type: Application
    Filed: June 11, 2012
    Publication date: December 27, 2012
    Inventor: Stefan Mark Atay
  • Patent number: 8339078
    Abstract: This invention relates to an apparatus and method for deriving speed and position information for an electric motor. Apparatus for and a method of controlling a motor 100 are also disclosed. The apparatus for providing information relating to the operation of an electrical motor 100 comprises a sampler 50, 51 for sampling the instantaneous motor current is and a processor 160 for determining the instantaneous rate of change of the motor current and providing information about the motion or position of said motor based on said instantaneous rate of change of the motor current. In this way speed and position information can be provided, at low speeds, and without using a speed sensor.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: December 25, 2012
    Assignee: The City University of Hong Kong
    Inventor: Shu Yuen Ron Hui
  • Publication number: 20120259570
    Abstract: A system and method for determining the speed of an alternator, for example, a vehicle alternator. The method includes measuring the current or voltage of a vehicle battery for a predetermined period of time, and then notch filtering the measured current or voltage signal to remove known harmonics. A limited data point Fast Fourier Transform (FFT) spectrum analysis operation is performed to identify the frequency peaks in the filtered signal, where the highest peak represents a ripple current on the DC alternator signal. The highest peak in the FFT signal is identified, and an interpolation process is performed between that peak and an adjacent peak in the data to identify the actual frequency of the ripple current. The ripple current is then converted to the speed of the alternator.
    Type: Application
    Filed: April 11, 2011
    Publication date: October 11, 2012
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Yilu Zhang, Siwei Cheng, Mutasim A. Salman
  • Patent number: 8169214
    Abstract: An angular position sensor and method that relies on a stationary circular array of Hall sensors and a rotatable circular array of magnets arranged about a common axis. A periodic and simultaneous reading of all of the Hall sensor outputs is used to determine angular velocity.
    Type: Grant
    Filed: June 6, 2008
    Date of Patent: May 1, 2012
    Assignee: Hydro-Aire, Inc.
    Inventor: Mark Zak
  • Patent number: 8143830
    Abstract: A blushless direct current (BLDG) motor apparatus includes: a stator which is provided with a plurality of windings corresponding to N phases and wound in parallel independently of each other; a rotor which has a plurality of poles corresponding to the plurality of windings and rotates with respect to the stator by excitation of the windings; a switching unit which is provided in the form of a full H-bridge with respect to each phase, comprises a pair of upper switching devices corresponding to a (+) side of the winding and a pair of lower switching devices corresponding to a (?) side of the winding, and performs a switching operation to supply or not to supply driving power to the winding; a first sensing device which senses the phase of the rotor with respect to the stator to determine whether to turn on or off the upper switching device; a second sensing device which is provided in the latter part than the first sensing device and senses the phase of the rotor with respect to the stator to determine whethe
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: March 27, 2012
    Assignee: Creation & Motor Industries, Ltd.
    Inventors: Byung Gil Ha, Ji Seok Park
  • Publication number: 20100259249
    Abstract: In a method and a device for determining the position of a closing part of a vehicle, that can be moved by a direct-current motor, a motor current signal is derived from the direct-current motor and converted into a digital signal by an analog-digital converter. The signal is filtered and forwarded to a position counter for counting the current ripple. The scanning frequency of the analog-digital converter is modified according to the rotational speed of the direct-current motor.
    Type: Application
    Filed: October 24, 2008
    Publication date: October 14, 2010
    Inventor: Roman Morawek
  • Publication number: 20100148760
    Abstract: A speed sensor for use in measuring the speed of rotation of a rotationally salient rotating member The speed sensor comprises an electrode and a sensor circuit. The sensor circuit comprises a constant voltage source for supplying a voltage to the electrode to generate an electric field in a dielectric medium. A current detector detects current flow between the constant voltage source and the electrode due to perturbation of the electric field by passage of at least one salient feature of the rotating member through the electric field as the rotating member rotates. The current detector outputs a first signal modulated at a frequency corresponding to the frequency of perturbation of the electric field. The first signal is amplified to produce an amplified signal modulated at a frequency corresponding to the frequency of perturbation of the electric field.
    Type: Application
    Filed: November 16, 2009
    Publication date: June 17, 2010
    Inventors: Calvin Cox, Thomas W. Bach
  • Publication number: 20080298784
    Abstract: A method and circuit for determining the speed and/or counting the revolutions of brush and commutator motors is described. The method and circuitry detects signals present on the windings of the motor due to commutation that occurs at the brushes and commutator of the motor. This method can be used to simply monitor & indicate the motor speed and revolutions or to form the basis of a motor control.
    Type: Application
    Filed: June 4, 2007
    Publication date: December 4, 2008
    Inventor: Mark Allen Kastner
  • Patent number: 7341321
    Abstract: A rotation detecting device that includes an electric power generator having a stator and a rotor, said rotor having a plurality of alternating opposite magnetic poles in a circumferential direction of the rotor, at least a first magnetic sensor mounted on either the stator or a support member for supporting the stator and operable to detect the alternating opposite magnetic poles in the rotor; and an electric power supply circuit for utilizing an electric power generated by the electric power generator as an electric power source for the at least first magnetic sensor.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: March 11, 2008
    Assignee: NTN Corporation
    Inventors: Toru Takahashi, Koichi Okada, Kenichi Iwamoto, Hiroaki Ohba
  • Patent number: 7304470
    Abstract: A fan operating status monitoring system includes a detecting module to detect pulsation currents generated by the rotation of a fan, and further convert the detected pulsation currents to voltage signals, thereby allowing a differential magnifying module, a first processing module, and a control module to process the pulse wave signals in orders to measure the rotation speeds of the fan. Also, the second processing module and the control module can process the pulsation electric current signals so as to calculate the working currents of the fan, thereby expanding the measuring range of the rotation speeds of the fan, and at the same time, effectively controlling the operating status of the fan.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: December 4, 2007
    Assignee: Inventec Corporation
    Inventors: Wei-I Chen, Chin-Lung Lien
  • Publication number: 20070273363
    Abstract: A ripple detecting device for detecting a ripple from an armature current outputted from a motor by overlapping a low band noise having a frequency of one/n (wherein ā€œnā€ is a natural number more than 1) includes an initial ripple detecting device for detecting a cycle of the ripple in advance, a feature detecting device for detecting a feature of the ripple from the armature current outputted from the motor. The ripple detecting device further includes a ripple detecting control device for detecting the ripple by comparing the feature of the ripple with the low band noise having the frequency of one/n detected by the feature detecting device at a time before the present time with the feature of the ripple detected by the feature detecting device at the present time and judging that a ripple is generated when the features of the time before the present time and the present time present are resembled.
    Type: Application
    Filed: May 22, 2007
    Publication date: November 29, 2007
    Applicant: AISINSEIKI KABUSHIKI KAISHA
    Inventors: Muneaki Kurimoto, Hitoshi Ishikawa, Eiichiro Shigehara
  • Patent number: 7265538
    Abstract: A method and a device for measuring the speed of a pulse-activated electric motor are described. According to this method, the motor is fully activated at time intervals to be determined for a defined measuring time by the circuit element provided for timing and, in this time, the frequency of the current ripples, which is proportional to the motor speed, is measured. A current-proportional voltage measuring device is located on the circuit element, on whose load side are located an amplifier, filters, and an evaluation circuit in the form of a comparator for determining the frequency of the current ripples flowing in a measured phase during which the motor is fully activated.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: September 4, 2007
    Assignee: Robert Bosch GmbH
    Inventors: Marc Micke, Holger Sievert, Juergen Hachtel, Guenther Hertlein
  • Patent number: 7221152
    Abstract: A method for determining the speed and position of a rotor of a salient-pole permanent magnet synchronous machine, the method comprising the steps of creating a voltage model (41) on a permanent magnet synchronous machine, forming a voltage reference (us,ref) for a stator of the permanent magnet synchronous machine, determining stator currents (is) of the permanent magnet synchronous machine, calculating a rotor angular speed (42) from the voltage reference (us,ref) and the stator currents (is) using the voltage model (41). The method further comprises the steps of forming with signal injection a position tracking signal (?) of the rotor of the permanent magnet synchronous machine, forming a rotor angular speed estimate ({circumflex over (?)}m) from the calculated rotor angular speed (42) and the rotor position tracking signal (?), forming a rotor position angle estimate ({circumflex over (?)}m) from the formed rotor angular speed estimate ({circumflex over (?)}m) and the rotor position tracking signal (?).
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: May 22, 2007
    Assignee: ABB OY
    Inventor: Antti Piippo
  • Patent number: 7187180
    Abstract: A method and motor controller for sensing motor winding current. An FET drive transistor has its ON resistance periodically increased to about five times the normal ON resistance for short sensing intervals during motor drive. An analog-to-digital converting senses the voltage across this FET during the sensing intervals. The resulting digital signal is used to calculate motor current. The time at high ON resistance is much less than the time at normal. The ON resistance can be changed using two FETs or one FET with gate fingers over differing parts of the channel region.
    Type: Grant
    Filed: January 31, 2006
    Date of Patent: March 6, 2007
    Assignee: Texas Instruments Incorporated
    Inventor: Jim D. Childers
  • Patent number: 7030580
    Abstract: A transient response system includes a power source operable to generate a power output and a transmission operatively coupled to the power source. The transient response system also includes a generator operatively coupled to the power source and a controller in communication with the generator and at least one of the power source and the transmission. The controller is operable to receive at least one input having a value indicative of a change in load on the power source and operable to cause the generator to remove power from the power output at a rate corresponding to the value of the at least one input.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: April 18, 2006
    Assignee: Caterpillar Inc.
    Inventor: Brian D. Hoff
  • Publication number: 20040124831
    Abstract: A method and a device for measuring the speed of a pulse-activated electric motor are described. According to this method, the motor is fully activated at time intervals to be determined for a defined measuring time by the circuit element provided for timing and, in this time, the frequency of the current ripples, which is proportional to the motor speed, is measured. A current-proportional voltage measuring device is located on the circuit element, on whose load side are located an amplifier, filters, and an evaluation circuit in the form of a comparator for determining the frequency of the current ripples flowing in a measured phase during which the motor is fully activated.
    Type: Application
    Filed: September 12, 2003
    Publication date: July 1, 2004
    Inventors: Marc Micke, Holger Sievert, Juergen Hachtel, Guenther Hertlein
  • Patent number: 6718273
    Abstract: A method for generating manipulated variables for the direct-axis and cross voltage, respectively, to represent the flux-forming current ID and torque-forming current IQ in field-oriented control of asynchronous machines, taking into account the stator voltage drop and steady-state internal voltage. The steady-state internal voltage is calculated on the basis of reference variables of the currents.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: April 6, 2004
    Assignee: Robert Bosch GmbH
    Inventors: Harald Tschentscher, Martin Eisenhardt
  • Patent number: 6703824
    Abstract: A device for measuring the power of a motor, having a measurer for measuring the current sent to the motor and a measurer for measuring the voltage, related to the current, that is sent to the motor, a rephaser for rephasing the waveform of the voltage measured by the voltage measurer and a multiplier suitable to multiply the current measured by the current measurer with the voltage rephased by the rephaser, the output signal of the multiplier being processed in order to obtain active power.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: March 9, 2004
    Assignee: Z. Bavelloni S.p.A.
    Inventor: Franco Bavelloni
  • Patent number: 6674191
    Abstract: A motor actuator control system includes a motor actuator having a motor, an output shaft for outputting rotation of the motor at reduced speed, and a gear train for transmitting rotation to the output shaft while reducing rotataional speed. The system further includes a first detector detecting current surges generated when contact between a commutator and brushes in the motor is broken, a second detector detecting a predetermined rotational position of a gear, and a control unit for controlling the motor on the basis of signals from the first detector and signals from the second detector. When the predetermined rotational position is detected, the position and the count of the current surges are correlated. Then, the motor is driven until the count reaches a predetermined number to rotate the output shaft to another predetermined rotational position.
    Type: Grant
    Filed: March 11, 2002
    Date of Patent: January 6, 2004
    Assignee: Asmo Co., Ltd.
    Inventor: Yukinobu Kujira
  • Patent number: 6671639
    Abstract: The present invention relates to a method of determining a speed of rotation of a squirrel-cage motor, wherein samples from the current taken by the squirrel-cage motor are collected by an electric current measuring device at a predetermined sampling frequency for a measurement period, the samples being stored as measurement data of a fixed format. The method is characterized by comprising the step of determining the rotation speed of the squirrel-cage motor from the measurement data by determining the base frequency and side frequencies of the electric current taken by the squirrel-cage motor, the rotation speed frequency of the squirrel-cage motor being obtained by subtracting the lower side frequency from the higher side frequency and by dividing the difference thus obtained by two.
    Type: Grant
    Filed: September 4, 2002
    Date of Patent: December 30, 2003
    Assignee: ABB Research Ltd.
    Inventors: Kari Saarinen, Michal Orkisz
  • Patent number: 6532405
    Abstract: An exemplary embodiment of the invention is a method for detecting a potentially locked axle on a vehicle propelled by an AC motor. The method includes conducting a speed test by estimating axle speed and comparing estimated axle speed to measured vehicle speed. The existence of a potential locked axle condition is determined based on the comparing of estimated axle speed to measured vehicle speed. Additional tests are disclosed for determining a potential locked axle condition and a sensor fault condition.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: March 11, 2003
    Assignee: General Electric Company
    Inventors: Ajith Kuttannair Kumar, Jeffrey Louis Daigle
  • Patent number: 6366077
    Abstract: An apparatus and method for detecting a rate of rotation of a DC spindle motor without using an additional frequency generation (FG) signal generator in electronic equipment using the DC spindle motor. The apparatus detects the rate of rotation of a DC motor based on a current applied to the DC motor without using an additional FG signal generator in electronic equipment employing the DC motor and performs control corresponding to a detected result, thereby lowering costs and improving a manufacturing process in comparison with a conventional method employing a brushless motor to detect the rate of rotation of a motor.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: April 2, 2002
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Young-han Kim
  • Patent number: 6323779
    Abstract: A pedal stroke sensor a rotor that rotates with a brake pedal with a pair of brushes fixed on the rotor. The brushes are inclined oppositely to each other along rotating direction of the rotor and contact a circuit printed on a circuit board to generate output voltages V1A and V1B which increase and decrease oppositely to each other in response to the brushes sliding over the circuit board. A difference signal |V1A−V1B| is output as a signal corresponding to pedal stroke S of the brake pedal. When any kind of vibration changes the contacting positions of the brushes on the board, the output voltages V1A, V1B change in the same direction, so that, even if the contacting positions of the brushes change because of a vibration, the difference signal |V1A−V1B| does not change greatly, allowing accurate detection of the position of the brake pedal even if such vibrations occur.
    Type: Grant
    Filed: December 3, 1999
    Date of Patent: November 27, 2001
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Fumitada Murakami, Osamu Kouketsu, Masanori Hirose
  • Patent number: 6222362
    Abstract: A method is presented for detecting the position and the direction of motion of a movably mounted part on an electric motor that makes provision not only for a single-channel sensor but also a measuring arrangement for the motor current and the rectified motor current by means of which the motor current is activated after operating switching devices to reverse the polarity of the voltage applied to the motor to cause a reversal of the direction of motion. The measuring arrangement establishes from the variation of the motor current over time the point of time of the motor current maximum and transmits this to the evaluation logic. The point of time of the actual reversal of the direction of motion is derived from the point of time of the motor current. Preferably, the current is measured as a reference current value even before falling through the zero crossing.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: April 24, 2001
    Assignee: Temic Telefunken Microelectronics GmbH
    Inventors: Wolfgang Schulter, Dieter Driendl, Erwin Kessler, Stephan Kimpfler, Kurt Kleiner
  • Patent number: 6208132
    Abstract: A sensing coil affixed to the outside of an induction motor housing uses flux signals from the motor to measure motor speed. In particular, components of the rotor current are measured and compared to analysis from stator fundamentals and sidebands to determine the true rotor frequency which can then be used to determine the motor speed. A shield and/or a compensating coil can optionally be used to filter out extraneous signal noise.
    Type: Grant
    Filed: November 2, 1998
    Date of Patent: March 27, 2001
    Assignee: General Electric Company
    Inventors: Gerald Burt Kliman, John Andrew Mallick
  • Patent number: 6172473
    Abstract: A device for determining a rotational number of an electric dc motor which drives a moving body of an automobile accessory such a sunroof, or a glass pane of a power window includes a switched capacitance filter for eliminating noise from the motor, a cutoff frequency of the switched capacitance filter being dependent on a clock input thereof; a pulse shaping circuit for generating a ripple pulse signal indicative of the rotational number of the motor by wave-shaping an output of the switched capacitance filter; and a pulse generating circuit providing an output pulse signal so as to establish a condition wherein the frequency of the ripple pulse signal is equalized to the cutoff frequency of the a switched capacitance filter.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: January 9, 2001
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Toshimitsu Oka, Koji Aoki, Hideyuki Kanie, Hitoshi Ishikawa
  • Patent number: 6150777
    Abstract: A direct current motor for use in a closed-loop control system is disclosed that includes a rotating commutator having a plurality of slots, a plurality of windings, the number of windings that conduct current corresponding to one less than the number of slots of the commutator, and a plurality of brushes that are configured so that application of a direct current voltage across the brushes results in a current flow in at least one of the windings which causes the commutator to rotate. Continuous application of the direct current voltage across the brushes causes the current to flow in a varying number of the current conducting windings as the commutator continues to rotate, the number periodically varying from all of the current conducting windings to the at least one current conducting winding.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: November 21, 2000
    Assignee: Hewlett-Packard Company
    Inventor: Daniel Lander
  • Patent number: 6144179
    Abstract: The method for determining the rotational speed and/or the angle of rotation of mechanically commutated d.c. motors from the variation with respect to time of the ripple of the motor current occurring during commutation is supplemented and checked by a motor state model that functions in parallel to it and is based on the electromechanical motor equations. A probable value of the actual speed is extrapolated from the motor current and the motor voltage and a permissible reference time range is determined for the next commutation. If no commutation time can be established in the reference time range, the extrapolated value is used. Otherwise, the current speed is determined precisely from the commutation time measured in the reference time range. The load-dependent motor constant for the motor state model can be preset as a fixed value or it can be adjusted to the actual speed after commutation processes have been detected.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: November 7, 2000
    Assignee: Temic Telefunken microelectronic GmbH
    Inventors: Erwin Kessler, Wolfgang Schulter
  • Patent number: 6144198
    Abstract: A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is squared. The squared outputs associated with each winding are combined, with the square root being taken of such combination, to produce a DC output proportional only to the rate of rotation of the motor's shaft.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: November 7, 2000
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: David E. Howard, Dennis A. Smith
  • Patent number: 6130533
    Abstract: A fan speed detecting circuit includes a resistor installed in the grounding line of the power circuit of the DC fan motor of a cooling fan, a capacitor, a diode connected between the resistor and the capacitor, and a comparator having an inverter terminal connected to the output end of the diode through the capacitor and a non-inverter terminal connected in parallel to the input end of the diode, wherein a transient pulse current is produced at the resistor upon operation of the DC fan motor, causing the comparator to output a pulse frequency wave indicative of the revolving speed of the DC fan motor.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: October 10, 2000
    Assignee: D-Link Corporation
    Inventors: Chung-Wang Lee, Ming-Chun Su, Yu-Ping Chung
  • Patent number: 6127820
    Abstract: A process and circuit arrangement are disclosed for determining the speed of a direct current motor (10). The motor data influencing the speed (n) of the motor (10) depend on the operating state of the motor (10), and this dependence is compensated during operation the direct current motor (10) operation during determination of the speed (n).
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: October 3, 2000
    Assignee: Robert Bosch GmbH
    Inventors: Martin Kessler, Karl-Heinrich Preis
  • Patent number: 6084398
    Abstract: A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is integrated and multiplied by the back-emf associated with an adjacent winding. The multiplied outputs associated with each winding are combined to produce a directionally sensitive DC output proportional only to the rate of rotation of the motor's shaft.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: July 4, 2000
    Assignee: The United States of America as represented by the Administrator of the Nautical Aeronautics and Space Administation
    Inventor: David E. Howard
  • Patent number: 6081112
    Abstract: A circuit and method for measuring a back EMF voltage of a voice coil in a mass storage device, or the like, includes an amplifier connected across the coil to produce an output signal proportional to a voltage across the coil and a circuit connected to selectively connect the output signal of the amplifier to a circuit output when a driving current is not applied to said coil. A sample window is generated after drive currents within the coil have been allowed to decay to zero, and between a time during which a PWM signal changes from negative to positive and a time when the PWM waveform crosses a voltage error value.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: June 27, 2000
    Assignee: STMicroelectronics, Inc.
    Inventors: Francesco Carobolante, Paolo Menegoli
  • Patent number: 6060879
    Abstract: A current magnitude sensing circuit for detecting a malfunction of a DC brushless fan. The current magnitude sensing circuit detects drops in the current magnitude in windings of a fan motor. Depending on the frequency of the current drops in the fan current, the current magnitude sensing circuit outputs either a high or a low voltage signal. The current magnitude sensing circuit operates by charging a capacitor beyond a certain voltage and thereby providing a high fan fail output signal when a fan is spinning too slowly for proper cooling of a device. Another capacitor is charged at a different time constant for setting the fan fail output of the current magnitude circuit low for indicating that the fan is spinning sufficiently fast.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: May 9, 2000
    Assignee: CORE Engineering Inc.
    Inventor: Georg A. Mussenden
  • Patent number: 6054791
    Abstract: A direct current motor for use in a closed-loop control system is disclosed that includes a rotating commutator having a plurality of slots, a plurality of windings, the number of windings that conduct current corresponding to one less than the number of slots of the commutator, and a plurality of brushes that are configured so that application of a direct current voltage across the brushes results in a current flow in at least one of the windings which causes the commutator to rotate. Continuous application of the direct current voltage across the brushes causes the current to flow in a varying number of the current conducting windings as the commutator continues to rotate, the number periodically varying from all of the current conducting windings to the at least one current conducting winding.
    Type: Grant
    Filed: September 17, 1998
    Date of Patent: April 25, 2000
    Assignee: Hewlett-Packard
    Inventor: Daniel Lander
  • Patent number: 5714862
    Abstract: The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: February 3, 1998
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: Harvey E. Mikesell, Eric Lucy
  • Patent number: 5689181
    Abstract: A brushless motor speed detecting apparatus includes a stator having three-phase driving coils which are energized reciprocally in the positive and negative directions, a rotor having magnetic poles, three position detectors for obtaining three-phase output signals corresponding to the rotation of the rotor, a first synthesizing circuit for synthesizing the output signals of the three position detectors, mode switching circuit for forming an energizing mode switching signal according to the output signal of the first synthesizing circuit, a driving circuit for supplying currents to the driving coils by switching an energizing mode from a first energizing mode to a second energizing and vice versa according to the output signal of the mode switching circuit, and a second synthesizing circuit for synthesizing a speed signal by detecting in the non-energizing section of the first energizing mode the induced electromotive voltages generated in the driving coils as the rotor rotates to base the synthesis of the sp
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: November 18, 1997
    Assignee: Kabushiki Kaisha Sankyo Seiki Seisakusho
    Inventors: Hayato Naito, Nobuki Kokubo
  • Patent number: 5661386
    Abstract: A method and apparatus for assessing the efficiency of an in-service motor. The operating characteristics of the in-service motor are remotely measured. The operating characteristics are then applied to an equivalent circuit for electrical motors. Finally the equivalent circuit is evaluated to determine the performance characteristics of said in-service motor. Based upon the evaluation an individual is able to determine the rotor speed, power output, efficiency, and toque of the in-service motor. Additionally, an individual is able to confirm the calculations by comparing measured values with values obtained as a result of the motor equivalent circuit evaluation.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: August 26, 1997
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: John D. Kueck, Pedro J. Otaduy
  • Patent number: 5654620
    Abstract: The present invention provides a sensorless circuit for detecting rotational speed of a rotor in an induction motor. The circuit includes a switch between the AC source driving the motor and a motor phase winding. When the switch is closed, there is developed across the phase winding a voltage waveform from the AC source. When the switch is subsequently opened, there is developed across the winding a residual voltage waveform induced by the rotor. The speed of the motor is determined by measuring a time interval between selected points on the voltage waveform.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: August 5, 1997
    Assignee: MagneTek, Inc.
    Inventor: Phillip G. Langhorst