1
Chao Bi
Quan Jiang, Chao Bi: Method to detect the true zero-crossing points of the phase back EMF for sensorless control of brushless DC motors. April 12, 2005: US06879124 (14 worldwide citation)

In the present system and method, ZCP level signals of each phase voltage are first obtained. Among the detected ZCP level signals, some ZCPs are generated by phase back EMF, which are true ZCPs and other ZCPs by commutations, which are false ZCPs. The duration of the false ZCP level outputs varies ...


2
Kiyoshi Nagasawa, Toru Inoue, Susumu Kashiwazaki: Control system for brushless DC motor. Hitachi, Antonelli Terry & Wands, December 8, 1987: US04712050 (94 worldwide citation)

A control system for brushless DC motors detects counter electromotive force voltages induced in motor windings and produces rotor position detection signals from the counter electromotive force voltages. The maximum value of an input DC current to a motor drive circuit is held and the phase of the ...


3
Harold J Faig, Ronald M Sparer: Injection molding machines having a brushless DC drive system. Cincinnati Milacron, C Richard Eby, January 29, 1991: US04988273 (65 worldwide citation)

An injection molding machine utilizing brushless DC motors in its servomechanism drive systems. Brushless DC motors provide a cost effective high power drive system which has the simplicity of control of brush-type DC motors. By utilizing higher resolution encoders and controlling pressure with the ...


4
Raymond G Gauthier, David M Lancisi, Gregory L Morris: Method and apparatus for controlling brushless DC motors in implantable medical devices. Heartware, John P White Esq, Cooper & Dunham, November 21, 2006: US07138776 (59 worldwide citation)

Methods and apparatus for controlling a polyphase motor in implantable medical device applications are provided. In one embodiment, the polyphase motor is a brushless DC motor. The back emf of a selected phase of the motor is sampled while a drive voltage of the selected phase is substantially zero. ...


5
Shuzo Moroto, Mutumi Kawamoto: Power supply cut off apparatus. Kabushiki Kaisha Equos Research, Sandler Greenblum & Bernstein, February 14, 1995: US05389824 (51 worldwide citation)

A power supply cut off apparatus is provided in which a DC power supply voltage supplied from a main power supply is converted into an AC current by an inverter of a driver, and brushless DC motors are driven by the converted current, during normal operation. In the normal operation, an abnormal sta ...


6
R William Kneifel II, Stephen T Walsh, Thomas W Minnich, Robert M Crovella, A Harold Morser: Method and apparatus for torque ripple compensation. Cincinnati Milacron, John W Gregg, August 22, 1995: US05444341 (44 worldwide citation)

Torque ripple in brushless DC motors is reduced by compensation of signals controlling energization of motor stator windings. Motor current magnitude is compensated in response to compensation factor values correlated to the ratio of actual torque to ideal torque at constant current at various relat ...


7
Hans M Leuthold, Felix De Herrera: Phase commutation circuit for brushless DC motors using a spike insensitive back EMF detection method. Seagate Technology, Flehr Hohbach Test Albritton & Herbert, October 15, 1991: US05057753 (42 worldwide citation)

Apparatus for controlling phase commutation of a brushless DC motor. The apparatus is comprised of a back EMF detection technique to determine the current position of the rotor, an error rejection circuit to prohibit commutation noise from causing errors in determining the present rotor position, a ...


8
Thomas Minnich, Alfred H Morser, Stanley L Myers, Stephen T Walsh: Motor control apparatus and method. Cincinnati Milacron, John W Gregg, February 16, 1993: US05187417 (40 worldwide citation)

An apparatus and method for controlling brushless DC motors are provided. Velocity loop control is performed digitally to produce current commands at a high frequency loop closure interval. Commutation of field coil current is controlled in response to current commutation pattern control signals pro ...


9
Robert A Administrator of the National Aeronautics and Space Administration with respect to an invention of Frosch, Lester S Hieda: Controller for computer control of brushless DC motors. Monte F Mott, John R Manning, Paul F McCaul, February 3, 1981: US04249116 (37 worldwide citation)

An improved motor speed and torque controller for brushless DC motors which provides an unusually smooth torque control arrangement. The controller provides a means for controlling a current waveform in each winding of a brushless DC motor by synchronization of an excitation pulse train from a progr ...


10
Toshio Inaji, Hiroshi Minakuchi, Yoshiaki Igarashi: Driving circuit for brushless DC motors. Matsushita Electric Industrial, Wenderoth Lind & Ponack, December 30, 1986: US04633150 (34 worldwide citation)

A driving circuit for a brushless DC motor having a small amount of torque ripple comprises a magnetic pole position detecting circuit for detecting positions of magnetic poles of a rotor magnet and delivering polyphase signals indicating the positions, a rectifier adder circuit for producing a sum ...