Patents by Inventor Laird Bolt

Laird Bolt has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Hall sensor alignment for BLDC motor
    Patent number: 7423396
    Abstract: A technique for determining an alignment error of a Hall sensor location in a brushless DC motor drive, by measuring the back EMF waveform, preferably while the motor is coasting. According to the technique, an angular offset is calculated between a selected BEMF waveform and a selected Hall signal. Such offsets are preferably calculated for each phase individually. The offsets may be advantageously stored in the motor control unit and used to adjust the output motor control signals for maximum torque.
    Type: Grant
    Filed: June 10, 2005
    Date of Patent: September 9, 2008
    Assignee: International Rectifier Corporation
    Inventor: Laird Bolt
  • Method and apparatus for reconstructing motor current from DC bus current
    Patent number: 6984953
    Abstract: In a PWM space vector modulation inverter motor drive system, PWM cycles are modified to permit motor phase currents to be reconstructed as observable on the DC bus link. The PWM cycles are modified near sector boundaries so that measurements taken at the DC bus link correspond to actual motor phase currents. With this technique, a single DC bus current measure can be used to reconstruct all motor phase currents, while also providing fault protection.
    Type: Grant
    Filed: January 20, 2004
    Date of Patent: January 10, 2006
    Assignee: International Rectifier Corporation
    Inventors: Jean Quirion, Laird Bolt
  • Hall sensor alignment for BLDC motor
    Publication number: 20050275361
    Abstract: A technique for determining an alignment error of a Hall sensor location in a brushless DC motor drive, by measuring the back EMF waveform, preferably while the motor is coasting. According to the technique, an angular offset is calculated between a selected BEMF waveform and a selected Hall signal. Such offsets are preferably calculated for each phase individually. The offsets may be advantageously stored in the motor control unit and used to adjust the output motor control signals for maximum torque.
    Type: Application
    Filed: June 10, 2005
    Publication date: December 15, 2005
    Inventor: Laird Bolt
  • Method and apparatus for reconstructing motor current from DC bus current
    Publication number: 20040195995
    Abstract: In a PWM space vector modulation inverter motor drive system, PWM cycles are modified to permit motor phase currents to be reconstructed as observable on the DC bus link. The PWM cycles are modified near sector boundaries so that measurements taken at the DC bus link correspond to actual motor phase currents. With this technique, a single DC bus current measure can be used to reconstruct all motor phase currents, while also providing fault protection.
    Type: Application
    Filed: January 20, 2004
    Publication date: October 7, 2004
    Inventors: Jean Quirion, Laird Bolt