Patents by Inventor Qixiang Lu

Qixiang Lu 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).

  • Current sensor having shunt resistor and clamper diode for motor control
    Patent number: 7629787
    Abstract: The present invention provides an improved motor current sensor and methods thereof. A first embodiment of the present invention provides a circuit having a signal transfer unit for receiving first and second input signals from opposing terminals of a shunt resistor and a signal conditioner unit for conditioning output signals from the signal transfer unit for a low power control unit. A second embodiment of the present invention provides a circuit having a signal conditioner unit for receiving first and second input signals from opposing terminals of a shunt resistor and delivering output signals to a signal transfer unit and finally to a level shifter for providing first and second voltage signals to a control unit.
    Type: Grant
    Filed: January 3, 2007
    Date of Patent: December 8, 2009
    Inventor: Qixiang Lu
  • Apparatus and method for isolating noise from a signal
    Patent number: 7498806
    Abstract: A circuit is provided for isolating noise from an input signal to an Analog/Digital (A/D) converter. The circuit includes a plurality of multiplexers and a capacitor connected between the poles of two Single-Pole Multi-Throw (SPMT) multiplexers. A method is also provided for isolating noise from an input signal to the A/D converter using the circuit. The method includes storing a charge in the capacitor and discharging the charge to an A/D converter used to control a system or device.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: March 3, 2009
    Assignee: SPX Corporation
    Inventor: Qixiang Lu
  • Current Sensor and Method for Motor Control
    Publication number: 20080157752
    Abstract: The present invention provides an improved motor current sensor and methods thereof. A first embodiment of the present invention provides a circuit having a signal transfer unit for receiving first and second input signals from opposing terminals of a shunt resistor and a signal conditioner unit for conditioning output signals from the signal transfer unit for a low power control unit. A second embodiment of the present invention provides a circuit having a signal conditioner unit for receiving first and second input signals from opposing terminals of a shunt resistor and delivering output signals to a signal transfer unit and finally to a level shifter for providing first and second voltage signals to a control unit.
    Type: Application
    Filed: January 3, 2007
    Publication date: July 3, 2008
    Inventor: Qixiang Lu
  • Apparatus and method for isolating noise from a signal
    Publication number: 20060284667
    Abstract: A circuit is provided for isolating noise from an input signal to an Analog/Digital (A/D) converter. The circuit includes a plurality of multiplexers and a capacitor connected between the poles of two Single-Pole Multi-Throw (SPMT) multiplexers. A method is also provided for isolating noise from an input signal to the A/D converter using the circuit. The method includes storing a charge in the capacitor and discharging the charge to an A/D converter used to control a system or device.
    Type: Application
    Filed: June 20, 2005
    Publication date: December 21, 2006
    Inventor: Qixiang Lu