Patents by Inventor Yan-Fei Liu

Yan-Fei Liu 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).

  • Patent number: 9337641
    Abstract: An embodiment high efficiency power regulator comprises a three-terminal converter and a protection device. The three-terminal converter comprises a first terminal coupled to a positive terminal of an input voltage bus, a second terminal coupled to a positive terminal of an output voltage bus and a third terminal coupled to the protection device. The protection device comprises an inrush current limiting element connected in series with a reverse polarity protection device.
    Type: Grant
    Filed: April 15, 2014
    Date of Patent: May 10, 2016
    Assignee: Futurewei Technologies, Inc.
    Inventors: Hengchun Mao, Yan-Fei Liu, Renhua Wu
  • Publication number: 20150249394
    Abstract: Provided are methods and circuits for a resonant converter comprising at least one switch-controlled capacitor, wherein the at least one switch-controlled capacitor controls a resonant frequency of the resonant tank circuit. Provided are constant and variable switching frequency embodiments, and full-wave and half-wave switch-controlled capacitor embodiments. Also provided are interleaved resonant converters based on constant and variable switching frequency, and full-wave and half-wave switch-controlled capacitor resonant converter embodiments. Interleaved embodiments overcome load sharing problems associated with prior interleaved resonant converters and enable phase shedding to improve light load efficiency.
    Type: Application
    Filed: September 13, 2013
    Publication date: September 3, 2015
    Inventors: Yan-Fei Liu, Zhiyuan Hu
  • Patent number: 9122287
    Abstract: Dual frequency control of first and second pairs of switches of a buck-boost regulator with pass through band is disclosed. In buck and boost modes respectively a first pair of the switches is operated at high frequency and a second pair of the switches is operated at low frequency. In pass through mode, both pairs of switches are operated at low frequency. Dual frequency control and operation of the pairs of switches enables current sharing between positive and negative power leads in buck, boost and pass-through modes.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: September 1, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Hengchun Mao, Yan-Fei Liu
  • Publication number: 20150166857
    Abstract: Epoxy adhesive compositions contain a heat-activatable catalyst. The heat-activatable catalyst includes a tertiary amine catalyst and a novolac resin that has a weight average molecular weight of at least 3000. One-component epoxy adhesive formulations that contain the heat-activatable catalyst have unexpectedly good storage stability.
    Type: Application
    Filed: March 3, 2015
    Publication date: June 18, 2015
    Inventors: Ming Ming, Shaoguang Feng, Yan Fei Liu, Robert DJ Froese, Andreas Lutz, Glenn G. Eagle, Gary L. Jialanella, Eric E. Cole, Michael R. Golden
  • Patent number: 9000120
    Abstract: Epoxy adhesive compositions contain a heat-activatable catalyst. The heat-activatable catalyst includes a tertiary amine catalyst and a novolac resin that has a weight average molecular weight of at least 3000. One-component epoxy adhesive formulations that contain the heat-activatable catalyst have unexpectedly good storage stability.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: April 7, 2015
    Assignee: Dow Global Technologies LLC
    Inventors: Ming Ming, Shaoguang Feng, Yan Fei Liu, Andreas Lutz, Robert D. Froese, Glenn G. Eagle, Gary L. Jialanella, Eric E. Cole, Michael R. Golden
  • Publication number: 20150001853
    Abstract: An apparatus and method for generating electrical power from a user comprises a motion capture apparatus that captures at least a portion of motion of a pair of limbs of the user; a motion integrator mechanically coupled to the motion capture apparatus such that captured motion of the pair of limbs is transferred to the motion integrator, and the motion integrator produces an output motion; an adaptive controller, and an electrical generator mechanically coupled to the output motion of the motion integrator; wherein the electrical generator generates electrical power from the output motion of the motion integrator. The apparatus may be adapted to be carried on the user's back. In one embodiment the apparatus is incorporated into a backpack.
    Type: Application
    Filed: June 19, 2014
    Publication date: January 1, 2015
    Inventors: Michael Y. Shepertycky, Qingguo Li, Yan-Fei Liu
  • Publication number: 20140252973
    Abstract: Provided are circuits and methods for use with a power supply that provides a main output including a main DC voltage having a first AC voltage ripple, or a main DC current having a first AC current ripple. A ripple cancellation converter provides a second AC voltage ripple connected in series with the main output, such that the first AC voltage ripple is substantially cancelled; or a second AC current ripple connected in parallel with the main output, such that the first AC current ripple is substantially cancelled. As a result, substantially ripple-free DC output power is provided.
    Type: Application
    Filed: October 17, 2012
    Publication date: September 11, 2014
    Applicant: Queen's University at Kingston
    Inventor: Yan-Fei Liu
  • Publication number: 20140226246
    Abstract: An embodiment high efficiency power regulator comprises a three-terminal converter and a protection device. The three-terminal converter comprises a first terminal coupled to a positive terminal of an input voltage bus, a second terminal coupled to a positive terminal of an output voltage bus and a third terminal coupled to the protection device. The protection device comprises an inrush current limiting element connected in series with a reverse polarity protection device.
    Type: Application
    Filed: April 15, 2014
    Publication date: August 14, 2014
    Applicant: FUTUREWEI TECHNOLOGIES, INC.
    Inventors: Hengchun Mao, Yan-Fei Liu, Renhua Wu
  • Patent number: 8717717
    Abstract: An embodiment high efficiency power regulator comprises a three-terminal converter and a protection device. The three-terminal converter comprises a first terminal coupled to a positive terminal of an input voltage bus, a second terminal coupled to a positive terminal of an output voltage bus and a third terminal coupled to the protection device. The protection device comprises an inrush current limiting element connected in series with a reverse polarity protection device.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: May 6, 2014
    Assignee: Futurewei Technologies, Inc.
    Inventors: Hengchun Mao, Yan-Fei Liu, Renhua Wu
  • Publication number: 20130318366
    Abstract: Dual frequency control of first and second pairs of switches of a buck-boost regulator with pass through band is disclosed. In buck and boost modes respectively a first pair of the switches is operated at high frequency and a second pair of the switches is operated at low frequency. In pass through mode, both pairs of switches are operated at low frequency. Dual frequency control and operation of the pairs of switches enables current sharing between positive and negative power leads in buck, boost and pass-through modes.
    Type: Application
    Filed: May 25, 2012
    Publication date: November 28, 2013
    Inventors: Hengchun MAO, Yan-Fei LIU
  • Publication number: 20130093403
    Abstract: Methods and circuits are described herein which may be used to improve the unloading transient response of a DC-DC converter. In some embodiments the transient response may be improved by improving the way MOSFET switches in the buck converter are controlled at the point in time when a current transient is detected, and subsequently during the transient, in such a way that the impact of the current transient is mitigated. In other embodiments an auxiliary current source is used to provide rapid transient response required by the overall power converter, leaving the main portion of the DC-DC converter to provide long term stability.
    Type: Application
    Filed: September 10, 2012
    Publication date: April 18, 2013
    Inventors: Liang Jia, Yan-Fei Liu
  • Publication number: 20130090431
    Abstract: Epoxy adhesive compositions contain a heat-activatable catalyst. The heat-activatable catalyst includes a tertiary amine catalyst and a novolac resin that has a weight average molecular weight of at least 3000. One-component epoxy adhesive formulations that contain the heat-activatable catalyst have unexpectedly good storage stability.
    Type: Application
    Filed: June 27, 2011
    Publication date: April 11, 2013
    Inventors: Ming Ming, Shaoguang Feng, Yan Fei Liu, Andreas Lutz, Robert D. Froese, Glenn G. Eagle, Gary L. Jialanella, Eric E. Cole, Michael R. Golden
  • Publication number: 20130033786
    Abstract: An embodiment high efficiency power regulator comprises a three-terminal converter and a protection device. The three-terminal converter comprises a first terminal coupled to a positive terminal of an input voltage bus, a second terminal coupled to a positive terminal of an output voltage bus and a third terminal coupled to the protection device. The protection device comprises an inrush current limiting element connected in series with a reverse polarity protection device.
    Type: Application
    Filed: August 4, 2011
    Publication date: February 7, 2013
    Applicant: FutureWei Technologies, Inc.
    Inventors: Hengchun Mao, Yan-Fei Liu, Renhua Wu
  • Publication number: 20120068683
    Abstract: Described herein are methods and circuits for driving a power switching device of a power converter. The methods and circuits include providing a negative gate to source voltage to the power switching device during an off transition of the power switching device, wherein the negative gate to source voltage is provided independent of one or more switching element for driving the power switching device; wherein body diode conduction by the one or more switching element is mitigated; wherein a circuit connected in parallel with the gate and source of the power switching device is used to set or define the negative gate to source voltage.
    Type: Application
    Filed: September 16, 2011
    Publication date: March 22, 2012
    Inventors: Yan-Fei LIU, Zhiliang ZHANG, Jizhen FU
  • Publication number: 20120063175
    Abstract: Provided are circuits and methods for driving the synchronous rectifier (SR) of a power converter. A non-linear voltage sense compensator is applied across the drain and source of the SR, and a sense signal is provided to the SR driver sense input, such that false triggering of the SR is effectively eliminated. In addition, the voltage sense compensator ensures that the SR is turned on as soon as its current starts to flow and is turned off when its current falls to zero. The embodiments described herein may be incorporated into new VR designs, or they may be used to improve the SR driving characteristics of commercially available voltage sensing SR drivers.
    Type: Application
    Filed: September 8, 2011
    Publication date: March 15, 2012
    Inventors: Dong WANG, Yan-Fei LIU
  • Patent number: 8085083
    Abstract: Provided is a current-source gate driver for use with a switching device having a gate capacitance, including an input terminal for receiving a DC voltage; a first switch connected between the input terminal and an output terminal; a second switch connected between the output terminal and a circuit common; a series circuit comprising a first capacitor and an inductor, the series circuit connected between the input terminal and the output terminal; wherein the gate capacitance of the switching device is connected between the output terminal and the circuit common. The current-source gate driver improves efficiency of the power switching devices of a voltage regulator module or other switching converter.
    Type: Grant
    Filed: February 23, 2009
    Date of Patent: December 27, 2011
    Assignee: Queen's University at Kingston
    Inventors: Zhiliang Zhang, Yan-Fei Liu
  • Patent number: 8054058
    Abstract: The invention relates to a control method and a controller for a DC-DC converter, such as a synchronous Buck converter, which exploits the principle of capacitor charge balance to allow the converter to recover from a positive and/or negative load current step in the shortest achievable time, with the lowest possible voltage undershoot/overshoot. The control method may be implemented by either an analog or a digital circuit. The controller may be integrated with existing controller schemes (such as voltage-mode controllers) to provide superior dynamic performance during large-signal transient conditions while providing stable operation during steady state conditions.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: November 8, 2011
    Assignee: Queen's Univeristy at Kingston
    Inventors: Yan-Fei Liu, Eric Meyer
  • Publication number: 20110101951
    Abstract: non-isolated full bridge (FB) converters have self-driven synchronous rectifier (SR) MOSFETs in the current doubler rectifier (CDR). The gate terminals of the SR MOSFETs are connected to the bridge leg midpoints of the FB converter. The primary side of the FB converter shares the same ground of the secondary side, which provides the gate drive path for the SRs. The asymmetrical control featuring zero-voltage-switching (ZVS) capability is applied to the two bridge legs of the FB converter respectively. This creates the right gate drive voltage waveforms for the SRs. The energy of the leakage inductance of the transformer is used to achieve SR gate energy recovery. High gate drive voltages can be used to reduce the on-resistance of SRs and the conduction loss. In this way, no additional gate driver circuitry is needed for the SRs compared to the conventional external drive circuitry for SRs. In this invention, the above features provide high conversion efficiency with high switching frequency.
    Type: Application
    Filed: October 30, 2009
    Publication date: May 5, 2011
    Inventors: Zhiliang Zhang, Yan-Fei Liu
  • Patent number: 7936088
    Abstract: Distributed power supply arrangements and related methods are disclosed. Voltage is sensed at least one sense point in a power plane of a power distribution network. The power plane includes distributed source points and load points through which a plurality of power sources supply power to a plurality of loads. Currents supplied to the power plane by the power sources are regulated based on the voltage sensed at each of the at least one sense point.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: May 3, 2011
    Assignee: Power Integrations, Inc.
    Inventors: Raymond K. Orr, Yan-Fei Liu
  • Publication number: 20100038967
    Abstract: Distributed power supply arrangements and related methods are disclosed. Voltage is sensed at least one sense point in a power plane of a power distribution network. The power plane includes distributed source points and load points through which a plurality of power sources supply power to a plurality of loads. Currents supplied to the power plane by the power sources are regulated based on the voltage sensed at each of the at least one sense point.
    Type: Application
    Filed: October 19, 2009
    Publication date: February 18, 2010
    Inventors: Raymond K. Orr, Yan-Fei Liu