Patents by Inventor Li-Zhi Xu

Li-Zhi Xu 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: 10111284
    Abstract: A light driving circuit includes a first and second illuminant unit, a power conversion unit, a first and second switching unit, and a first control unit. The power conversion unit receives an input voltage and converts the input voltage into an output voltage. The first switching unit is coupled to the first illuminant unit. When the first switching unit is turned on, the first illuminant unit is driven by the output voltage to emit light and generate a first output current. The second switching unit is coupled to the second illuminant unit. When the second switching unit is turned on, the second illuminant unit is driven by the output voltage to emit light and generate a second output current. The first control unit controls the first switching unit and the second switching unit to be turned on/off according to the first output current and the second current, respectively.
    Type: Grant
    Filed: September 3, 2014
    Date of Patent: October 23, 2018
    Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Wei-Qiang Zhang, Li-Zhi Xu, Zhi-Hui Ding
  • Patent number: 9847707
    Abstract: A converter includes a first bridge arm and a voltage clamping unit. The first bridge arm includes a first switching unit. The voltage clamping unit is coupled to the first bridge arm, and includes a first charging branch and a second charging branch. The first charging branch is configured to have a first resonant frequency, to absorb a first spike of the first switching unit. The second charging branch is configured to have a second resonant frequency to absorb a second spike of the first switching unit.
    Type: Grant
    Filed: July 17, 2016
    Date of Patent: December 19, 2017
    Assignee: DELTA ELECTRONICS, INC.
    Inventors: Wei-Yi Feng, Li-Zhi Xu, Wei-Qiang Zhang, Hong-Yang Wu
  • Publication number: 20170054359
    Abstract: A converter includes a first bridge arm and a voltage clamping unit. The first bridge arm includes a first switching unit. The voltage clamping unit is coupled to the first bridge arm, and includes a first charging branch and a second charging branch. The first charging branch is configured to have a first resonant frequency, to absorb a first spike of the first switching unit. The second charging branch is configured to have a second resonant frequency to absorb a second spike of the first switching unit.
    Type: Application
    Filed: July 17, 2016
    Publication date: February 23, 2017
    Inventors: Wei-Yi FENG, Li-Zhi XU, Wei-Qiang ZHANG, Hong-Yang WU
  • Patent number: 9343975
    Abstract: A power converter includes a primary side compensation capacitor, a transformer and a secondary side compensation capacitor. The primary side compensation capacitor receives a first AC voltage from a first switch circuit. The transformer receives the first AC voltage to generate a second AC voltage. The secondary side compensation capacitor transfers the second AC voltage to a second switch circuit to generate a DC output voltage. The operating frequency of the first switch circuit is set within the 0.8*fa to 1.2*fb, and fb is at most 1.5 times of fa. The primary side compensation capacitor and a primary side leakage inductance of the transformer correspond to a first resonant frequency, the secondary side compensation capacitor and a secondary side leakage inductance of the transformer correspond to a second resonant frequency, fa and fb are the lower one and the higher one of the first and second resonant frequency respectively.
    Type: Grant
    Filed: April 4, 2014
    Date of Patent: May 17, 2016
    Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Chao Yan, Wei-Qiang Zhang, Li-Zhi Xu, Xin-Lei Li
  • Patent number: 9343970
    Abstract: A converter and method for reducing voltage of node thereof are disclosed herein. The converter includes a first transmitting circuit and a second transmitting circuit. The first transmitting circuit is configured to receive a first AC voltage. The second transmitting circuit is electrically coupled to the first transmitting circuit and the second transmitting circuit is configured to transmit a second AC voltage according to the first AC voltage. One of the first transmitting circuit and the second transmitting circuit includes at least one divider unit and the other one of the first transmitting circuit and the second transmitting circuit includes at least two divider units. Each of the divider units includes an inductor network and a capacitor network coupled in series. The inductor network and the capacitor network of the adjacent divider units are coupled in series alternately.
    Type: Grant
    Filed: May 6, 2014
    Date of Patent: May 17, 2016
    Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Chao Yan, Wei-Qiang Zhang, Li-Zhi Xu, Xin-Lei Li
  • Publication number: 20150173143
    Abstract: A light driving circuit includes a first and second illuminant unit, a power conversion unit, a first and second switching unit, and a first control unit. The power conversion unit receives an input voltage and converts the input voltage into an output voltage. The first switching unit is coupled to the first illuminant unit. When the first switching unit is turned on, the first illuminant unit is driven by the output voltage to emit light and generate a first output current. The second switching unit is coupled to the second illuminant unit. When the second switching unit is turned on, the second illuminant unit is driven by the output voltage to emit light and generate a second output current. The first control unit controls the first switching unit and the second switching unit to be turned on/off according to the first output current and the second current, respectively.
    Type: Application
    Filed: September 3, 2014
    Publication date: June 18, 2015
    Inventors: Wei-Qiang ZHANG, Li-Zhi XU, Zhi-Hui DING
  • Publication number: 20150049516
    Abstract: A power converter includes a primary side compensation capacitor, a transformer and a secondary side compensation capacitor. The primary side compensation capacitor receives a first AC voltage from a first switch circuit. The transformer receives the first AC voltage to generate a second AC voltage. The secondary side compensation capacitor transfers the second AC voltage to a second switch circuit to generate a DC output voltage. The operating frequency of the first switch circuit is set within the 0.8*fa to 1.2*fb, and fb is at most 1.5 times of fa. The primary side compensation capacitor and a primary side leakage inductance of the transformer correspond to a first resonant frequency, the secondary side compensation capacitor and a secondary side leakage inductance of the transformer correspond to a second resonant frequency, fa and fb are the lower one and the higher one of the first and second resonant frequency respectively.
    Type: Application
    Filed: April 4, 2014
    Publication date: February 19, 2015
    Applicant: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Chao YAN, Wei-Qiang ZHANG, Li-Zhi XU, Xin-Lei LI
  • Publication number: 20150049517
    Abstract: A converter and method for reducing voltage of node thereof are disclosed herein. The converter includes a first transmitting circuit and a second transmitting circuit. The first transmitting circuit is configured to receive a first AC voltage. The second transmitting circuit is electrically coupled to the first transmitting circuit and the second transmitting circuit is configured to transmit a second AC voltage according to the first AC voltage. One of the first transmitting circuit and the second transmitting circuit includes at least one divider unit and the other one of the first transmitting circuit and the second transmitting circuit includes at least two divider units. Each of the divider units includes an inductor network and a capacitor network coupled in series. The inductor network and the capacitor network of the adjacent divider units are coupled in series alternatively.
    Type: Application
    Filed: May 6, 2014
    Publication date: February 19, 2015
    Applicant: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Chao YAN, Wei-Qiang ZHANG, Li-Zhi XU, Xin-Lei LI
  • Patent number: 8810143
    Abstract: A control system includes a detection circuit, a control circuit, and a dummy load system. The detection circuit is operable to detect a voltage level change of a direct-current voltage and output an activating signal when detecting the voltage level change of the DC voltage. The control circuit is operable to receive the activating signal. The dummy load system is electrically connected to the control circuit, and the control circuit controls the dummy load system by generating a turn-on signal in response to receiving the activating signal. A dimmer system and a control method thereof are further disclosed herein.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: August 19, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Wei-Qiang Zhang, Li-Zhi Xu, Qi Zhang
  • Patent number: 8749171
    Abstract: A lighting apparatus includes a lighting unit, a converting circuit, a sensing circuit, and a current control circuit. The lighting unit includes at least one light emitting diode and a switching device connected with each other in series. The converting circuit has an output end electrically connected to the lighting unit for driving it. The sensing circuit includes a sensing element capable of indirectly detecting the current flowing through the light emitting diode and outputting a feedback signal. The current control circuit receives a reference current, the feedback signal and a dimming command, and sends a dimming control signal to the lighting unit and a current control signal to the converting circuit, capable of controlling the amplitude of the current flowing through the light emitting diode.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: June 10, 2014
    Assignee: Delta Electronics Inc.
    Inventors: Wei-Qiang Zhang, Li-Zhi Xu, Qi Zhang, Jian-Ping Ying
  • Patent number: 8729818
    Abstract: The invention discloses a driving circuit structure for driving light-emitting loads. The driving circuit structure may include a power supplying device, a signal processing device and an impedance balancing device and a dimming control unit. The power supplying device is used for supplying an alternating current power supply. The signal processing device is used for converting the alternating current power supply into a direct current power supply, so as to drive the light-emitting loads. The impedance balancing device is used for balancing an alternating current magnitude of the alternating current power supply, so as to stabilize a direct current magnitude of the direct current power supply for driving the light-emitting loads. The dimming control unit is capable of controlling output luminance of the light-emitting loads.
    Type: Grant
    Filed: September 23, 2011
    Date of Patent: May 20, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Wei-Qiang Zhang, Li-Zhi Xu, Jian-Ping Ying
  • Patent number: 8710758
    Abstract: A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.
    Type: Grant
    Filed: September 22, 2011
    Date of Patent: April 29, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Li-Zhi Xu, Wei-Qiang Zhang, Qi Zhang
  • Publication number: 20120319608
    Abstract: A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.
    Type: Application
    Filed: September 22, 2011
    Publication date: December 20, 2012
    Applicant: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Li-Zhi XU, Wei-Qiang ZHANG, Qi ZHANG
  • Publication number: 20120320646
    Abstract: A control system includes a detection circuit, a control circuit, and a dummy load system. The detection circuit is operable to detect a voltage level change of a direct-current voltage and output an activating signal when detecting the voltage level change of the DC voltage. The control circuit is operable to receive the activating signal. The dummy load system is electrically connected to the control circuit, and the control circuit controls the dummy load system by generating a turn-on signal in response to receiving the activating signal. A dimmer system and a control method thereof are further disclosed in herein.
    Type: Application
    Filed: September 20, 2011
    Publication date: December 20, 2012
    Applicant: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Wei-Qiang ZHANG, Li-Zhi XU, Qi ZHANG
  • Publication number: 20120262081
    Abstract: The invention discloses a driving circuit structure for driving light-emitting loads. The driving circuit structure may include a power supplying device, a signal processing device and an impedance balancing device and a dimming control unit. The power supplying device is used for supplying an alternating current power supply. The signal processing device is used for converting the alternating current power supply into a direct current power supply, so as to drive the light-emitting loads. The impedance balancing device is used for balancing an alternating current magnitude of the alternating current power supply, so as to stabilize a direct current magnitude of the direct current power supply for driving the light-emitting loads. The dimming control unit is capable of controlling output luminance of the light-emitting loads.
    Type: Application
    Filed: September 23, 2011
    Publication date: October 18, 2012
    Applicant: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Wei-Qiang ZHANG, Li-Zhi XU, Jian-Ping YING
  • Publication number: 20120074866
    Abstract: A lighting apparatus includes a lighting unit, a converting circuit, a sensing circuit, and a current control circuit. The lighting unit includes at least one light emitting diode and a switching device connected with each other in series. The converting circuit has an output end electrically connected to the lighting unit for driving it. The sensing circuit includes a sensing element capable of indirectly detecting the current flowing through the light emitting diode and outputting a feedback signal. The current control circuit receives a reference current, the feedback signal and a dimming command, and sends a dimming control signal to the lighting unit and a current control signal to the converting circuit, capable of controlling the amplitude of the current flowing through the light emitting diode.
    Type: Application
    Filed: March 11, 2011
    Publication date: March 29, 2012
    Inventors: Wei-Qiang ZHANG, Li-Zhi Xu, Qi Zhang, Jian-Ping Ying