Patents by Inventor Daofei Xu

Daofei 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: 12289055
    Abstract: A flyback circuit and a control method of a clamping switch of the flyback circuit are provided. The flyback circuit includes a transformer, a main switch, a clamping capacitor, a clamping switch, and a secondary rectifier unit. The transformer includes primary and secondary windings with a turns ratio of K. The main switch and the primary winding are connected in series to receive an input voltage. The clamping switch and the clamping capacitor are connected in series and then connected to the primary winding in parallel. The secondary rectifier unit and the secondary winding are connected in series to provide an output voltage to a load. The control method includes: when a product of K and the output voltage is greater than or equal to the input voltage, controlling the clamping switch to turn on M times during N consecutive switching cycles of the main switch, where I?M<N.
    Type: Grant
    Filed: September 19, 2022
    Date of Patent: April 29, 2025
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Qiangqiang Wang, Daofei Xu, Jinfa Zhang
  • Publication number: 20250096665
    Abstract: The present disclosure provides a method for controlling a power adapter and a power adapter, and relates to the field of power technologies. The method includes: obtaining a real-time value of a bus voltage of the power adapter; matching the real-time value of the bus voltage with N control voltage intervals V1 to VN to obtain a real-time control voltage interval that matches the real-time value of the bus voltage, wherein N?2, the N control voltage intervals are continuous and incremental from V1 to VN, and the N control voltage intervals V1 to VN correspond to N different output power control values P1 to PN; and adjusting, according to the real-time control voltage interval, an output power command value of the power adapter to an output power control value corresponding to the real-time control voltage interval.
    Type: Application
    Filed: August 27, 2024
    Publication date: March 20, 2025
    Applicant: Delta Electronics (Shanghai) CO., LTD.
    Inventors: Kehua MA, Daofei XU, Haitao ZHANG
  • Publication number: 20250062605
    Abstract: The present disclosure relates to a hot-plug protection method and a power supply device. The method includes, when the connection status between the power supply device and the to-be-charged device is detected as disconnected through the detection pin, turning off a switch assembly within a first time period, where the switch assembly is connected in series between the voltage converter of the power supply device and the connection port, and maintaining an output voltage of the voltage converter at a first level within a second time period, the first time period being shorter than the second time period.
    Type: Application
    Filed: August 15, 2024
    Publication date: February 20, 2025
    Inventors: Yuxin ZHANG, Kehua MA, Daofei XU, Haitao ZHANG, Bingtao HU
  • Publication number: 20240333170
    Abstract: The invention discloses a power conversion circuit and a power supply device. The power conversion circuit is applied to a power supply device, comprising: an AC/DC conversion circuit, wherein a DC side of the AC/DC conversion circuit has a first reference potential point; a first common-mode inductor; a DC/DC conversion circuit including a primary circuit having a second reference potential point, a secondary circuit and a transformer; wherein a first terminal of the first common-mode inductor is connected to the DC side of the AC/DC conversion circuit, and a second terminal of the first common-mode inductor is connected to the primary circuit of the DC/DC conversion circuit; the first reference potential point or the second reference potential point is connected to an electric field shield.
    Type: Application
    Filed: March 21, 2024
    Publication date: October 3, 2024
    Inventors: Qi FU, Daofei XU, Shengnan XIE, Jinfa ZHANG
  • Publication number: 20240266964
    Abstract: A flyback power converter includes a transformer, a voltage clamping circuit, a main switch element and a control circuit. The voltage clamping circuit includes a first capacitor and a clamping switch element. The first capacitor is electrically connected with a primary winding of the transformer. The clamping switch element is electrically connected between the capacitor and the primary winding. The control circuit detects a capacitor voltage of the first capacitor and a current flowing through the clamping switch element. If the capacitor voltage is greater than a reference voltage, the clamping switch element is turned on. If the capacitor voltage is not greater than the reference voltage and the current flowing through the clamping switch element is lower than a reference current value, the clamping switch element is turned off.
    Type: Application
    Filed: February 1, 2024
    Publication date: August 8, 2024
    Inventors: Kehua Ma, Haitao Zhang, Daofei Xu
  • Patent number: 12027299
    Abstract: Present disclosure provides a winding assembly and a magnetic element. The winding assembly includes a circuit board with a central hole and a first winding wound around the central hole in the circuit board; the first winding includes N turns of coil on at least two wiring layers; a second end of at least one turn of coil on a first wiring layers is connected to a first end of next turn of coil at corresponding position on a second wiring layer of the circuit board. The magnetic element includes a magnetic core and a winding assembly sleeved on a magnetic leg.
    Type: Grant
    Filed: April 9, 2021
    Date of Patent: July 2, 2024
    Assignee: Delta Electronics (Shanghai) CO., LTD
    Inventors: Qi Fu, Haibin Song, Daofei Xu, Zengyi Lu, Jinfa Zhang
  • Publication number: 20240195318
    Abstract: A switching power converter and a control method thereof are provided. First, a switching power converter is provided. The switching power converter includes a main switch and an auxiliary circuit electrically connected in parallel to the main switch, and the auxiliary circuit includes an auxiliary switch and an auxiliary capacitor electrically connected in series. Afterwards, a load state of the switching power converter is detected. When the load state of the switching power converter is light, the auxiliary switch is controlled to turn off for maintaining a capacitance of a first equivalent capacitor between a drain and a source of the main switch at a low threshold. When the load state of the switching power converter is heavy, the auxiliary switch is controlled to turn on for maintaining the capacitance of the first equivalent capacitor at a high threshold.
    Type: Application
    Filed: December 7, 2023
    Publication date: June 13, 2024
    Inventors: Kehua Ma, Daofei Xu, Haitao Zhang
  • Publication number: 20240162825
    Abstract: A control method for a flyback power converter is provided. Firstly, a flyback power converter is provided. The flyback power converter includes a transformer, a leakage inductance energy recovery circuit and a control unit. Then, a delayed turn-off time period is defined by the control unit. Then, a detection signal related to a current flowing through the leakage inductance energy recovery circuit is detected. If the detection signal is greater than or equal to a first set value, a switch element of the leakage inductance energy recovery circuit is turned on. If the detection signal is lower than or equal to a second set value, the second switch element is turned off after the delayed turn-off time period.
    Type: Application
    Filed: October 18, 2023
    Publication date: May 16, 2024
    Inventors: Kehua Ma, Daofei Xu, Haitao Zhang
  • Publication number: 20240146172
    Abstract: A power adapter includes a transformer, an output terminal, a secondary side circuit and a secondary side controller including an operational amplifier. The secondary side circuit includes a first switch, a second switch and a sampling resistor. The first switch is connected with a secondary winding of the transformer and the second switch. The second switch is connected with the output terminal. The sampling resistor is connected between the secondary winding and the output terminal for acquiring a sampling voltage. The operational amplifier generates a voltage difference value according to the result of comparing a reference voltage value with a feedback voltage value. When the sampling voltage is lower than a first voltage level and the voltage difference value is greater than a second voltage level, the second switch is turned off under control of the secondary side controller.
    Type: Application
    Filed: September 7, 2023
    Publication date: May 2, 2024
    Inventors: Kehua Ma, Daofei Xu, Haitao Zhang
  • Patent number: 11973430
    Abstract: The application discloses a converter adaptable to a wide range output voltage and a control method thereof. The converter includes a PWM half-bridge circuit. The control method includes: causing the PWM half-bridge circuit to enter into a DCM by regulating a switching frequency; in each switching period, extending conduction time or turning on a corresponding synchronous rectifier once again for a predetermined time before the first power switch and the second power switch are turned on, to realize zero voltage switching (ZVS) of the first power switch and the second power switch. The application realizes ZVS of the primary power switches, thereby reducing loss.
    Type: Grant
    Filed: April 7, 2022
    Date of Patent: April 30, 2024
    Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Hairui Xu, Haibin Song, Daofei Xu, Jinfa Zhang
  • Publication number: 20240106253
    Abstract: The present disclosure provides a control method of a charging system. The control method includes: providing a charging chip, wherein the charging chip is configured to charge a chargeable device, and the charging chip performs a wake-up task with a wake-up period during a standby mode; performing a plurality of wake-up subtasks in the wake-up task; and according to the priority of each of the plurality of wake-up subtasks, setting a corresponding working cycle of each wake-up subtasks, wherein the charging chip performs each of the wake-up subtasks with the corresponding working cycle, and the wake-up subtasks with different priorities have different working cycles.
    Type: Application
    Filed: June 30, 2023
    Publication date: March 28, 2024
    Inventors: Bingtao Hu, Kehua Ma, Daofei Xu, Haitao Zhang
  • Patent number: 11824456
    Abstract: A hybrid flyback circuit is provided and includes an upper switch, a lower switch, a transformer, a resonant circuit, a current sampling circuit and a control unit. The control unit includes an output voltage feedback unit, a peak current comparison unit controlling the upper switch to turn off when a sampling voltage corresponding to the current sampling signal is equal to the first voltage feedback signal, a first dead time delay unit controlling the lower switch to turn on after a first dead time starting from the turn-off time of the upper switch, a negative peak current feedback unit for generating a second voltage feedback signal, a conduction control unit controlling the lower switch to turn off, and a second dead time delay unit controlling the upper switch to turn on after a second dead time starting from the turn-off time of the lower switch.
    Type: Grant
    Filed: January 11, 2022
    Date of Patent: November 21, 2023
    Assignee: DELTA ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Haibin Song, Hairui Xu, Fengkai Jiang, Daofei Xu, Jinfa Zhang
  • Publication number: 20230336086
    Abstract: A flyback circuit and a control method of a clamping switch of the flyback circuit are provided. The flyback circuit includes a transformer, a main switch, a clamping capacitor, a clamping switch, and a secondary rectifier unit. The transformer includes primary and secondary windings with a turns ratio of K. The main switch and the primary winding are connected in series to receive an input voltage. The clamping switch and the clamping capacitor are connected in series and then connected to the primary winding in parallel. The secondary rectifier unit and the secondary winding are connected in series to provide an output voltage to a load. The control method includes: when a product of K and the output voltage is greater than or equal to the input voltage, controlling the clamping switch to turn on M times during N consecutive switching cycles of the main switch, where 1=<M<N.
    Type: Application
    Filed: September 19, 2022
    Publication date: October 19, 2023
    Inventors: Qiangqiang Wang, Daofei Xu, Jinfa Zhang
  • Patent number: 11774516
    Abstract: The present application provides a detecting method of an operating state of a power supply and a detecting apparatus, where the power supply includes a primary circuit, a transformer and a secondary circuit. The secondary circuit includes a secondary current detecting unit, a temperature detecting unit and a secondary controlling unit. Firstly the secondary current detecting unit detects a current value of the secondary circuit, then the secondary controlling unit compares the current value of the secondary circuit with a preset current threshold. When the current value of the secondary circuit is less than or equal to the preset current threshold, the temperature detecting unit detects a temperature value of the power supply and the secondary controlling unit determines the operating state of the power supply according to the acquired temperature value of the power supply.
    Type: Grant
    Filed: April 22, 2022
    Date of Patent: October 3, 2023
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Yunfei Liu, Haibin Song, Daofei Xu, Jinfa Zhang
  • Patent number: 11777408
    Abstract: The invention discloses a converter adaptable to a wide range output voltage and a control method thereof. The converter comprises a PWM half-bridge circuit. The control method comprises the steps of: controlling the PWM half-bridge circuit to enter into a discontinuous conduction mode by regulating a switching frequency; when the PWM half-bridge circuit is operated in the discontinuous conduction mode, oscillation occurs among the output inductor, a magnetizing inductor of the transformer and a parasitic capacitor of the PWM half-bridge circuit, and when a center point voltage of the primary switching bridge arm reaches a valley or a peak, turning on the corresponding power switch. The invention reduces switching loss by controlling the corresponding power switch in the PWM half-bridge circuit to turn on when a voltage across the power switch is oscillated to valley.
    Type: Grant
    Filed: April 18, 2022
    Date of Patent: October 3, 2023
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Hairui Xu, Haibin Song, Daofei Xu, Jinfa Zhang
  • Patent number: 11737219
    Abstract: A power adapter includes a first output port, a second output port, a motherboard, a first flyback power module, a second flyback power module, a bus capacitor and an EMI module. The first flyback power module has a first circuit board and is electrically connected to the first output port. The second flyback power module has a second circuit board and is electrically connected to the second output port. The EMI module has a third circuit board and is arranged on the motherboard. The first circuit board and the second circuit board are arranged in parallel with each other, and are arranged substantially perpendicular to the motherboard on a first side of the motherboard.
    Type: Grant
    Filed: March 30, 2021
    Date of Patent: August 22, 2023
    Assignee: Delta Electronics (Shanghai) CO., LTD
    Inventors: Haibin Song, Jian Zhou, Daofei Xu, Jinfa Zhang
  • Patent number: 11711017
    Abstract: The present disclosure relates to an adapter. The adapter includes an input port, a first output port and a second output port, and the adapter further includes: a rectifier circuit having an input terminal being connected to the input port of the adapter; a bus capacitor connected to an output terminal of the rectifier circuit in parallel; a first flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the first output port; and a second flyback converter having an input terminal connected to the bus capacitor and an output terminal coupled to the second output port.
    Type: Grant
    Filed: January 26, 2021
    Date of Patent: July 25, 2023
    Assignee: Delta Electronics (Shanghai) CO., LTD
    Inventors: Jian Zhou, Haibin Song, Daofei Xu, Jinfa Zhang
  • Patent number: D997876
    Type: Grant
    Filed: February 4, 2021
    Date of Patent: September 5, 2023
    Assignee: Delta Electronics (Shanghai) CO., LTD
    Inventors: Haibin Song, Qi Fu, Daofei Xu, Jinfa Zhang
  • Patent number: D1005953
    Type: Grant
    Filed: February 4, 2021
    Date of Patent: November 28, 2023
    Assignee: Delta Electronics (Shanghai) CO., LTD
    Inventors: Haibin Song, Qi Fu, Daofei Xu, Jinfa Zhang
  • Patent number: RE50277
    Abstract: A flyback power converter includes a hybrid clamp circuit and a corresponding power management unit that substantially optimizes the performance of the flyback power converter in its entire line and load ranges. The clamp circuit, which is connected in parallel to a primary winding of the flyback transformer, includes a parallel combination of a capacitor and resistor that is connected in series with a parallel combination of a switch and a diode. By sensing the operating conditions, the power management circuit configures the clamp circuit either as a passive clamp or as an active clamp. In the passive-clamp configuration, the switch is kept turned off. In the active-clamp configuration, the switch operates with pulse-width modulation (PWM) which enables ZVS turn-on of the main switch.
    Type: Grant
    Filed: July 17, 2020
    Date of Patent: January 21, 2025
    Assignee: Delta Electronics, Inc.
    Inventors: Haibin Song, Laszlo Huber, Daofei Xu, Alpha Zhang, Milan M. Jovanovic, Chien-Chung Chang