Patents Examined by Bao Q. Vu
  • Patent number: 8687390
    Abstract: An active clamp DC-DC converter includes a transformer having a primary coil and a secondary coil, a main switching device connected in series to the primary coil of the transformer so that the main switching device and the primary coil are connected in parallel to a DC power source, a reset capacitor, a reset switching device connected in series to the reset capacitor so that the reset switching device and the reset capacitor are connected in parallel to the primary coil of the transformer, a rectifying circuit connected to the secondary coil of the transformer, a smoothing circuit connected to the rectifying circuit, and a control circuit adjusting a dead time that elapses from the time when the reset switching device is turned off until the time when the main switching device is turned on, based on a voltage across the main switching device.
    Type: Grant
    Filed: July 28, 2011
    Date of Patent: April 1, 2014
    Assignee: Kabushiki Kaisha Toyota Jidoshokki
    Inventors: Yasuhiro Koike, Sergey Moiseev, Masanori Tsuzaka
  • Patent number: 8686705
    Abstract: A current mode synchronous rectification direct current (DC)/DC converter according to the present invention includes: a soft start function unit (in FIG. 1, a reference voltage generation unit (104) enabling a reference voltage REF to slowly increase while starting), for inhibiting a target value of an output voltage VO to be lower than that at a normal action while starting; and an output stabilization function unit (in FIG. 1, a frequency variable type oscillator (110A) generating a clock signal CLK and a slope voltage SLOPE through an oscillation frequency corresponding to a reference voltage REF), for performing at least one of waiting for start of a switching action and reduction of a drive frequency while starting.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: April 1, 2014
    Assignee: Rohm Co., Ltd.
    Inventors: Haruo Yamakoshi, Hirotaka Nakabayashi
  • Patent number: 8687383
    Abstract: An inverter and an active power filter system have been disclosed in the invention, so that the application range of the inverter under the occasions of different capacitor requirement can be widened, the cost can be decreased, and the efficiency can be improved. The technical scheme is: an auxiliary capacitor module can be added on the traditional inverter structure and connected in parallel selectively with the capacitor in the inverter. In a system without connecting an external auxiliary capacitor module, the value of capacitance can be designed to be smaller to satisfy the application under normal occasions. If the device operates under the occasions having large harmonic current or having large neutral line current, the ripple current on the capacitor will be larger so that large capacitance will be required to satisfy the life requirement, therefore, the problem can be solved by a method of installing an auxiliary capacitor module.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: April 1, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Bin Wang, Shouyan Wang, Xibing Ding, Hongyang Wu, Shaohua Chen
  • Patent number: 8680711
    Abstract: A switching power source apparatus includes a first arm including first and second switching elements, a second arm including third and fourth switching elements, a series circuit connected between a connection point of the first and second switching elements and a connection point of the third and fourth switching elements and including a capacitor and a primary winding, a rectifying-smoothing circuit that rectifies and smoothes a voltage of a secondary winding and provides an output voltage, a reactor connected to a connection point of the first and second switching elements and a DC input end, and a controller that turns on/off the first and second switching elements alternately and the third and fourth switching elements alternately and synchronizes the first and third switching elements with each other and the second and fourth switching elements with each other.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: March 25, 2014
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Akiteru Chiba
  • Patent number: 8680701
    Abstract: A circuit for regulating a DC voltage is provided. The circuit includes: a controllable switch system, a resistor, a first control circuit and a second control circuit. The controllable switch system includes a first terminal, a second terminal, a first control terminal, and a second control terminal. The controllable switch system is configured to establish an electrical connection between the first terminal and the second terminal, if a first control signal applied to the first control terminal satisfies a first criterion or if a second control signal applied to the second control terminal satisfies a second criterion; A method for regulating a DC voltage and an AC-to-AC-converter are described.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: March 25, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Rodney Jones
  • Patent number: 8669751
    Abstract: A controller for regulating an output of a power supply includes a logic block and an oscillator. The logic block generates the drive signal to control switching of a power switch in response to a clock signal. The clock signal has a frequency that decreases responsive to a time period of the drive signal, where a decrease in the time period of the drive signal represents an increase in an input voltage of the power supply. The oscillator is coupled to generate the clock signal in response to a waveform having an amplitude swing. The oscillator alters the waveform in response to the time period of the drive signal.
    Type: Grant
    Filed: June 14, 2012
    Date of Patent: March 11, 2014
    Assignee: Power Integrations, Inc.
    Inventors: Balu Balakrishnan, Alex B. Djenguerian, Leif Lund
  • Patent number: 8670260
    Abstract: A multiple inverter and an active power filter system are disclosed in the invention, said multiple inverter can decrease the volume and harmonics, increase the efficiency and decrease the cost, and can be applied to various occasions. The technical scheme is: the filter assembly in the multiple inverter is installed at the output inductor of the multiple inverter for filtering the harmonics.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: March 11, 2014
    Assignee: Delta Electronics (Shanghai) Co., Ltd.
    Inventors: Bin Wang, Hongyang Wu, Jian Jiang, Jingtao Tan, Yaping Yang
  • Patent number: 8665614
    Abstract: A control device for controlling a switching power supply adapted to convert an input voltage into an output voltage according to a switching rate of a switching element. The control device includes first control means for switching the switching element in a first working mode at a constant frequency and second control means for switching the switching element in a second working mode at a variable frequency, under a maximum frequency, in response to the detection of a predefined operative condition of the switching power supply. The control device further includes means for selecting the first working mode or the second working mode.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: March 4, 2014
    Assignee: STMicroelectronics S.r.l.
    Inventors: Giovanni Lombardo, Claudio Adragna, Salvatore Tumminaro
  • Patent number: 8665616
    Abstract: The present invention relates to a near zero current-ripple inversion circuit including top and bottom cells, a transformer (T1) comprising primary windings (P1, P2) and a secondary winding (S1), and at least one middle cell connected in series between the top and bottom cells. The top cell comprises two capacitors (C1, C2) and a switch (Q1) each connecting to the middle cell, and an inductor (Lr1) and the primary winding (P1) connected in series between the capacitor (C1) and switch (Q1), wherein the switch (Q1) is connected to the capacitors (C1, C2) respectively. The bottom cell comprises a capacitor (C3) and a switch (Q2) each connecting to the middle cell, and an inductor (Lr2) and the primary winding (P2) connected in series between the capacitor (C3) and switch (Q2), wherein the primary winding (P2) is connected to the middle cell, and the capacitor (C3) and switch (Q2) are connected.
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: March 4, 2014
    Assignee: National Taiwan University of Science and Technology
    Inventors: Ching-Shan Leu, Pin-Yu Huang
  • Patent number: 8665020
    Abstract: A differential amplifier circuit including: a differential input stage including a pair of differential MOS transistors, a pair of load elements, and a first constant-current source; an output stage including an output MOS transistor and a second constant-current source; a constant-current MOS transistor provided in parallel to one of the first and second constant-current sources; and a boost current controlling MOS transistor in which a potential of a connection node of the output MOS transistor and the second constant-current source is applied to a gate terminal thereof; wherein the boost current controlling MOS transistor is turned on when a voltage inputted to a gate terminal of one of the pair of differential MOS transistors changes, and a current of the constant-current MOS transistor is added to one of the first and second constant-current sources and is allowed to flow.
    Type: Grant
    Filed: July 1, 2011
    Date of Patent: March 4, 2014
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Kohei Sakurai, Akihiro Terada, Yoichi Takano
  • Patent number: 8659916
    Abstract: A control circuit for a resonant power converter and a control method thereof are disclosed. The control circuit comprises a first transistor and a second transistor switching a transformer through a resonant tank. A controller receives a feedback signal for generating a first switching signal and a second switching signal coupled to drive the first transistor and the second transistor respectively. The feedback signal is correlated to an output of the resonant power converter. A diode is coupled to the second transistor for detecting the state of the second transistor for the controller. The first switching signal and the second switching signal are modulated to achieve a zero voltage switching (ZVS) for the second transistor.
    Type: Grant
    Filed: May 23, 2012
    Date of Patent: February 25, 2014
    Assignee: System General Corp.
    Inventors: Ta-Yung Yang, Tien-Chi Lin
  • Patent number: 8659272
    Abstract: To provide a DC/DC converter capable of down-sizing magnetic components and varying boosting and bucking ratios, and a bidirectional boosting-bucking operations, a bidirectional boosting-bucking magnetic-field cancellation type of DC/DC converter (10) is provided which includes: a first voltage side port (P1), a second voltage side port (P2); a common reference terminal (CP), a smoothing capacitor (C1), four switching elements (SW1, SW2, SW3, SW4), an inductors (L1, L2), a magnetic-field cancellation type transformer T including a primary winding (L3) and a secondary winging (L4), four switching elements (SW5, SW6, SW7, SW8), and a smoothing capacitor (C2).
    Type: Grant
    Filed: August 3, 2010
    Date of Patent: February 25, 2014
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yasuto Watanabe, Mitsuaki Hirakawa
  • Patent number: 8659915
    Abstract: A valley-detection device for quasi-resonance switching and a method using the same is disclosed, which uses first and second capacitors to connect with a comparator, and the comparator connects with an NMOSFET connecting to a transformer. When the NMOSFET is turned off, the energy stored in the transformer is discharged and a resonant signal across the source and the drain is generated, and a first constant current charges the first capacitor at a start time point of the resonant signal until a voltage of the resonant signal first reaches to a crossing voltage. Then, a second constant current charges the second capacitor when the voltage of the resonant signal equals to the crossing voltage while the voltage of the resonant signal varies from high to low. Finally, the comparator turns on the NMOSFET when a voltage of the second capacitor equals to a voltage of the first capacitor.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: February 25, 2014
    Assignee: SYNC Power Corp.
    Inventor: Cheng-Wen Tsui
  • Patent number: 8659277
    Abstract: A current providing method utilized to a power supplying circuit, which provides an output current to a loading. The current providing method comprising: detecting if a current value of the output current is larger than a threshold current value; computing a number that the current value of the output current is larger than the threshold current value; determining if the number is larger or equal to a predetermined number; and controlling the power supplying circuit to decrease the output current to a predetermined current value if the number is larger or equal to the predetermined number.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: February 25, 2014
    Assignee: Realtek Semiconductor Corp.
    Inventor: Shih-Chieh Chen
  • Patent number: 8654546
    Abstract: A control circuit of a resonant power converter is disclosed. The control circuit comprises a first transistor and a second transistor for switching a transformer and a resonant tank comprising a capacitor and an inductor. A controller is configured to receive a feedback signal correlated to the output of the power converter for generating a first switching signal and a second switching signal to drive the first transistor and the second transistor, respectively. A diode coupled to the first transistor and the resonant tank for detecting the state of the first transistor and generating a detection signal for the controller. The detection signal indicates if the transistors are in a zero voltage switching (ZVS) state. If the transistors are not in the ZVS state, the switching frequency of the transistors will be increased.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 18, 2014
    Assignee: System General Corp.
    Inventors: Tien-Chi Lin, Hang-Seok Choi, Ta-Yung Yang
  • Patent number: 8653801
    Abstract: A boost circuit is used for power factor correction (PFC). In a low power application, transition mode control is utilized. However, switching frequency varies with different input voltages, and over a wide input voltage range, the switching frequency can become too high to be practical. To address this issue, a boost circuit is provided whose effective inductance changes as a function of input voltage. By changing the inductance, control is exercised over switching frequency.
    Type: Grant
    Filed: April 5, 2013
    Date of Patent: February 18, 2014
    Assignee: STMicroelectronics, Inc.
    Inventors: Jianwen Shao, Thomas L. Hopkins
  • Patent number: 8649188
    Abstract: A power generator includes one or more full bridge inverter modules coupled to a semiconductor opening switch (SOS) through an inductive resonant branch. Each module includes a plurality of switches that are switched in a fashion causing the one or more full bridge inverter modules to drive the semiconductor opening switch SOS through the resonant circuit to generate pulses to a load connected in parallel with the SOS.
    Type: Grant
    Filed: October 31, 2011
    Date of Patent: February 11, 2014
    Assignee: General Electric Company
    Inventors: Fengfeng Tao, Seyed Gholamali Saddoughi, John Thomas Herbon
  • Patent number: 8648587
    Abstract: The invention relates to the arrangement of a stepping switch on a control transformer, wherein either only the mechanical contact system (8) of the stepping switch or also its load changeover switch (7) is or are arranged within the tank (1) of the transformer, under the transformer cover (4) and above the iron yoke (3).
    Type: Grant
    Filed: May 8, 2010
    Date of Patent: February 11, 2014
    Assignee: Maschinenfabrik Reinhausen GmbH
    Inventors: Oliver Brueckl, Dieter Dohnal
  • Patent number: 8649187
    Abstract: A two-level two-terminal modular multilevel converter subsystem. The subsystem includes a first capacitor and a second capacitor. The modular multilevel converter subsystem is configured to selectively place the first capacitor in series with the second capacitor. The modular multilevel converter subsystem is also configured to selectively place the first capacitor in parallel with the second capacitor relative to first and second output terminals of the modular multilevel converter subsystem.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: February 11, 2014
    Assignee: Curtiss-Wright Electro-Mechanical Corporation
    Inventors: Marc Francis Aiello, Dustin Matthew Kramer, Kenneth Stephen Berton
  • Patent number: 8648582
    Abstract: The present invention provides a programmable low dropout linear regulator using a reference voltage to convert an input voltage into a regulated voltage according to a control signal. The programmable low dropout linear regulator includes an operational amplifier having a negative input coupled to receive the reference voltage, a first transistor having a gate coupled to an output terminal of the operational amplifier and a first source/drain coupled to an output terminal of the regulated voltage, a first impedance coupled between a positive input of the operational amplifier and the output terminal of the regulated voltage, and a second impedance coupled between the positive input of the operational amplifier and a ground. The second impedance includes a second transistor having a gate coupled to receive the control signal.
    Type: Grant
    Filed: December 27, 2010
    Date of Patent: February 11, 2014
    Assignee: National Chung Cheng University
    Inventors: Chung-Hsun Huang, Ke-Ming Su