For Flyback-type Converter Patents (Class 363/21.12)
  • Publication number: 20140112028
    Abstract: In various embodiments a method for determining a demagnetization zero current time, at which a transformer is substantially demagnetized, for a switched mode power supply comprising a transformer is provided, wherein the method may include: applying a first current through a winding of one side of the transformer; interrupting the current flow of the first current; measuring a time at which a voltage across a winding of another side of the transformer becomes substantially zero; and determining the demagnetization zero current time using the measured time.
    Type: Application
    Filed: October 24, 2012
    Publication date: April 24, 2014
    Applicant: INFINEON TECHNOLOGIES AG
    Inventors: Marc Fahlenkamp, Ordwin Haase
  • Patent number: 8699241
    Abstract: There is provided a switching mode power supply including: a direct current (DC)/DC converting unit converting a DC power level; an auxiliary power supply unit discharged in a no load mode in which a load is not connected to an output terminal of the DC/DC converting unit; and a controlling unit sensing a change in impedance according to whether or not the load is connected to the output terminal to thereby determine whether or not the switching mode power supply is in the no load mode, and driving a pulse width modulation integrated chip (PWM IC) when a voltage level of the auxiliary power supply unit is at a preset level or less in the no load mode.
    Type: Grant
    Filed: September 27, 2011
    Date of Patent: April 15, 2014
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventors: Byoung Woo Ryu, Young Woon Choi, Seong Wook Choi
  • Patent number: 8693222
    Abstract: A DC-DC converter includes a first winding of a first transformer to which direct current power is supplied, a switching element configured to be connected in series with the first winding of the first transformer, a first winding of a second transformer and a capacitor configured to be connected in series with each other and in parallel with the switching element, a second winding of the first transformer configured to be coupled with the first winding of the first transformer, output terminals configured to be connected to the second winding of the first transformer and to output direct current power, and a pair of second windings of the second transformer configured to be coupled with the first winding of the second transformer, the second windings of the second transformer being connected in parallel with each other with reverse polarity between the output terminals.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: April 8, 2014
    Assignee: Fujitsu Limited
    Inventors: Yu Yonezawa, Yoshiyasu Nakashima
  • Patent number: 8693223
    Abstract: A power converter includes an output unit, a first transformer, a switch unit, and a processing unit. The first transformer includes a primary winding and a secondary winding. The primary winding is coupled between an input voltage and a first node. The switch unit is coupled between the first node and a second node. The processing unit is coupled between the input voltage and the first node. When the switch unit is in an OFF state, the processing unit is used to receive a first sensing voltage and store a sensing power of the first sensing voltage through a first path, isolate the first sensing voltage from feeding in through a second path different from the first path simultaneously, and then release the stored sensing power through the second path. The first sensing voltage is generated as the switch unit switches from an ON state to the OFF state.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: April 8, 2014
    Assignee: FSP Technology Inc.
    Inventor: Cody Lin
  • Publication number: 20140092644
    Abstract: A switching power supply device includes a rectifying circuit configured to rectify an AC voltage and to output a rectified voltage, a smoothing capacitor configured to smooth the rectified voltage and to output a smoothed voltage, a first DC-DC converter configured to convert the smoothed voltage into an intermediate voltage and to output the intermediate voltage, and a second DC-DC converter configured to convert the intermediate voltage into an output voltage and to output the output voltage substantially free of ripple. The first DC-DC converter is configured to perform a step-up operation, a step-up/down operation, and a step-down operation according to the smoothed voltage, and to output the intermediate voltage including a ripple or the intermediate voltage substantially free of ripple.
    Type: Application
    Filed: September 27, 2013
    Publication date: April 3, 2014
    Applicant: Yokogawa Electric Corporation
    Inventor: Yasuyuki KAWASUMI
  • Publication number: 20140092642
    Abstract: The present invention includes: a converter configured to convert the direct-current voltage of the rectifier to another direct-current voltage and supply to a load; a peak hold unit configured to hold a peak value of a current detected by a current detecting unit configured to detect a current flowing in the switching element; an averaging unit configured to convert, to a current, an output of an n/2 output unit, and then integrate and output the converted current, the n/2 output unit configured to output n/2 (n is an integer of 1 or more) of the held peak value only in a regeneration current period of the reactor; a control unit configured to turn the switching element on and off based on an output signal of the averaging unit in such a way that an average current value of a current flowing in the reactor is equal to a predetermined value.
    Type: Application
    Filed: September 24, 2013
    Publication date: April 3, 2014
    Applicant: Sanken Electric Co., Ltd.
    Inventor: Mitsutomo YOSHINAGA
  • Publication number: 20140092643
    Abstract: An electronic converter may include transformer with a primary winding and a secondary winding, wherein the primary winding is coupled to an input for receiving a power signal, and wherein the secondary winding is coupled to an output including a positive terminal and a negative terminal for providing a power signal. The converter moreover may include an electronic switch arranged between the input and the primary winding, wherein the electronic switch is configured to control the current flow through the primary winding. Specifically, the converter may include a snubber circuit arranged between the secondary winding and the output.
    Type: Application
    Filed: September 27, 2013
    Publication date: April 3, 2014
    Applicant: OSRAM GmbH
    Inventor: Daniele Luccato
  • Patent number: 8687387
    Abstract: A frequency limitation method used in a quasi-resonant controlled switching regulator is disclosed. The switching frequency is limited by setting a minimum time period, such as a minimum switching period or a minimum OFF time period. The minimum time period is varying according to the difference between the minimum time period of the previous cycle and an offset value, so as to eliminate the audible noise caused by the frequency hopping when the minimum OFF time period is close to the valley of a quasi-resonant signal.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: April 1, 2014
    Assignee: Chengdu Monolithic Power Systems Co., Ltd.
    Inventors: Yike Li, Rui Wang, En Li
  • Patent number: 8687392
    Abstract: A power converter is provided that has an alternating-current (AC) to direct-current (DC) switched-mode power converter circuit that converts alternating-current power into direct-current power for powering an attached electronic device. Power can be conserved by automatically placing the power converter circuit in a low-power standby mode of operation whenever the electronic device is detached from the power converter. A monitoring circuit can be powered by a capacitor or other energy storage element while the power converter is operating in the standby mode. If the monitoring circuit detects an output voltage change that is indicative of attachment of the electronic device or if the storage element needs to be replenished, the monitoring circuit can place the power converter circuit in an active mode of operation.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: April 1, 2014
    Assignee: Apple Inc.
    Inventors: Nicholas A. Sims, Jeffrey Terlizzi
  • Patent number: 8686761
    Abstract: A gate driver of a switching element includes a first capacitor having a first end connected to a DC power source, a first switch having a first electrode connected to the first end of the first capacitor and a second electrode connected to a negative electrode of the DC power source, a second switch having a third electrode connected to the second electrode and the negative electrode of the DC power source and a fourth electrode connected to the first capacitor, a second capacitor connected in parallel with the third and fourth electrodes of the second switch and having a first end connected to the DC power source, and a negative voltage controller connecting the gate of the switching element to the second end of the first capacitor and a second end of the second capacitor when the switching element is turned off.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: April 1, 2014
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Keiichiro Ozawa
  • Publication number: 20140085941
    Abstract: A power converter includes a transformer with a primary and a secondary winding and a switch. A controller of the power converter at the primary winding side of the transformer generates a control signal to turn on or turn off the switch, the switch being turned on responsive to the control signal being in a first state and the switch being turned off responsive to the control signal being in a second state. The controller determines current through the primary winding generated while the switch is turned on and indirectly detects an input voltage to the power converter based on the current through the primary winding generated while the switch is turned on. The controller in turn may detect conditions such as a loss of power or brown out at the input of the power converter based on the indirectly detected input voltage.
    Type: Application
    Filed: September 23, 2013
    Publication date: March 27, 2014
    Applicant: iWatt Inc.
    Inventors: Yong Li, Hien Huu Bui, David Nguyen, Fuqiang Shi
  • Publication number: 20140085940
    Abstract: A controller of a switching power converter includes a voltage protection circuit that generates a modified supply voltage that does not exceed a predetermined threshold voltage to power one or more components of the controller.
    Type: Application
    Filed: September 19, 2013
    Publication date: March 27, 2014
    Applicant: iWatt Inc.
    Inventors: Andrew Kwok-Cheung Lee, Jiang Chen, Yong Li
  • Patent number: 8674627
    Abstract: An isolated flyback converter for an LED driver includes a snubber circuit unit connected to the primary side of a transformer; and a snubber voltage detection unit which detects a snubber voltage of the snubber circuit unit and generates a reference voltage proportional to the detected snubber voltage. Further, the isolated flyback converter includes a switching unit with a source terminal and a drain terminal, and may be turned on or off in response to an arbitrary logic signal. Furthermore, the isolated flyback converter includes a control unit which compares a voltage supplied through the switching current sensing resistor with the reference voltage, and supplies a logic signal at relatively high level or relatively low level to the switching unit to control the switching unit such that a secondary-side current of the transformer is maintained relatively constant.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: March 18, 2014
    Assignee: Dongbu Hitek Co., Ltd.
    Inventors: Jong Tae Hwang, Moonsang Jung, Daeho Kim
  • Publication number: 20140071716
    Abstract: A single switch PFC power supply (including forward and fly-back power supply) in single stage has two transformers: one forward transformer, one main transformer. The main transformer transfers electrical power from the primary circuit to secondary circuit. The forward transformer is used to correct input current waveform. The two transformer's primary windings are connected in series. An extra winding of the forward transformer, a capacitor and two diodes are formed a no loss snubber circuit to enhance the efficiency of the power supply.
    Type: Application
    Filed: August 30, 2013
    Publication date: March 13, 2014
    Inventor: Fuxiang Lin
  • Patent number: 8670248
    Abstract: This invention provides a primary-side controlled power converter comprising: an RC network coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer for generating a reflected signal, and a controller coupled to the RC network to receive the reflected signal for generating a switching signal; wherein the RC network develops a zero to provide a high-frequency path for shortening a rising time and a settling time of the reflected signal.
    Type: Grant
    Filed: July 15, 2011
    Date of Patent: March 11, 2014
    Assignee: System General Corporation
    Inventor: Ta-Yung Yang
  • Publication number: 20140063864
    Abstract: An electronic device includes a magnetic element, a first circuit module and a second circuit module. The magnetic component includes a magnetic core set and a winding, and the winding includes a first winding and a second winding, and the winding is assembled on the magnetic core set. The first circuit module is connected to the first winding of the magnetic element. The second circuit module is connected to the second winding of the magnetic element. The first circuit module or/and the second circuit module has/have an overlap portion with the winding on a vertical projection area of a first plane, and the first plane is the first plane is a horizontal plane at which the winding is located.
    Type: Application
    Filed: November 11, 2013
    Publication date: March 6, 2014
    Applicant: DELTA ELECTRONICS, INC.
    Inventors: Teng Liu, Ming-Hui Dai, Ke Dai
  • Patent number: 8665612
    Abstract: A constant current controller for a constant current power module, including: a demagnetization sensing unit, used for detecting the voltage variation of a detection signal to generate a discharging time signal having an active period corresponding to a secondary side discharging time, wherein the detection signal is derived from an auxiliary coil; a secondary side current sensing unit, used for detecting a peak value of a current sensing signal, and providing an output current according to the peak value of the current sensing signal under the control of the discharging time signal, wherein the current sensing signal is corresponding to a primary side current; and an error current generator, used for generating an error current according to the difference between the output current and a reference current, wherein the error current is converted to a threshold voltage by a first capacitor.
    Type: Grant
    Filed: July 10, 2012
    Date of Patent: March 4, 2014
    Assignee: Immense Advance Technology Corporation
    Inventors: Wei-Chuan Su, Wei-Chun Hsiao
  • 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
  • Publication number: 20140056036
    Abstract: An AC-to-DC power converter with a BJT as a power switch can set a base current of the BJT by a current setting resistor which is in the outside of a control integrated circuit. Since an output current and a recovery current of the BJT are injected into a sensing resistor, the AC-to-DC power converter can correctly detect an inductor current thereof from the sensing resistor.
    Type: Application
    Filed: August 22, 2013
    Publication date: February 27, 2014
    Applicant: Richtek Technology Corporation
    Inventors: Jiun-Hung PAN, Chien-Fu TANG, Jyun-Che HO, Isaac Y. CHEN, Yu-Chang CHEN, Jung-Pei CHENG
  • 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: 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
  • Publication number: 20140043863
    Abstract: A method of controlling a switching mode power converter enables zero voltage switching by forcing a voltage across the main switch to zero. This is accomplished by sensing when a current on the secondary side of the power converter drops to zero, or other threshold value, and then generating a negative current through the secondary winding in response. The negative secondary current results in a corresponding discharge current in the primary winding, which reduces the voltage across the main switch. The voltage across the main switch is monitored such that when the voltage reaches zero, or other threshold value, the main switch is turned ON. In this manner, the circuit functions as a bi-directional current circuit where a forward current delivers energy to a load and a reverse current provides control for reducing the voltage across the main switch to enable zero voltage switching.
    Type: Application
    Filed: August 13, 2012
    Publication date: February 13, 2014
    Applicant: FLEXTRONICS AP, LLC
    Inventors: Mark Telefus, Wei Li
  • Publication number: 20140043866
    Abstract: Disclosed herein are high efficiency, low loss AC-DC power supply circuits, and associated control methods. In one embodiment, an AC-DC power supply circuit can include: (i) a rectifier configured to rectify an AC power supply to generate a DC input voltage; (ii) a first stage voltage converter configured to convert the DC input voltage to a first output voltage, and to convert a first control signal to a feedback signal that represents the first output voltage; and (iii) a second stage voltage converter configured to convert the first output voltage to a constant DC output signal, where the first control signal represents a duty cycle of the second stage voltage converter.
    Type: Application
    Filed: July 9, 2013
    Publication date: February 13, 2014
    Inventors: Chen Zhao, Jie Yao
  • Patent number: 8649192
    Abstract: A power-supply includes a power-supply input. A transformer has a primary winding and a secondary winding separated galvanically from the primary winding. A controlled semiconductor switch has a control input in series circuit with the primary winding, which lies parallel to the power-supply input. A controllable control circuit for the semiconductor switch delivers a periodic control signal, which is controlled such that the output voltage on the secondary winding is kept at a desired value independent of the load, to the semiconductor switch. A voltage limiting circuit lies parallel to the input side of the primary winding. An output signal of the voltage limiting circuit acts on the switch state of the semiconductor switch to move the semiconductor switch to a stationary state, in which it generates no alternating current on the primary winding, when the voltage on the primary winding has exceeded a specified limiting value.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: February 11, 2014
    Assignee: R. Stahl Schaltgerate GmbH
    Inventor: Fritz Frey
  • Patent number: 8649191
    Abstract: A synchronous rectifier for a switching power converter is provided and includes a power transistor, a diode, and a control circuit. The power transistor and the diode are coupled to a transformer and an output of the power converter for the rectification. The control circuit generates a drive signal to switch on the power transistor once the diode is forward biased. The control circuit includes a phase-lock circuit. The phase-lock circuit generates an off signal to switch off the power transistor in response to a pulse width of the drive signal. The pulse width of the drive signal is shorter than a turned-on period of the diode. The phase-lock circuit further reduces the pulse width of the drive signal in response to a feedback signal. The feedback signal is correlated to an output load of the power converter.
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: February 11, 2014
    Assignee: System General Corporation
    Inventors: Ta-Yung Yang, Chou-Sheng Wang, Rui-Hong Lu
  • Publication number: 20140036550
    Abstract: A control circuit of an isolated flyback power converter providing bidirectional communication. The control circuit includes a pulse width modulation circuit, an oscillator, a primary transceiver, a secondary error amplifier and a secondary transceiver. The primary transceiver generates a feedback signal and a pulse-position signal. The secondary error amplifier generates an error signal in accordance with an output voltage of the power converter. The secondary transceiver generates a pulse modulation signal for transmitting the data from the secondary side to the primary side, and generates a frequency signal in response to a switching voltage of the transformer. The frequency signal is demodulated as the data transmitted from the primary side to the secondary side. The feedback signal is correlated to the error signal. The pulse-position signal is correlated to the pulse modulation signal. The error signal and the pulse modulation signal are coupled to an input of an optical coupler.
    Type: Application
    Filed: August 6, 2012
    Publication date: February 6, 2014
    Inventors: Ru-Shiuan Yang, Hung-Chi Chen
  • Publication number: 20140036549
    Abstract: A secondary-side dynamic load detection system and method rapidly identifies when a dynamic load has been placed on the output (e.g., when an electronic device is re-connected to the switching power converter). Once a dynamic load condition has been detected by the secondary side detector, a dynamic load detection signal is communicated from the secondary side of the switching power converter to a switch controller on the primary side. The switch controller can then quickly adapt switching in response to the dynamic load condition.
    Type: Application
    Filed: July 31, 2012
    Publication date: February 6, 2014
    Applicant: IWATT INC.
    Inventor: Yong Li
  • Patent number: 8644036
    Abstract: In conventional multi-output switching power supply device, power is supplied from a relatively high voltage side output to a relatively low voltage side output through a dropper circuit which generates relatively large power loss so as to improve the voltage accuracy of a non-stabilized output, so that power supply efficiency is low and heat generated from the dropper circuit is high. One DC power supply of a plurality of DC power supplies on the secondary side is a stabilized output (24 V output terminal TM3) having a voltage stabilizing means for stabilizing the output voltage by feeding back the output voltage to a primary side control circuit 4, and the rest of the DC power supplies are non-stabilized outputs (12 V output terminals TM4) not having a voltage stabilizing means for feeding back the output voltage to the primary side.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: February 4, 2014
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Makoto Sato, Yoichi Kyono
  • Patent number: 8643302
    Abstract: According to one embodiment, a switching power-supply device includes a switching element, a constant current element, a rectifying element, first and second inductors, and a constant voltage circuit. The switching element supplies, when the switching element is on, a power-supply voltage of a direct-current power supply to and feeds an electric current to the first inductor. The constant current element is connected to the switching element in series and turns off the switching element when the electric current of the switching element exceeds a predetermined current value. The rectifying element is connected to any one of the switching element and the constant current element in series. The second inductor is magnetically coupled to the first inductor and supplies induced potential to a control terminal of the switching element. The constant voltage circuit applies control potential to a control terminal of the constant current element.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: February 4, 2014
    Assignee: Toshiba Lighting & Technology Corporation
    Inventors: Noriyuki Kitamura, Yuji Takahashi
  • Publication number: 20140022823
    Abstract: An isolated flyback converter having temperature compensation (TC) uses primary side sensing and an output diode, the output diode having a variable voltage drop related to its temperature. A feedback voltage VFB, proportional to the output voltage VOUT, in a feedback loop is compared to a fixed reference voltage VREF for setting a duty cycle of a power switch, wherein VFB is caused to approximately equal VREF. A TC circuit has a voltage source configured to generate a proportional-to-absolute-temperature voltage VPTAT, wherein VPTAT is at approximately VREF at a calibration temperature T0 and rises as a temperature exceeds T0. The voltage source is connected to the VFB node via a TC resistor RTC, so that at T0 no current flows through RTC. Therefore, the selection of the optimal RTC does not affect the selection of a scaling resistance for generating VFB. The current through RTC at elevated temperatures compensates VOUT.
    Type: Application
    Filed: July 18, 2012
    Publication date: January 23, 2014
    Applicant: LINEAR TECHNOLOGY CORPORATION
    Inventors: Min Chen, John David Morris, Michael George Negrete
  • Publication number: 20140022824
    Abstract: System and method for regulating an output voltage of a power conversion system. The system includes an error amplifier coupled to a capacitor. The error amplifier is configured to receive a reference voltage, a first voltage, and an adjustment current and to generate a compensation voltage with the capacitor. The first voltage is associated with a feedback voltage. Additionally, the system includes a current generator configured to receive the compensation voltage and generate the adjustment current and a first current, and a signal generator configured to receive the first current and a second current. The signal generator is further configured to receive a sensing voltage and to generate a modulation signal. Moreover, the system includes the gate driver directly or indirectly coupled to the signal generator and configured to generate a drive signal based on at least information associated with the modulation signal.
    Type: Application
    Filed: September 23, 2013
    Publication date: January 23, 2014
    Applicant: ON-BRIGHT ELECTRONICS (SHANGHAI) CO., LTD.
    Inventors: Xiaomin Huang, Lieyi Fang
  • Publication number: 20140016372
    Abstract: Method and apparatus for converting DC input power to DC output power. In one embodiment, the apparatus comprises a first flyback circuit and a second flyback circuit, coupled in parallel, for providing DC-to-DC conversion; and a controller for (i) determining a first peak current, based on a predetermined peak current, for operating the first flyback circuit, (ii) determining a second peak current, based on the predetermined peak current, for operating the second flyback circuit, and (iii) operating the first and the second flyback circuits at switching frequencies dependent on the first and the second peak currents, respectively, to achieve timing synchronization for interleaved operation of the first and the second flyback circuits.
    Type: Application
    Filed: September 16, 2013
    Publication date: January 16, 2014
    Applicant: Enphase Energy, Inc.
    Inventors: Martin Fornage, Mudhafar Hassan-Ali, Tarik H. Omar
  • Publication number: 20140016371
    Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Inventor: Sriram Chandrasekaran
  • Publication number: 20140016366
    Abstract: A constant current controller for a constant current power module, including: a demagnetization sensing unit, used for detecting the voltage variation of a detection signal to generate a discharging time signal having an active period corresponding to a secondary side discharging time, wherein the detection signal is derived from an auxiliary coil; a secondary side current sensing unit, used for detecting a peak value of a current sensing signal, and providing an output current according to the peak value of the current sensing signal under the control of the discharging time signal, wherein the current sensing signal is corresponding to a primary side current; and an error current generator, used for generating an error current according to the difference between the output current and a reference current, wherein the error current is converted to a threshold voltage by a first capacitor.
    Type: Application
    Filed: July 10, 2012
    Publication date: January 16, 2014
    Inventors: Wei-Chuan Su, Wei-Chun Hsiao
  • Publication number: 20140016368
    Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Applicant: POWER SYSTEMS TECHNOLOGIES, LTD.
    Inventor: Sriram Chandrasekaran
  • Publication number: 20140016361
    Abstract: A rectifier circuit includes first and second load terminals, a first semiconductor device having a load path and configured to receive a drive signal, and a plurality of second semiconductor devices each having a load path and each configured to receive a drive signal. The load paths of the second semiconductor devices are connected in series, and connected in series to the load path of the first semiconductor device. A series circuit with the first semiconductor device and the second semiconductor devices is connected between the load terminals. Each of the second semiconductor devices is configured to receive as a drive voltage either a load-path voltage of at least one of the second semiconductor devices, or a load-path of at least the first semiconductor device. The first semiconductor device is configured to receive as a drive voltage a load-path-voltage of at least one of the second semiconductor devices.
    Type: Application
    Filed: March 15, 2013
    Publication date: January 16, 2014
    Inventors: Rolf Weis, Gerald Deboy
  • Publication number: 20140016375
    Abstract: A switching mode power supply (SMPS) includes a transformer having a primary winding for coupling to an input power source, a secondary winding for providing an output voltage of the SMPS, and an auxiliary winding. The SMPS also has a power transistor coupled to the primary winding and a primary side control circuit coupled to the auxiliary winding and the power transistor. The primary side control circuit is configured to regulate the output of the SMPS by controlling the power switch in response to a feedback voltage signal that is representative of an output of the SMPS. The SMPs also has a secondary-side control circuit coupled to the secondary winding and being configured to cause the output voltage of the SMPS to discharge when the output voltage of the SMPS is higher than a first reference voltage.
    Type: Application
    Filed: December 7, 2012
    Publication date: January 16, 2014
    Applicant: BCD Semiconductor Manufacturing Limited
    Inventors: CHAO GAO, PINGAN ZHAO, CHAO CHEN
  • Publication number: 20140015432
    Abstract: According to one embodiment, a power supply device includes a full-wave rectifier, a power converting circuit, and a partial smoothing circuit. The power converting circuit converts an output of the full-wave rectifier into a direct-current voltage according to a switching action of a switching element. The partial smoothing circuit includes, in series, a capacitor and a first diode connected in polarity opposite to output polarity of the full-wave rectifier. The partial smoothing circuit is provided on an output side of the full-wave rectifier in parallel to the power converting circuit. In the partial smoothing circuit, the capacitor is charged according to the switching action of the switching element of the power converting circuit. The partial smoothing circuit supplies charged electric of the capacitor to the power converting circuit via the first diode in a trough portion of an output voltage of the full-wave rectifier.
    Type: Application
    Filed: September 14, 2012
    Publication date: January 16, 2014
    Applicant: Toshiba Lighting & Technology Corporation
    Inventors: Hirokazu OTAKE, Noriyuki KITAMURA, Yuji TAKAHASHI, Hiroshi AKAHOSHI
  • Publication number: 20140016370
    Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Applicant: POWER SYSTEMS TECHNOLOGIES, LTD.
    Inventor: Sriram Chandrasekaran
  • Publication number: 20140016367
    Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Applicant: POWER SYSTEMS TECHNOLOGIES, LTD.
    Inventor: Sriram Chandrasekaran
  • Publication number: 20140016369
    Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.
    Type: Application
    Filed: July 16, 2012
    Publication date: January 16, 2014
    Applicant: POWER SYSTEMS TECHNOLOGIES, LTD.
    Inventor: Sriram Chandrasekaran
  • Patent number: 8630102
    Abstract: A power converter includes a dc input having first and second terminals. A main converter is coupled to the first terminal of the dc input. A standby circuit coupled to the second terminal of the dc input and the main converter. The main converter is coupled to control a transfer of energy from the dc input through the standby circuit to a main output of the main converter during a normal operating condition of the power supply. The standby circuit is coupled to decouple the main converter from the second terminal of the dc input during a standby operating condition of the power converter. A standby converter is coupled to the first and second terminals of the dc input to control a transfer of energy from the dc input to a standby output of the standby converter during the standby operating condition of the power converter.
    Type: Grant
    Filed: January 8, 2013
    Date of Patent: January 14, 2014
    Assignee: Power Integrations, Inc.
    Inventors: Balu Balakrishnan, David Michael Hugh Matthews
  • Publication number: 20140009973
    Abstract: An exemplary embodiment of the present invention relates to a power supply. A power supply according to an exemplary embodiment of the present invention includes: a filter capacitor coupled to a line to which an input voltage rectified from an AC input passed through a dimmer is supplied; a discharge switch coupled to the filter capacitor through the line; and a main switch receiving the input voltage and controlling power transmission. The power supply performs input voltage control to shape the input voltage with a predetermined pattern and controls a switching operation time of the main switch.
    Type: Application
    Filed: June 18, 2013
    Publication date: January 9, 2014
    Applicant: Fairchild Korea Semiconductor Ltd.
    Inventors: Hyun-Chul EOM, Young-Jong KIM, In-Ki PARK
  • Publication number: 20140009974
    Abstract: Embodiments disclose control methods and control apparatuses for a switched mode power supply. The switched mode power supply comprises a current-controllable device. A driving current is provided to turn ON the current-controllable device. A conduction current passing through the current-controllable device is detected. The driving current is controlled according to the conduction current. The higher the conduction current the higher the driving current.
    Type: Application
    Filed: March 15, 2013
    Publication date: January 9, 2014
    Applicant: LEADTREND TECHNOLOGY CORPORATION
    Inventors: Yi-Lun Shen, Yu-Yun Huang
  • Patent number: 8625311
    Abstract: In a switching power supply apparatus, a comparator outputs a first determination criterion signal based on a saw-tooth wave signal whose level fluctuates with a constant period and a detection voltage signal. An inverter subjects the first determination criterion signal to reverse processing, and outputs a second determination criterion signal. The comparator outputs a first switching judgment-use signal from a monitor signal and a threshold value, and the comparator outputs a second switching judgment-use signal from the monitor signal and the threshold value. An AND circuit outputs the first switching control signal from the first determination criterion signal and the first switching judgment-use signal, and the AND circuit outputs the second switching control signal from the second determination criterion signal and the second switching judgment-use signal.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: January 7, 2014
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tatsuya Hosotani, Yoshiyuki Uno
  • Patent number: 8625312
    Abstract: A switching circuit for use in a power converter includes a first active switch coupled between a first terminal of an input of the power converter and a first terminal of a primary winding of a transformer. A second active switch is coupled between a second terminal of the input and a second terminal of the primary winding. An output capacitance of the first active switch is greater than an output capacitance of the second active switch. A first passive switch is coupled between the second terminal of the primary winding and the first terminal of the input. A second passive switch is coupled between the second terminal of the input and the first terminal of the primary winding. A reverse recovery time of the first passive switch is greater than a reverse recovery time of the second passive switch.
    Type: Grant
    Filed: April 5, 2013
    Date of Patent: January 7, 2014
    Assignee: Power Integrations, Inc.
    Inventor: Robert J. Mayell
  • Patent number: 8624516
    Abstract: A power supply apparatus for LED is provided. The power supply apparatus for LED includes a detector, a voltage dropper, and a control switch. The detector detects whether an LED is connected to the power supply apparatus. The voltage dropper drops a voltage applied to the LED. The control switch is connected to the voltage dropper in parallel, and changes a path of a power applied to the LED according to the detected result of the detector. Accordingly, the power supply apparatus for LED compensates for a low impedance of an LED to an impedance equal to or higher than a predetermined impedance at a time when connection of the LED is detected, thereby inhibiting an overcurrent from flowing in the LED.
    Type: Grant
    Filed: June 20, 2011
    Date of Patent: January 7, 2014
    Assignee: LG Innotek Co., Ltd.
    Inventors: Ui Jong Kim, Min Ho Kim
  • Patent number: 8619440
    Abstract: Control methods and controller thereof for a power supply including a power switch and an inductor. The power switch is turned on to increase the inductor current through the inductor, which is sensed to generate a current-sense signal. The current-sense signal is added up with an adjusting signal to generate a summation signal. The power switch is turned off if the summation signal is higher than a peak limit. The turn-on time of the power switch is detected to update the adjusting signal.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: December 31, 2013
    Assignee: Leadtrend Technology Corp.
    Inventors: Kuo-Chien Huang, Ren-Yi Chen, Wen-Chung Yeh
  • Patent number: 8619439
    Abstract: A flyback boost circuit includes an output voltage detection terminal provided to a secondary winding of a transformer of the flyback boost circuit, and configured to detect an output voltage. Prior to the start of a boost operation, current is supplied to a secondary side of the transformer via the output voltage detection terminal to detect a voltage generated at the output voltage detection terminal, to thereby detect an unwired state by determining whether or not there is floating of the output voltage detection terminal or a grounding terminal of the secondary winding of the transformer.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: December 31, 2013
    Assignee: Sony Corporation
    Inventors: Katsuya Ikezawa, Kunio Kinoshita, Takuya Takenaka, Yasuhiro Yamawaki, Tatsuo Kuroiwa
  • Publication number: 20130343100
    Abstract: In fly-back and buck-boost converters (21, 22), to reduce distortions and to increase distortion power factors, arrangements (1) are introduced for adjusting control signals generated by controllers (2) for controlling switches (3) of the converters. The arrangements (1), in response to increased/decreased amplitudes of voltage signals from voltage supplies (4) for feeding the converters, increase/decrease durations of conducting times of the switches (3). This way, unwanted losses in the grid and power generators are avoided. The converters are relatively low cost single stage converters. Preferably, the durations are substantially proportional to sums of the amplitudes of the voltage signals and design parameters. These design parameters may comprise amplitudes of other voltage signals such as output voltages. Arrangements (1) are provided for controllers (2) that can only produce fixed durations as well as for controllers (2) that can produce adaptable durations via adaptable external elements.
    Type: Application
    Filed: February 24, 2012
    Publication date: December 26, 2013
    Applicant: KONINKLIJKE PHILIPS N.V.
    Inventor: Willibrordus Jurrianus Dijkman