Having Current Protection Patents (Class 363/56.1)
  • Patent number: 7760518
    Abstract: Techniques are disclosed to detect a fault in the feedback circuit of a switching power supply while the power supply operates in a mode where the output is below its regulated value. The power supply delivers maximum power at a given switching frequency without a feedback signal while the output is below its regulated value. A fault protection circuit substantially reduces the average output power if there is no feedback signal for the duration of a fault time. When there is no feedback signal, the power supply increases the maximum output power by increasing the switching frequency before the end of the fault time to increase the output to a regulated value. The presence of a feedback signal when the output reaches a regulated value restores the original switching frequency and returns the output to its unregulated value. The absence of a feedback signal at the end of the fault time engages the fault protection circuit to substantially reduce the output power.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: July 20, 2010
    Assignee: Power Integrations, Inc.
    Inventors: Stefan Bäurle, William M. Polivka
  • Patent number: 7684220
    Abstract: System and method for protecting a power converter. A system includes a threshold generator configured to generate a threshold signal, and a first comparator configured to receive the threshold signal and a first signal and to generate a comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and adjust the input current for the power converter. The threshold signal is associated with a threshold magnitude as a function of time. The threshold magnitude increases with time at a first slope during a first period, and the threshold magnitude increases with time at a second slope during a second period. The first slope and the second slope are different.
    Type: Grant
    Filed: May 24, 2007
    Date of Patent: March 23, 2010
    Assignee: On-Bright Electronics (Shanghai) Co., Ltd.
    Inventors: Lieyi Fang, Shifeng Zhao, Bo Li, Zhiliang Chen
  • Publication number: 20100008106
    Abstract: At the starting time and an overload time in which the output voltage of the switching power source apparatus is low, if an overcurrent state, in which the ON period of the switching device becomes short and a current not less than the current limit value of the switching device flows through the switching device, occurs, this overcurrent state is detected. The blanking period of a blanking pulse signal is made shorter than the blanking period that is obtained during steady operation, and the ON period of the switching device is made shorter. Hence, the device current flowing through the switching device can be made small in each pulse for the switching operation, and, at the same time, the device current is suppressed from increasing each time a pulse for the switching operation is generated.
    Type: Application
    Filed: July 8, 2009
    Publication date: January 14, 2010
    Applicant: Panasonic Corporation
    Inventors: Keita Kawabe, Kazuhiro Murata, Yoshihiro Mori, Naohiko Morota
  • Publication number: 20090310389
    Abstract: A method for controlling a power supply is disclosed. An example method includes deactivating the power supply in response to a first current through a first terminal of a power supply controller falling below a first threshold value. The power supply is activated in response to the first current through the first terminal rising above a second threshold value. Deactivating the power comprises causing a power switch coupled to a primary winding of the power supply not to receive a switching waveform for more than one cycle until the power supply is activated.
    Type: Application
    Filed: August 20, 2009
    Publication date: December 17, 2009
    Applicant: POWER INTEGRATIONS, INC.
    Inventors: Balu Balakrishnan, Alex B. Djenguerian, Leif O. Lund
  • Patent number: 7619909
    Abstract: A control circuit for adjusting leading edge blanking time is disclosed. The control circuit is applied to a power converting system. The control circuit adjusts a leading edge blanking time according to a feedback signal relative to a load connected to the output terminal of the power converting system. An over-current protection mechanism of the power converting system is disabled within the leading edge blanking time.
    Type: Grant
    Filed: December 7, 2007
    Date of Patent: November 17, 2009
    Assignee: Leadtrend Technology Corp.
    Inventors: Yuan-Wen Chang, Yu-Bin Wang, Ming-Nan Chuang, Yu-Chuan Liu
  • Patent number: 7616461
    Abstract: The present invention provides a method and a control circuit to detect an input voltage for the control and protections of a power converter. It includes a current sense circuit for generating a current signal in response to a switching current of a transformer. A detection circuit is coupled to sense the current signal for generating a slope signal in response to a slope of the current signal. A protection circuit is further developed to control the switching signal in accordance with the slope signal. The level of the slope signal is corrected to the input voltage of the power converter.
    Type: Grant
    Filed: January 12, 2007
    Date of Patent: November 10, 2009
    Assignee: System General Corp.
    Inventors: Ta-yung Yang, Chien-Yuan Lin
  • Publication number: 20090231892
    Abstract: An uninterruptible power supply (UPS) system includes an AC power input configured to receive AC power from a single-phase AC power source or a multi-phase AC power source, a DC power source, an output circuit including a power output, a controllable switch configured to selectively couple at least one of the AC power input and the DC power source to the output circuit, and a processor coupled and configured to affect operation of the output circuit depending upon which of single-phase and multi-phase operation of the UPS is indicated.
    Type: Application
    Filed: March 11, 2009
    Publication date: September 17, 2009
    Applicant: AMERICAN POWER CONVERSION CORPORATION
    Inventors: DAMIR KLIKIC, MIRZA A. BEG, MARK R. MELANSON, EDWARD KOTLYAR, JEFFREY B. SAMSTAD
  • Patent number: 7570498
    Abstract: A switching power supply apparatus has a switching device control circuit for performing overcurrent protection by controlling switching-on/off of a switching device, connected serially to a primary winding of a transformer, so as to make a voltage output from a rectifying and smoothing circuit, connected to a secondary winding of the transformer, have a specific value, and switching off the switching device when the electric current flowing through the switching device exceeds a value as an overcurrent detection point.
    Type: Grant
    Filed: February 6, 2007
    Date of Patent: August 4, 2009
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Tetsuya Niijima
  • Patent number: 7567070
    Abstract: Techniques are disclosed to adjust a current limit in a switching regulator. One example switching regulator includes a comparator having first and second inputs and an output. The first input of the comparator is adapted to sense a current flow through a switch and the second input of the comparator is adapted to sense a variable current limit value. A controller is coupled to the output of the comparator and to the switch to control switching of the switch to regulate an output of a power supply in response a feedback signal. The controller disables the switch if the sensed current flow through the switch is greater than the sensed variable current limit value. The variable current limit value is set to a first variable current limit value by the controller in response to an input line voltage of the power supply if there is not an over current condition during a first switching cycle that occurs after a skipped switching cycle of the switch.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: July 28, 2009
    Assignee: Power Integrations, Inc.
    Inventors: Alex B. Djenguerian, Stefan Bäurle, Kent Wong
  • Patent number: 7564704
    Abstract: In one embodiment, a power supply controller is configured to switch a power switch of a power supply when a voltage across the switch is at a minimum value.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: July 21, 2009
    Assignee: Semiconductor Components Industries, L.L.C.
    Inventors: Antonin Rozsypal, Roman Stuler, Karel Ptacek
  • Patent number: 7558084
    Abstract: A switching mode power supply includes a power supply, a feedback circuit, and a switching controller. The power supply includes a main switch coupled to a primary coil of a transformer and supplies power to a secondary coil of the transformer according to an operation of the main switch. The feedback circuit generates a feedback voltage corresponding to an output voltage applied to the secondary coil. The switching controller compensates a propagation delay by controlling a duty of the main switch according to a result of comparing a first signal that fluctuates according to a first voltage corresponding with a current flowing through the main switch to a reference voltage corresponding to the feedback voltage.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: July 7, 2009
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventor: Kyung Oun Jang
  • Patent number: 7558091
    Abstract: The switching power supply apparatus includes detection means for detecting that leak current of an input smoothing capacitor becomes a predetermined value or more and first auxiliary switching means connected in series with respect to the input smoothing capacitor. The first auxiliary switching means becomes an on state during a normal operation, whereas the first auxiliary switching means goes into an off state in a case where the detection means detects that the leak current of the input smoothing capacitor becomes a predetermined value or more.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: July 7, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Haruo Nishi
  • Patent number: 7551464
    Abstract: The present invention provides a method for preventing current overloading and saturation of a switch power supply, including one of the steps of checking whether a primary current of an transformer, and a current of an induction or a current of field effect transistor being excess an upper limit current; and a step for generating an adjusting signal so as to directly or indirectly adjust an error signal if the upper limit current is excess the upper limit, so that during subsequent pulse adjustable periods, a duty cycle is reduced, the primary current or the induction current or field effect transistor peak current value are reduced.
    Type: Grant
    Filed: July 18, 2006
    Date of Patent: June 23, 2009
    Inventor: Weibin Chen
  • Patent number: 7539028
    Abstract: Techniques are disclosed to detect a fault in the feedback circuit of a switching power supply while the power supply operates in a mode where the output is below its regulated value. The power supply delivers maximum power at a given switching frequency without a feedback signal while the output is below its regulated value. A fault protection circuit substantially reduces the average output power if there is no feedback signal for the duration of a fault time. When there is no feedback signal, the power supply increases the maximum output power by increasing the switching frequency before the end of the fault time to increase the output to a regulated value. The presence of a feedback signal when the output reaches a regulated value restores the original switching frequency and returns the output to its unregulated value. The absence of a feedback signal at the end of the fault time engages the fault protection circuit to substantially reduce the output power.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: May 26, 2009
    Assignee: Power Integrations, Inc.
    Inventors: Stefan Bäurle, William M. Polivka
  • Patent number: 7538533
    Abstract: Various techniques directed to providing temporary peak power from a switching regulator are disclosed. In one aspect, a switching regulator includes a switch that is to be coupled between a power supply input and an energy transfer element of the power supply. A controller is coupled to be responsive to a feedback signal to be received from an output of the power supply. The controller is coupled to switch the switch in response to the feedback signal to regulate the output of the power supply. An oscillator is coupled to provide an oscillating signal to the controller to determine a maximum switching frequency of the switch. The oscillating signal is coupled to oscillate at a first frequency under a first moderate load condition at the power supply output. The oscillating signal is coupled to oscillate at a second frequency under a second peak load condition at the power supply output.
    Type: Grant
    Filed: May 22, 2008
    Date of Patent: May 26, 2009
    Assignee: Power Integrations, Inc.
    Inventors: Stefan Bäurle, David Michael Hugh Matthews, William M. Polivka
  • Patent number: 7535736
    Abstract: A switching power supply has a switching device connected via a primary winding of a transformer to DC input voltage; a circuit for rectifying voltage at a secondary winding of the transformer, and outputting an output signal; and a control circuit for controlling on/off states of the switching device. The control circuit detects a current signal generated based on a forward voltage generated at a drive winding of the transformer while the switching device is on; generates an input correction signal using the current signal, the level of the input correction signal varying in accordance with the DC input voltage; detects a signal of current flowing through the switching device; and compares the input correction signal with the signal of the current flowing through the switching device, and limits the maximum value of this current in accordance with the DC input voltage.
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: May 19, 2009
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Masaru Nakamura, Masaaki Shimada
  • Patent number: 7525826
    Abstract: Configurations provide reduction in the hum and the weak shocks that are produced in audio equipments where electrical power is supplied. Switching electrical power sources include, a rectification element that rectifies a current that is supplied, a switching element that switches the input voltage that has been rectified by the rectification element, an oscillator circuit that oscillates at a specified frequency and drives the switching element by means of oscillation, and a transformer with which the voltage that has been switched by the switching element is input to the primary oil and wherein an electrical power source output is obtained from a secondary coil. A plurality of capacitors are connected to the conductors.
    Type: Grant
    Filed: April 13, 2007
    Date of Patent: April 28, 2009
    Assignee: Roland Corporation
    Inventors: Hoichi Iwamoto, Hiroshi Emoto
  • Publication number: 20090097284
    Abstract: In the present invention, an on time is used which increases at an instantaneous interruption. The on time is detected by a MAX-DUTY detector 10 and the overload protection function of an overload protection circuit 150 is disabled.
    Type: Application
    Filed: September 29, 2008
    Publication date: April 16, 2009
    Applicant: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tomoaki Takei, Tetsuji Yamashita, Kazuhiro Murata, Yoshihiro Mori
  • Patent number: 7518893
    Abstract: A method for operation of a converter circuit is specified, wherein the converter circuit has a converter unit with a multiplicity of drivable power semiconductor switches and an LCL filter which is connected to each phase connection of the converter unit, in which method the drivable power semiconductor switches are driven by means of a drive signal which is formed from reference voltages. The reference voltages are formed by subtraction of damping voltages from reference-phase connection voltages, with the damping voltages being formed from filter capacitance currents, weighted with a variable damping factor of the LCL filter. An apparatus for carrying out the method is also specified.
    Type: Grant
    Filed: July 16, 2007
    Date of Patent: April 14, 2009
    Assignee: ABB Schweiz AG
    Inventors: Srinivas Ponnaluri, Jürgen Steinke
  • Patent number: 7489120
    Abstract: A high voltage power supply method and apparatus is disclosed. An apparatus according to aspects of the present invention includes a power supply circuit having a rectifier circuit coupled to input terminals of the power supply circuit that are to be coupled to receive an AC input voltage. A switchmode power converter circuit is coupled to the rectifier circuit to receive a rectified input voltage to generate a regulated output voltage in response to the rectified input voltage. A switch is coupled between the rectifier circuit and the switchmode power converter circuit. A sense circuit is coupled to detect the AC input voltage. The switch is coupled to be switched in response to the sense circuit. The switch is coupled to be switched off when an absolute value of the AC input voltage exceeds a first threshold value. The switch is coupled to be switched on when the absolute value of the AC input voltage is below a second threshold value.
    Type: Grant
    Filed: July 12, 2006
    Date of Patent: February 10, 2009
    Assignee: Power Integrations, Inc.
    Inventor: David Michael Hugh Matthews
  • Publication number: 20090034302
    Abstract: A DC-DC converter including: a switch, having a control terminal receiving a control signal, and a conduction terminal supplying a current; a load, coupled to the conduction terminal of the switch and selectively receiving the current; a control circuit, receiving a clock signal and generating the control signal in synchronism with the clock signal; an overcurrent sensor, coupled to the switch so as to monitor an electrical quantity correlated to the current and to output a protection signal in presence of overcurrent; moreover including overcurrent-protection circuitry, receiving the protection signal and the clock signal and generating a disabling signal for the control circuit if delay between an overcurrent detection and the clock signal is shorter than a detection time.
    Type: Application
    Filed: July 29, 2008
    Publication date: February 5, 2009
    Applicant: STMicroelectronics S.r.I.
    Inventors: Eliana Cannella, Filippo Marino
  • Patent number: 7411374
    Abstract: A capacitor charging circuit comprises, power transfer circuitry, power switching control circuitry and voltage measurement circuitry. The power transfer circuitry transfers power from a power source to a capacitor. The power switching control circuitry controls the switching that causes power to be delivered to the power transfer circuitry. The voltage measurement circuitry indirectly measures the output voltage to determine when to stop charging the capacitor.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: August 12, 2008
    Assignee: 02Micro Intermnational Limited
    Inventors: Seeteck Tan, Vlad Mihall Popescu-Stanesti
  • Patent number: 7391629
    Abstract: Disclosed is an SMPS for preventing abnormal overcurrents. A circuit having a short circuit delay is used to generate a control signal for turning off a main switch (i.e., a switching MOS transistor) when the overcurrent occurs, that is, in an initial startup or when a protection circuit is operated. Accordingly, a drain-source voltage of the main switch is reduced when the main switch is turned off, and a switching MOS transistor with a low withstanding voltage can be used.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: June 24, 2008
    Assignee: Fairchild Korea Semiconductor, Ltd.
    Inventors: Young-Chul Ryu, Jin-Ho Choi
  • Patent number: 7388360
    Abstract: Various techniques directed to providing temporary peak power from a switching regulator are disclosed. In one aspect, a switching regulator includes a switch that is to be coupled between a power supply input and an energy transfer element of the power supply. A controller is coupled to be responsive to a feedback signal to be received from an output of the power supply. The controller is coupled to switch the switch in response to the feedback signal to regulate the output of the power supply. An oscillator is coupled to provide an oscillating signal to the controller to determine a maximum switching frequency of the switch. The oscillating signal is coupled to oscillate at a first frequency under a first moderate load condition at the power supply output. The oscillating signal is coupled to oscillate at a second frequency under a second peak load condition at the power supply output.
    Type: Grant
    Filed: May 23, 2007
    Date of Patent: June 17, 2008
    Assignee: Power Integrations, Inc.
    Inventors: Stefan Bäurle, William M. Polivka, David Michael Hugh Matthews
  • Patent number: 7375990
    Abstract: Electric current supplied to the primary side winding of a switching transformer is switched to generate ac power respectively in a plurality of secondary side windings of the switching transformer. A switching control signal is optically transmitted depending on the voltage of dc power obtained by rectifying and smoothing the ac power generated in the secondary side windings of the switching transformer and whether or not the output side of an electronic circuit connected to the secondary side windings of the switching transformer is short-circuited. When the short-circuit of the output side of the electronic circuit is detected, a switching operation is stopped in accordance with the transmitted switching control signal.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: May 20, 2008
    Assignee: Funai Electric Co., Ltd.
    Inventor: Akira Muramatsu
  • Patent number: 7359221
    Abstract: A three-phase electronic electricity meter that includes a power supply circuit operable to create a constant voltage output when receiving a variable voltage input. The power supply circuit of the electricity meter receives a three-phase line voltage and converts the variable three phase line voltage to a constant DC output. The power supply circuit includes a current limiting circuit to suspend operation of the power converter when the current exceeds a selected value. The power supply circuit includes an over voltage protection that limits the maximum voltage applied to the switching component of the power supply circuit. Both the over voltage protection circuit and the current limiting circuit suspend operation of the power converter to prevent damage to the operating components of the power supply circuit.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: April 15, 2008
    Assignee: M&FC Holding, LLC
    Inventor: Alex C. Knill
  • Patent number: 7352136
    Abstract: A DC-DC converter reduces a surge voltage developed across a switching element (30) in making the voltage conversion with the use of a transformer (20) inherently having considerable leakage. A snubber circuit is included to absorb the surge energy and transferring it to a load, or output end of the converter, reducing the surge voltage across the switching element (30). A snubber capacitor (51) is provided to absorb the surge energy developed by the transformer (20) when the switching element (30) is off. Thus absorbed energy is collected in a storage capacitor (53) through a reactor (54) while the switching element (30) is on and off, and is then transferred from the storage capacitor (53) to the load, i.e., the output side of the converter, leaving only a minimum voltage being applied across the switching element (30).
    Type: Grant
    Filed: March 2, 2004
    Date of Patent: April 1, 2008
    Assignee: Matsushita Electric Works, Ltd.
    Inventor: Takashi Kambara
  • Patent number: 7339804
    Abstract: A DC-DC converter of the present invention includes: an activation circuit which activates a control circuit for controlling a turning on and off of a switching element; a second rectifying and smoothing circuit which supplies an output voltage, as a power supply, to the control circuit, the output voltage being obtained by rectifying and smoothing a voltage in a tertiary winding of a transformer; an overcurrent protection circuit which limits an output current to be supplied to a load when overloaded; an overcurrent detection circuit which detects that the load is in an overcurrent state, and which outputs a detection signal during a period when the overcurrent protection circuit is operated; and an activation current switching circuit which switches outputs from the activation circuit.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: March 4, 2008
    Assignee: Sanken Electric Co., Ltd.
    Inventor: Akihiro Uchida
  • Patent number: 7301786
    Abstract: A quasi resonant type switching power supplying unit includes an overcurrent limiting circuit and an oscillation level comparison circuit. The overcurrent limiting circuit (i.e., a level determining circuit and a reference voltage generating circuit) receives a reverse electromotive voltage generated from an auxiliary winding which is electromagnetically connected with a primary winding when a MOSFET is in an OFF state, and produces a reference voltage stepwise based on the reverse electromotive voltage. The oscillation level comparison circuit receives a feedback voltage corresponding to electric power supplied to a load, and produces a control signal that switches the MOSFET into an OFF state when the feedback voltage exceeds the reference voltage.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: November 27, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasunari Noguchi, Yoshio Fujimura
  • Patent number: 7275002
    Abstract: An islanding detection and protection method of a parallel-type power converter is proposed, which performs perturbation to a power system to detect the frequency of the system voltage and the variation of the magnitude of the negative-sequence voltage as the basis for deciding the occurrence of an islanding operation. When the system operates normally, the frequency or phase and magnitude of the system voltage and the magnitude of the negative-sequence voltage won't be affected by the perturbation. On the other hand, if an islanding operation occurs, this perturbation will cause an apparent drift of the frequency or phase and magnitude of the system voltage and the magnitude of the negative-sequence voltage. Through detection of this apparent drift, the perturbation can be amplified by means of positive feedback to quickly detect the islanding operation phenomenon and trigger the protection mechanism.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: September 25, 2007
    Assignee: Industrial Technology Research Institute
    Inventors: Yung-Fu Huang, Pao-Chuan Lin, Tain-Syh Luor
  • Patent number: 7239119
    Abstract: Various techniques directed to providing temporary peak power from a switching regulator are disclosed. In one aspect, a switching regulator includes a switch that is to be coupled between a power supply input and an energy transfer element of the power supply. A controller is coupled to be responsive to a feedback signal to be received from an output of the power supply. The controller is coupled to switch the switch in response to the feedback signal to regulate the output of the power supply. An oscillator is coupled to provide an oscillating signal to the controller to determine a maximum switching frequency of the switch. The oscillating signal is coupled to oscillate at a first frequency under a first moderate load condition at the power supply output. The oscillating signal is coupled to oscillate at a second frequency under a second peak load condition at the power supply output.
    Type: Grant
    Filed: November 5, 2004
    Date of Patent: July 3, 2007
    Assignee: Power Integrations, Inc.
    Inventors: Stefan Bäurle, William M. Polivka, David Michael Hugh Matthews
  • Patent number: 7075805
    Abstract: A voltage converter includes two input terminals, at least a current limiting portion, an electronic switch in the form of a transistor controlled by a control device in synchronization with the supply voltage, and a storage capacitor. Two output terminals taken from the storage capacitor supply the load, where the current limiting portion is formed by at least the primary of a transformer, and whose secondary output supplies a rectifier whose output terminals are connected to the load.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: July 11, 2006
    Assignee: Somfy SAS
    Inventor: Serge Bruno
  • Patent number: 7064943
    Abstract: A boost-type switching power device which obtains a dc output by connecting a rectifying diode to the output side of an inductance element, connected in series to a main switching element, the device including: a control circuit which controls the operation of the main switching element by using a feedback signal in accordance with the dc output; and a constant-current circuit comprising a plurality of active elements, which are provided between the the rectifying diode and the output terminal; and wherein, when there is an overload on the output side, the operation of the active elements comprising the constant-current circuit controls the control circuit, switching the main switching element off and thereby stopping the boost function, and, in addition, the output is controlled by the constant-current circuit.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: June 20, 2006
    Assignee: Toko Kabushiki Kaisha
    Inventor: Tetsushi Otake
  • Patent number: 6980443
    Abstract: Disposed in a secondary side circuit and is connected to a constant voltage control circuit (22), to an overcurrent detection circuit (24), and to an overvoltage detection circuit (26), a photocoupler control circuit (28) controls a photocoupler (IC1) so as to feed a constant voltage detection control signal as a feedback signal back to a primary side circuit. The photocoupler control circuit (28) controls the photocoupler (IC1) so as to turn it off when the photocoupler control circuit is supplied with at least one of an overcurrent detected signal and an overvoltage detected signal. A voltage detection circuit (18) makes a latch circuit (16) operate when the voltage detection circuit detects a voltage induced in an auxiliary winding (NSLD) of a transformer with the photocoupler turned off, thereby making a switching operation of a switching type AC adapter circuit stop.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: December 27, 2005
    Assignee: Mitsumi Electric Co., Ltd.
    Inventors: Junji Nagano, Kouji Murakami
  • Patent number: 6977803
    Abstract: An energy transfer element with substantially reduced electrical displacement current flow between an input circuit coupled to the energy transfer element input winding and an output circuit coupled to the energy transfer element output winding. In one aspect, an energy transfer element includes an input winding, an output winding, an electrically conductive shield coupled to the input winding and a first cancellation winding coupled to the input winding. The electrically conductive shield is physically positioned between input and output windings. The output winding is physically positioned between the electrically conductive shield and the first cancellation winding. The first cancellation winding is wound to substantially reduce a capacitive displacement current between the input circuit and the output circuit.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: December 20, 2005
    Assignee: Power Integrations, Inc.
    Inventor: Chan Woong Park
  • Patent number: 6975523
    Abstract: A power supply protecting the electric device circuit when over-voltage is applied, is provided. The power supply has a rectifying unit rectifying AC power externally supplied, into first and second DC power and outputting the first and the second DC power; a main power supply transformer boosting the first DC power and supplying the boosted first DC power to the electric device circuit; a switching controlling unit driven by the second DC power, performing the operation on the main power supply transformer that causes the first DC power to be boosted when the second DC power is received; and a controlling unit determining whether the second DC power is to be supplied to the switching controlling unit, wherein the controlling unit senses the voltage supplied to the electric device circuit and interrupts supplying the second DC power to the switching controlling unit if the sensed voltage exceeds a given value.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: December 13, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hyung-wan Kim, Gil-yong Chang
  • Patent number: 6865095
    Abstract: It is an object to provide a power circuit in which a space for providing a circuit to protect the power circuit can be reduced when a short circuit is generated on the secondary side of the transformer of the power circuit, and the size of the circuit can be decreased. A first coil (L1), a second coil (L2) and a third coil (L3) are provided on the primary side of a transformer (25) disposed on a power circuit (35). Moreover, a plurality of coils corresponding to the coils on the primary side is provided on the secondary side of the transformer (25).
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: March 8, 2005
    Assignee: Orion Electric Company, Ltd.
    Inventor: Katsuhiko Tani
  • Patent number: 6788556
    Abstract: A switching power source device includes a peak current limiting circuit in which peak current flowing through a first switching element is detected, and when the current reaches a predetermined value, transistors are turned on in succession to increase the quantity of an electrical signal whereby the first switching element is rapidly turned off, and an on-time limiting circuit for reducing the on-time using reduction of the output voltage. The switching power source device is operated so as to repeat starting and stopping due to a turn-on delay circuit when the output is shortcircuited for reduction of the shortcircuit current.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: September 7, 2004
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tatsuya Hosotani, Hiroshi Takemura
  • Patent number: 6744642
    Abstract: A transformer reset circuit includes a first capacitor serially connected to a transformer winding, a rectifier connected in parallel with the first capacitor and the transformer winding, a second capacitor, an auxiliary switch connected in series with the second capacitor to form a series circuit connected in parallel with the rectifier, and a switch control circuit. The switch control circuit can turn on the main switch and turn off the auxiliary switch to release magnetizing energy stored in an inductor to charge the first capacitor. The auxiliary switch can be turned on and the main switch can be turned off to transfer the magnetizing energy stored in the inductor and the energy stored in the first capacitor to the second capacitor. After the energy stored in the inductor is dissipated, the second capacitor charges the inductor and the first capacitor to reverse the magnetic field in the inductor so as to reset the transformer.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: June 1, 2004
    Assignee: Ambit Microsystems Corp.
    Inventor: Guo-Kiang Hung
  • Patent number: 6700801
    Abstract: A switching power supply capable of translating a.c. voltage of sinusoidal waveform into d.c. voltage, having a rectifier circuit connected to a pair of a.c. input terminals for rectifying the incoming commercial a.c. voltage. A first main switch is connected between the pair of outputs of the rectifier circuit via a main inductor. A smoothing capacitor is connected in parallel with the first main switch via a rectifying diode. A second main switch is connected in parallel with the smoothing capacitor via the primary winding of a transformer. The first and the second main switch are each provided with a soft-switching capacitor connected in parallel therewith. A first and a second ancillary inductor, electromagnetically coupled respectively to the main inductor and to the transformer primary, are connected in parallel with the first and the second soft-switching capacitor via a first and a second ancillary switch, respectively.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: March 2, 2004
    Assignee: Sanken Electric Co., Ltd.
    Inventors: Koichi Morita, Toshiyuki Yamagishi
  • Patent number: 6583997
    Abstract: A wide input range switching power supply for a circuit protection device includes a rectifier circuit for rectifying an AC line voltage at a supply input, and a switch-mode DC-to-DC converter coupled to the rectifier circuit for providing a low voltage DC power to a load at a supply output. The converter includes a switch having an open state and a closed state and a control circuit for controlling the state of the switch. The control circuit is operatively coupled to receive operating power from the supply output.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: June 24, 2003
    Assignee: Square D Company
    Inventors: Paul A. Reid, Randall J. Gass
  • Patent number: 6498735
    Abstract: A switching power supply unit includes first and second switching circuits which alternately turn first and second switching elements on and off with an intermediate period in which both are turned off, and energy is stored in a primary winding of a transformer during an ON period of the first switching element and the energy is discharged from a secondary winding of the transformer during an OFF period of the first switching element. A control circuit includes an OFF period extending circuit connected to a control terminal of the first switching element, such that a transistor remains turned on for a desired period even after the energy has been discharged from the secondary winding, extending the OFF period of the first switching element for the desired period. In a light load operation, a phototransistor in the second control circuit is turned on so that the ON period of the second switching element will be shorter than the time required to discharge the energy from the secondary winding.
    Type: Grant
    Filed: December 19, 2001
    Date of Patent: December 24, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tatsuya Hosotani, Hiroshi Takemura
  • Patent number: 6466460
    Abstract: A high efficiency power converter for generating a high voltage from a low voltage supply. The power converter includes a resonant circuit in electrical communication with the low voltage supply via a switch. The power converter further includes a control circuit in electrical communication with the switch and a resonant inductor of the resonant circuit. The control circuit is operative to open and close the switch in response to the current flowing through the resonant inductor. A transformer is connected parallel to the resonant inductor and is operative to generate the high output voltage from the voltage of the resonant inductor. In the preferred embodiment, the switch is closed at the point in time when the current in the resonant inductor passes zero. At this time, switching conditions within the switch are ideal such that any losses experienced by the switch are conduction losses thereby resulting in improved efficiency of the power converter.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: October 15, 2002
    Assignee: Northrop Grumman Corporation
    Inventors: John M. Rein, Jeffrey C. Perkins
  • Patent number: 6434023
    Abstract: In order to achieve complete short-circuit protection irrespective of a location of a short-circuit in a switched-mode power supply having a controllable switch in a primary circuit, the controllable switch is opened when a voltage drop across an electrolytic capacitor in a primary circuit falls below a threshold value which can be predetermined. For this purpose, a capacitive voltage device containing two capacitances is connected in parallel with the electrolytic capacitor. A potential at a center tap of the capacitive voltage divider is compared in a comparator with a reference voltage, which opens the controllable switch when the potential at the center tap falls below the reference voltage.
    Type: Grant
    Filed: January 17, 2001
    Date of Patent: August 13, 2002
    Assignee: Infineon Technologies AG
    Inventor: Peter Preller
  • Patent number: 6426886
    Abstract: A generic voltage converter outputs at least two voltages: a Vo potential that is regulated using output-to-input feedback to a PWM that controls duty cycle of the converter switch, and a VoAUX potential available from a post-linear regulator. Output-to-input feedback is provided from the post-linear regulator to a node in the PWM, e.g., COMP, SoftStart, VFB. Whenever the post-linear regulator senses excessive VoAUX current, feedback from the regulator commands the PWM to reduce converter duty cycle, which reduces VinAUX, as well as VoAUX and Vo, without cross-regulation. The topology minimizes thermal dissipation within the regulator pass element by saturating the pass element at maximum VoAUX current flow such that at maximum current flow there is minimal voltage drop across the pass element.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: July 30, 2002
    Assignee: Switch Power, Inc.
    Inventor: Dimitry Goder
  • Patent number: 6414861
    Abstract: A DC-DC converter having a switching element and a synchronous rectifier, the switching element undergoing a switching operation, the converter performing a voltage conversion of an input voltage to provide a converted output voltage at an output/input conversion ratio that is determined by the switching operation of said switching element, the converter delivering the converted output voltage to a load, said DC-DC converter further comprising: a reverse current detector for detecting a reverse current which flows from an output of the converter to an input of the converter, and a reverse current suppressor, the reverse current suppressor controlling the switching operation of said switching element so as to increase the output/input conversion ratio when a reverse current is detected by the reverse current detector, thereby suppressing the reverse current.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: July 2, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tadahiko Matsumoto, Jun Nagai, Takayoshi Nishiyama, Hitoshi Tsuji
  • Patent number: 6377481
    Abstract: Diode recovery current suppression circuits are disclosed for use with power supplies. A power supply circuit including the diode recovery current suppression circuit may include a main inductor and a main diode coupled to the end of the main inductor. In such a context, the diode recovery current suppression circuit can include (a) a set of additional inductive windings, (b) an auxiliary inductor, and (c) an auxiliary diode. The set of additional inductive windings are coupled to the end of the main inductor such that the diode recovery current suppression circuit is coupled in parallel with the main diode.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: April 23, 2002
    Assignee: Peco II, Inc.
    Inventor: Gueorgui I. Mantov
  • Patent number: 6313976
    Abstract: A power supply controller having a multi-function terminal. In one embodiment, a power supply controller for switched mode power supply includes a drain terminal, a source terminal, a control terminal and a multi-function terminal. The multi-function terminal may be configured in a plurality of ways providing any one or some of a plurality of functions including on/off control, external current limit adjustments, under-voltage detection, over-voltage detection and maximum duty cycle adjustment. The operation of the multi-function terminal varies depending on whether a positive or negative current flows through the multi-function terminal. A short-circuit to ground from the multi-function terminal enables the power supply controller. A short-circuit to a supply voltage from the multi-function terminal disables the power supply controller. The current limit of an internal power switch of the power supply controller may be adjusted by externally setting a negative current from the multi-function terminal.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: November 6, 2001
    Assignee: Power Integrations, Inc.
    Inventors: Balu Balakrishnan, Alex B. Djenguerian, Leif O. Lund