Patents by Inventor Eiji Takegami

Eiji Takegami has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20200313559
    Abstract: A power supply can be driven in parallel in a master-slave arrangement using fewer wires. Each power supply includes: input terminals; output terminals; a master terminal; a slave terminal; a switching power supply that switches an inputted voltage and executes one of a constant-voltage operation that outputs a DC voltage of a target voltage value and a constant-current operation that outputs a DC current of a target current value; an indicative voltage generator that generates a current detection signal indicating the current outputted from the output terminals, superimposes a bias voltage (>a threshold voltage), and outputs to the master terminal; and an operation switcher that compares a voltage applied to the slave terminal and the threshold voltage and outputs, based on the result, a control signal for switching to the constant-voltage operation or the constant-current operation, to the switching power supply.
    Type: Application
    Filed: March 18, 2020
    Publication date: October 1, 2020
    Applicant: TDK CORPORATION
    Inventor: Eiji TAKEGAMI
  • Publication number: 20200313545
    Abstract: A power supply includes: a power factor correction circuit that includes a capacitor and converts an input voltage, produced by rectifying an AC input voltage, to a DC, output voltage; a current detector that detects an inflow current for the power factor correction circuit and outputs a current detection signal; an output voltage detector that detects the output voltage and outputs an output voltage detection signal; a voltage difference detector that detects a voltage difference between maximum and minimum values of a pulsation component of the output voltage detected from the output voltage detection signal; a working life determiner that compares the voltage difference and a threshold and gives notification of end of life of the capacitor when the voltage difference reaches the threshold; and a threshold updater that updates the threshold in keeping with the detected inflow current detected based on the current detection signal.
    Type: Application
    Filed: March 17, 2020
    Publication date: October 1, 2020
    Applicant: TDK CORPORATION
    Inventor: Eiji TAKEGAMI
  • Publication number: 20200295667
    Abstract: A power supply includes a synchronous rectification-type rectifying/smoothing circuit to increase the conversion efficiency of an output voltage, avoids cost increases, and can change the output voltage and maximum output current. The power supply includes synchronous rectifiers connected to secondary windings of a transformer, smoothing circuits that smooth a voltage outputted from the synchronous rectifiers to produce an output voltage, switch drivers that correspond to the synchronous rectifiers and operate on one or both of the output voltage outputted from the smoothing circuits connected to the synchronous rectifiers and an AC voltage generated in the secondary windings to drive synchronous rectification switches of the synchronous rectifiers, and an output connector that is disposed following the smoothing circuits and connects the outputs of the smoothing circuits in a connection pattern selected out of serial and parallel.
    Type: Application
    Filed: March 5, 2020
    Publication date: September 17, 2020
    Applicant: TDK CORPORATION
    Inventor: Eiji TAKEGAMI
  • Patent number: 10454374
    Abstract: A power supply includes: a power converter that converts an input voltage by switching at a switch and supplies an output voltage and an output current to an output terminal connected to a load; a current detector that detects the output current or a current that changes with the output current and outputs a current detection signal whose voltage value changes with the output current; a signal corrector that inputs and corrects the current detection signal and generates and outputs a corrected current detection signal whose voltage value corresponds to the value of the output current; a matching circuit that inputs the corrected current detection signal and outputs to a balanced terminal; and a controller that inputs the corrected current detection signal and a balanced voltage signal generated at the balanced terminal and controls switching operations of the switch to reduce a difference between the two signals.
    Type: Grant
    Filed: September 20, 2018
    Date of Patent: October 22, 2019
    Assignee: TDK CORPORATION
    Inventors: Eiji Takegami, Tomokazu Ikarashi
  • Publication number: 20190149048
    Abstract: A power supply includes: a power converter that converts an input voltage by switching at a switch and supplies an output voltage and an output current to an output terminal connected to a load; a current detector that detects the output current or a current that changes with the output current and outputs a current detection signal whose voltage value changes with the output current; a signal corrector that inputs and corrects the current detection signal and generates and outputs a corrected current detection signal whose voltage value corresponds to the value of the output current; a matching circuit that inputs the corrected current detection signal and outputs to a balanced terminal; and a controller that inputs the corrected current detection signal and a balanced voltage signal generated at the balanced terminal and controls switching operations of the switch to reduce a difference between the two signals.
    Type: Application
    Filed: September 20, 2018
    Publication date: May 16, 2019
    Applicant: TDK CORPORATION
    Inventors: Eiji TAKEGAMI, Tomokazu IKARASHI
  • Patent number: 9899927
    Abstract: A control device and method are provided for a power supply device which can perform stable constant voltage constant current control with high responsiveness with a simple configuration. The control device includes: a voltage difference value generation unit which subtracts an output voltage value from a voltage target value to generate a voltage difference value; a current difference value generation unit which subtracts an output current value from a current target value to generate a current difference value; a difference value selection unit which compares the voltage difference value or a value based on the voltage difference value with the current difference value or a value based on the current difference value, and selects the smaller one as a control difference value; and an operation amount generation unit which generates an operation amount for controlling the power supply device based on the control difference value.
    Type: Grant
    Filed: July 1, 2016
    Date of Patent: February 20, 2018
    Assignee: TDK Corporation
    Inventor: Eiji Takegami
  • Publication number: 20170005582
    Abstract: A control device and method are provided for a power supply device which can perform stable constant voltage constant current control with high responsiveness with a simple configuration. The control device includes: a voltage difference value generation unit which subtracts an output voltage value from a voltage target value to generate a voltage difference value; a current difference value generation unit which subtracts an output current value from a current target value to generate a current difference value; a difference value selection unit which compares the voltage difference value or a value based on the voltage difference value with the current difference value or a value based on the current difference value, and selects the smaller one as a control difference value; and an operation amount generation unit which generates an operation amount for controlling the power supply device based on the control difference value.
    Type: Application
    Filed: July 1, 2016
    Publication date: January 5, 2017
    Inventor: Eiji TAKEGAMI
  • Patent number: 9093908
    Abstract: A bidirectional DC-DC converter is configured with a transformer that has a first winding and a second winding, a first DC-AC converter that is provided between a first DC voltage line and the first winding, a second DC-AC converter that is provided between a second DC voltage line and the second winding, and a controller that performs a switching control operation that bidirectionally transmits DC power between the first DC voltage line and the second DC voltage line. When the bidirectional DC-DC converter is in a light load operation state, the controller provides an operation stop period that periodically stops the switching control operation so as to perform an intermittent switching control operation.
    Type: Grant
    Filed: May 31, 2013
    Date of Patent: July 28, 2015
    Assignee: TDK Corporation
    Inventor: Eiji Takegami
  • Patent number: 8929098
    Abstract: A controller controls a voltage-source power converter and a current-source power converter based on a detection value of a rail voltage input to the voltage-source power converter and a detection value of a charging voltage output from the current-source power converter, at the time of charging operation.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: January 6, 2015
    Assignee: TDK-Lambda Corporation
    Inventor: Eiji Takegami
  • Patent number: 8885370
    Abstract: A current-fed isolation converter includes a coil that is connected to a primary side of a transformer, a power source that supplies electric power to the primary side of the transformer, a switching element that controls a first electric current flowing in the coil, a snubber circuit that includes a rectifying element and a capacitive element that is charged by a second electric current flowing in the rectifying element, and a step-down power supply circuit that regenerates electric charge of the capacitive element to the power source. The snubber circuit controls an excess voltage that is generated when the switching element is turned off. The power supply circuit maintains a charging voltage of the capacitive element at a predetermined voltage value.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: November 11, 2014
    Assignee: TDK Corporation
    Inventor: Eiji Takegami
  • Patent number: 8842446
    Abstract: A controller controls a voltage-source power converter and a current-source power converter based on a detection value of a rail voltage input to the voltage-source power converter and a detection value of a charging voltage output from the current-source power converter, at the time of charging operation.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: September 23, 2014
    Assignee: TDK-Lambda Corporation
    Inventor: Eiji Takegami
  • Patent number: 8830701
    Abstract: A DC-DC converter is configured with a voltage-source power converter at a primary side of a transformer, a current-source power converter at a secondary side of the transformer, and a controller. The DC-DC converter is connected between a storage battery and an inverter that drives an electric motor. The controller generates a first control input based on a voltage between input and output terminals of the voltage-source power converter, a second control input based on a voltage between input and output terminals of the current-source power converter, and a command value for PWM or PFM control based on the first and second control inputs and an input-output current flowing between one of the input and output terminals of the voltage-source power converter and the current-source power converter. Therefore, it is easy to switch between a powering state and a regenerating state.
    Type: Grant
    Filed: November 27, 2012
    Date of Patent: September 9, 2014
    Assignee: TDK Corporation
    Inventor: Eiji Takegami
  • Patent number: 8830700
    Abstract: A DC-DC converter is configured with a voltage-source power converter provided at a primary side of a transformer, a current-source power converter provided at a secondary side of the transformer, and a controller. The controller generates a first control input based on a voltage between input and output terminals of the voltage-source power converter, a second control input based on a voltage between input and output terminals of the current-source power converter, and a command value for PWM or PFM control based on the first and second control inputs and an input-output current flowing between one of the input and output terminals of the voltage-source power converter and the current-source power converter. Therefore, it is easy to switch between a powering state and a regenerating state in the DC-DC converter.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: September 9, 2014
    Assignee: TDK Corporation
    Inventor: Eiji Takegami
  • Patent number: 8817490
    Abstract: A DC-DC converter is configured with a voltage-source power converter at a primary side of a transformer, a current-source power converter at a secondary side of the transformer, and a controller. First and second voltage detection circuits respectively detect first and second voltages of the voltage-source and the current-source power converters. A current detection circuit detects an input-output current of the current-source power converter. The controller controls the voltage-source and the current-source power converters to transfer power between the primary side and the secondary side of the transformer. The controller includes a calculation unit that performs calculations based on the first voltage, the second voltage and the input-output current, and a table unit that include a plurality of parameter sets. The calculation unit performs the calculations based on one of the plurality of parameter sets that is selected from the table unit.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: August 26, 2014
    Assignee: TDK Corporation
    Inventors: Eiji Takegami, Jun Kawakami, Takeshi Kamono
  • Publication number: 20140211515
    Abstract: A DC-DC converter is configured with a step-down converter that outputs a output voltage having the same voltage value as an input voltage when a step-down operation stops and that outputs the first output voltage having a lower voltage value than the input voltage when the step-down operation is performed, and a resonant converter in which a voltage transfer factor is adjusted by a switching frequency of a switching element through which a resonance current flows. A step-down operation of the step-down converter is performed when the switching frequency, the voltage transfer factor and a target value for the output voltage satisfy a predetermined condition. According to the above configuration, it is possible to decrease switching loss of the step-down converter.
    Type: Application
    Filed: January 23, 2014
    Publication date: July 31, 2014
    Applicant: TDK Corporation
    Inventors: Satoshi TOMIOKA, Eiji TAKEGAMI
  • Publication number: 20130322128
    Abstract: A bidirectional DC-DC converter is configured with a transformer that has a first winding and a second winding, a first DC-AC converter that is provided between a first DC voltage line and the first winding, a second DC-AC converter that is provided between a second DC voltage line and the second winding, and a controller that performs a switching control operation that bidirectionally transmits DC power between the first DC voltage line and the second DC voltage line. When the bidirectional DC-DC converter is in a light load operation state, the controller provides an operation stop period that periodically stops the switching control operation so as to perform an intermittent switching control operation.
    Type: Application
    Filed: May 31, 2013
    Publication date: December 5, 2013
    Inventor: Eiji TAKEGAMI
  • Publication number: 20130027984
    Abstract: A current-fed isolation converter includes a coil that is connected to a primary side of a transformer, a power source that supplies electric power to the primary side of the transformer, a switching element that controls a first electric current flowing in the coil, a snubber circuit that includes a rectifying element and a capacitive element that is charged by a second electric current flowing in the rectifying element, and a step-down power supply circuit that regenerates electric charge of the capacitive element to the power source. The snubber circuit controls an excess voltage that is generated when the switching element is turned off. The power supply circuit maintains a charging voltage of the capacitive element at a predetermined voltage value.
    Type: Application
    Filed: July 26, 2012
    Publication date: January 31, 2013
    Applicant: TDK CORPORATION
    Inventor: Eiji TAKEGAMI
  • Patent number: 8285400
    Abstract: There is provided a digital controller which can reduce a variation in output voltage as compared to the conventional digital controller at the time of abrupt changes in load and in input of a power amplifier. The digital controller is built in the power amplifier for supplying an output voltage vo to a load and is equipped with a manipulated variable calculating unit which detects the output voltage vo to calculate a manipulated variable ?1 and a signal generating unit which converts the manipulated variable ?1 into a signal for making the power amplifier operate. A feedforward function from an equivalent disturbance qy caused by the variation in the load is replaced by a feedback function from the output voltage vo and the manipulated variable ?1, thereby allowing a transfer characteristic from the disturbance qy to the output voltage vo to result in a quadratic differential characteristic.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: October 9, 2012
    Assignee: TDK-Lambda Corporation
    Inventors: Kouji Higuchi, Kazushi Nakano, Tatsuyoshi Kajikawa, Eiji Takegami, Kazushi Watanabe, Satoshi Tomioka
  • Patent number: 8099199
    Abstract: There is provided a digital controller which can generate no oscillation even if sensing a load side and enables control of supplying a desired voltage to the load. In an power amplifier which supplies an output voltage vo to the load connected via a load connecting line, a load voltage vL and the output voltage vo are periodically sampled to calculate a manipulating variable ?1 from the output voltage vo, the load voltage vL and an arbitrary target value r. Based on the manipulating variable ?1 calculated, a control signal is output to the power amplifier. As a result, when connecting an LC filter with a load device 9 of the power amplifier intended for a control target and besides the load connecting line is long, a robust digital controller without generating oscillation even if sensing the load side is performed can be realized.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: January 17, 2012
    Assignee: TDK-Lameda Corporation
    Inventors: Eiji Takegami, Kazushi Watanabe, Satoshi Tomioka, Kouji Higuchi, Kazushi Nakano, Tatsuyoshi Kajikawa
  • Publication number: 20110310637
    Abstract: A controller controls a voltage-source power converter and a current-source power converter based on a detection value of a rail voltage input to the voltage-source power converter and a detection value of a charging voltage output from the current-source power converter, at the time of charging operation.
    Type: Application
    Filed: June 13, 2011
    Publication date: December 22, 2011
    Applicant: TDK-LAMBDA CORPORATION
    Inventor: Eiji TAKEGAMI