Patents by Inventor Sadahiro Akama

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

  • Patent number: 11183933
    Abstract: A control device has a first control part and a second control part. The control device is applied to a DC-DC converter. The control device selects a first switch turning-on instruction or a first switch turning-off instruction generated by the first control part during a voltage boost control period, and transmits the selected first switch turning-on instruction or the selected first switch turning-off instruction to a first switch in the DC-DC converter. The control device selects a second switch turning-on instruction or a second switch turning-off instruction generated by the second control part during a voltage step-down control period, and transmits the selected second switch turning-on instruction or the selected second switch turning-off instruction to a second switch in the DC-DC converter.
    Type: Grant
    Filed: January 16, 2020
    Date of Patent: November 23, 2021
    Assignee: DENSO CORPORATION
    Inventors: Mitsutaka Ito, Sadahiro Akama
  • Publication number: 20200235665
    Abstract: A control device has a first control part and a second control part. The control device is applied to a DC-DC converter. The control device selects a first switch turning-on instruction or a first switch turning-off instruction generated by the first control part during a voltage boost control period, and transmits the selected first switch turning-on instruction or the selected first switch turning-off instruction to a first switch in the DC-DC converter. The control device selects a second switch turning-on instruction or a second switch turning-off instruction generated by the second control part during a voltage step-down control period, and transmits the selected second switch turning-on instruction or the selected second switch turning-off instruction to a second switch in the DC-DC converter.
    Type: Application
    Filed: January 16, 2020
    Publication date: July 23, 2020
    Applicant: DENSO CORPORATION
    Inventors: Mitsutaka ITO, Sadahiro AKAMA
  • Publication number: 20190113563
    Abstract: A semiconductor device includes a main switching element, a sense switching element, a sense resistor and an operational amplifier. The main switching element has a first terminal and a second terminal between which a load current flows. The sense switching element is connected to the main switching element to form a current mirror, and has a third terminal and a fourth terminal between which a sense current correlated with the load current flows. The sense resistor is arranged in a feedback path of the operational amplifier. A direction of the sense current flowing through the sense resistor is switchable according to a magnitude relationship between a potential of the first terminal and a potential of the second terminal or a magnitude relationship between the potential of the first terminal and the potential of the fourth terminal.
    Type: Application
    Filed: December 21, 2018
    Publication date: April 18, 2019
    Inventors: Sadahiro AKAMA, Hidekazu ONO
  • Patent number: 9979384
    Abstract: A timing adjustment method for a drive circuit, including: a rise detector for a rise start when a voltage-driven semiconductor element is turned off; a timing signal output unit outputting a speed change timing signal after a set delay time has elapsed from the rise start; and a conduction controller for a conduction control terminal of the semiconductor element using the timing signal, comprises: defining an estimated terminal voltage of the conduction control terminal when a rise completion time elapses; increasing a delay time by a predetermined unit time, and changing the drive signal to a turning off level again, when the conduction control terminal doesn't fall below the estimated terminal voltage after the drive signal is changed to a turning off level before the level is inverted; and determining a delay time, when the conduction control terminal falls below the estimated terminal voltage initially, as a set value.
    Type: Grant
    Filed: April 2, 2015
    Date of Patent: May 22, 2018
    Assignee: DENSO CORPORATION
    Inventors: Atsushi Kobayashi, Kiyoshi Yamamoto, Atsushi Kanamori, Sadahiro Akama
  • Patent number: 9900000
    Abstract: A drive device for controlling a power switching element to turn on and off includes: an on-side circuit performing an on operation of the power switching element; an off-side circuit performing an off operation of the power switching element; and a temperature detector detecting a temperature. At least one of the on-side and off-side circuits includes a current path for supplying or drawing a gate current of the power switching element and a switch circuit for switching the gate current. The switch circuit transitionally changes the gate current based on the temperature of the power switching element when the switching circuit switches the gate current.
    Type: Grant
    Filed: March 12, 2015
    Date of Patent: February 20, 2018
    Assignee: DENSO CORPORATION
    Inventors: Atsushi Kanamori, Sadahiro Akama, Kiyoshi Yamamoto, Atsushi Kobayashi
  • Patent number: 9800237
    Abstract: A drive device for controlling a power switching element includes: an on-side circuit that performs an on operation of the power switching element; and an off-side circuit that performs an off operation of the power switching element. The on-side circuit or the off-side circuit includes: multiple main MOS transistors; a sense MOS transistor that define a drain current of each main MOS transistor; and a sense current control circuit that controls a drain current of the sense MOS transistor to be constant; and a switch circuit that is connected to the gate of each main MOS transistor, and controls each main MOS transistor to turn on and off so as to switch a gate current in the power switching element.
    Type: Grant
    Filed: March 12, 2015
    Date of Patent: October 24, 2017
    Assignee: DENSO CORPORATION
    Inventors: Sadahiro Akama, Kiyoshi Yamamoto, Atsushi Kobayashi, Atsushi Kanamori
  • Publication number: 20170104479
    Abstract: A drive device for controlling a power switching element to turn on and off includes: an on-side circuit performing an on operation of the power switching element; an off-side circuit performing an off operation of the power switching element; and a temperature detector detecting a temperature. At least one of the on-side and off-side circuits includes a current path for supplying or drawing a gate current of the power switching element and a switch circuit for switching the gate current. The switch circuit transitionally changes the gate current based on the temperature of the power switching element when the switching circuit switches the gate current.
    Type: Application
    Filed: March 12, 2015
    Publication date: April 13, 2017
    Inventors: Atsushi KANAMORI, Sadahiro AKAMA, Kiyoshi YAMAMOTO, Atsushi KOBAYASHI
  • Publication number: 20170093392
    Abstract: A timing adjustment method for a drive circuit, including: a rise detector for a rise start when a voltage-driven semiconductor element is turned off; a timing signal output unit outputting a speed change timing signal after a set delay time has elapsed from the rise start; and a conduction controller for a conduction control terminal of the semiconductor element using the timing signal, comprises: defining an estimated terminal voltage of the conduction control terminal when a rise completion time elapses; increasing a delay time by a predetermined unit time, and changing the drive signal to a turning off level again, when the conduction control terminal doesn't fall below the estimated terminal voltage after the drive signal is changed to a turning off level before the level is inverted; and determining a delay time, when the conduction control terminal falls below the estimated terminal voltage initially, as a set value.
    Type: Application
    Filed: April 2, 2015
    Publication date: March 30, 2017
    Inventors: Atsushi KOBAYASHI, Kiyoshi YAMAMOTO, Atsushi KANAMORI, Sadahiro AKAMA
  • Publication number: 20160352316
    Abstract: A drive device for controlling a power switching element includes: an on-side circuit that performs an on operation of the power switching element; and an off-side circuit that performs an off operation of the power switching element. The on-side circuit or the off-side circuit includes: multiple main MOS transistors; a sense MOS transistor that define a drain current of each main MOS transistor; and a sense current control circuit that controls a drain current of the sense MOS transistor to be constant; and a switch circuit that is connected to the gate of each main MOS transistor, and controls each main MOS transistor to turn on and off so as to switch a gate current in the power switching element.
    Type: Application
    Filed: March 12, 2015
    Publication date: December 1, 2016
    Inventors: Sadahiro AKAMA, Kiyoshi YAMAMOTO, Atsushi KOBAYASHI, Atsushi KANAMORI
  • Patent number: 8593092
    Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.
    Type: Grant
    Filed: February 6, 2013
    Date of Patent: November 26, 2013
    Assignee: DENSO CORPORATION
    Inventors: Masahiro Kuroda, Nobumasa Ueda, Kiyoshi Nagata, Masaya Ootake, Sadahiro Akama
  • Patent number: 8217603
    Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: July 10, 2012
    Assignee: DENSO CORPORATION
    Inventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
  • Patent number: 8179688
    Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.
    Type: Grant
    Filed: October 19, 2010
    Date of Patent: May 15, 2012
    Assignee: DENSO CORPORATION
    Inventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
  • Publication number: 20110080127
    Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.
    Type: Application
    Filed: November 24, 2010
    Publication date: April 7, 2011
    Applicant: DENSO CORPORATION
    Inventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
  • Publication number: 20110044009
    Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.
    Type: Application
    Filed: October 19, 2010
    Publication date: February 24, 2011
    Applicant: DENSO CORPORATION
    Inventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
  • Patent number: 7893638
    Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: February 22, 2011
    Assignee: DENSO CORPORATION
    Inventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
  • Patent number: 7843700
    Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: November 30, 2010
    Assignee: DENSO CORPORATION
    Inventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
  • Publication number: 20090174350
    Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.
    Type: Application
    Filed: December 16, 2008
    Publication date: July 9, 2009
    Applicant: DENSO CORPORATION
    Inventors: Masahiro Kuroda, Hiroshi Taki, Nobumasa Ueda, Sadahiro Akama, Kiyoshi Nagata, Masaya Ootake
  • Publication number: 20080252242
    Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.
    Type: Application
    Filed: October 31, 2007
    Publication date: October 16, 2008
    Applicant: DENSO CORPORATION
    Inventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
  • Publication number: 20050231925
    Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.
    Type: Application
    Filed: April 14, 2005
    Publication date: October 20, 2005
    Inventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi, Hiromasa Hayashi, Akihiro Fukatsu, Hirokazu Kasuya, Nobumasa Ueda