Patents by Inventor Toshihisa Shimizu

Toshihisa Shimizu 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).

  • Quasi-resonant PWM inverter
    Patent number: 5572418
    Abstract: A quasi-resonant PWM inverter performs stable resonant operation utilizing a simple control system and a highly efficient inverter operation. A first condenser is connected between a connecting point between first and second main switches and to the first side of the first main switch. A second condenser is connected between the connecting point and the second side of the second main switch. The respective first and second sides of the first main switch and second main switch are connected to a DC power source having a first dividing point for the first potential and a second dividing point for the second potential. A terminal of a first auxiliary switch is connected to the first dividing point; and a terminal of a second auxiliary switch is connected to the second dividing point. A reactor is connected between the connecting points of the first and second auxiliary switches and the first and second main switches.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: November 5, 1996
    Assignee: Yuasa Corporation
    Inventors: Gunji Kimura, Toshihisa Shimizu, Akio Toba, Shigeru Sano
  • Transistor module having external lead terminal with transient voltage suppression
    Patent number: 5306949
    Abstract: In an external lead terminal 5 of a transistor module, an intermediate terminal portion 6 and an external lead terminal 8 are conductively connected to each other via a U-shaped intermediate terminal portion 7 having a curved portion 7b. Connected in parallel with this intermediate terminal portion 7 is a shortcircuit wire 9 having a larger electric resistance and a smaller inductance than the same. For this reason, even if a current is reduced suddenly in a state in which the current is flowing from the external terminal portion 8 to the intermediate terminal portion 6 via the intermediate terminal portion 7, the current shifts to the shortcircuit wire 9 side, so that a transient voltage is low. Consequently, it is provided a transistor module capable of reducing a transient voltage without being subjected to restrictions in the size of an external lead terminal while maintaining a high level of reliability.
    Type: Grant
    Filed: November 9, 1992
    Date of Patent: April 26, 1994
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Toshifusa Yamada, Shuji Miyashita, Toshihisa Shimizu
  • System disconnection detection circuit for a distributed location power source
    Patent number: 5099145
    Abstract: A system disconnection detection circuit for a distributed location power source having a generating element and an invertor for converting a generated output from the generating element into an AC output superimposes a selected signal on the AC output of the invertor. The circuit detects system disconnection on the output side of the invertor on the basis of the AC output of the invertor on which the selected signal has been superimposed.
    Type: Grant
    Filed: October 23, 1990
    Date of Patent: March 24, 1992
    Assignees: Fuji Electric Co., Ltd., Shikoku Research Institute Incorporated
    Inventors: Hiromasa Higasa, Fumihiko Ishikawa, Shigenori Matsumura, Takeshi Takemura, Toshihisa Shimizu