Patents by Inventor Takashi Funawatari

Takashi Funawatari 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: 6683769
    Abstract: Compatibility with a current transformer having several kinds of rated current ratios is achieved by finding out a formula of relationship between errors arising in a transformer input circuit and detectable ranges set as setting values of the input circuits which can be optimally set. In connection with that, by dispensing with a gain control section, the number of components, the mounting area and the cost can be reduced. Arithmetic expressions representing the relationship among errors arising in the transformer input circuit, the instrumentation ranges of the input circuits, and detectable errors have been derived. Further by optimally setting the detectable ranges of the input circuits, which are the parameters of the arithmetic expressions, the configuration compatible with a current transformer having several kinds of rated current ratios is achieved.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: January 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Maeda, Takashi Funawatari, Yoshiyasu Watanabe
  • Patent number: 6678136
    Abstract: Compatibility with a current transformer having several kinds of rated current ratios is achieved by finding out a formula of relationship between errors arising in a transformer input circuit and detectable ranges set as setting values of the input circuits which can be optimally set. In connection with that, by dispensing with a gain control section, the number of components, the mounting area and the cost can be reduced. Arithmetic expressions representing the relationship among errors arising in the transformer input circuit, the instrumentation ranges of the input circuits, and detectable errors have been derived. Further by optimally setting the detectable ranges of the input circuits, which are the parameters of the arithmetic expressions, the configuration compatible with a current transformer having several kinds of rated current ratios is achieved.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: January 13, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Maeda, Takashi Funawatari, Yoshiyasu Watanabe
  • Publication number: 20030072114
    Abstract: Compatibility with a current transformer having several kinds of rated current ratios is achieved by finding out a formula of relationship between errors arising in a transformer input circuit and detectable ranges set as setting values of the input circuits which can be optimally set. In connection with that, by dispensing with a gain control section, the number of components, the mounting area and the cost can be reduced. Arithmetic expressions representing the relationship among errors arising in the transformer input circuit, the instrumentation ranges of the input circuits, and detectable errors have been derived. Further by optimally setting the detectable ranges of the input circuits, which are the parameters of the arithmetic expressions, the configuration compatible with a current transformer having several kinds of rated current ratios is achieved.
    Type: Application
    Filed: September 20, 2002
    Publication date: April 17, 2003
    Applicant: Hitachi,Ltd.
    Inventors: Daisuke Maeda, Takashi Funawatari, Yoshiyasu Watanabe
  • Publication number: 20020159211
    Abstract: Compatibility with a current transformer having several kinds of rated current ratios is achieved by finding out a formula of relationship between errors arising in a transformer input circuit and detectable ranges set as setting values of the input circuits which can be optimally set. In connection with that, by dispensing with a gain control section, the number of components, the mounting area and the cost can be reduced. Arithmetic expressions representing the relationship among errors arising in the transformer input circuit, the instrumentation ranges of the input circuits, and detectable errors have been derived. Further by optimally setting the detectable ranges of the input circuits, which are the parameters of the arithmetic expressions, the configuration compatible with a current transformer having several kinds of rated current ratios is achieved.
    Type: Application
    Filed: August 31, 2001
    Publication date: October 31, 2002
    Inventors: Daisuke Maeda, Takashi Funawatari, Yoshiyasu Watanabe