Patents by Inventor Sadao Yanada

Sadao Yanada 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: 5214913
    Abstract: A method of and apparatus for controlling a triple-coil servo valve arranged having a tripled control system each of which is composed of components of a coil, a servo amplifier and a controller, the method of and the apparatus for controlling the triple servo valve including means for specifying the abnormality of each of the components, servo amplifier output separation means, means capable of desirably combining the components and means for compensating the servo amplifier. If two control systems of the tripled control system are faulty in such a manner that at least one coil, at least one servo amplifier or at least one controller is abnormal, the triple-coil servo is operated by combining the normal components or by compensating the servo amplifier so that the continuation of the operation of the plant is enabled.
    Type: Grant
    Filed: May 22, 1991
    Date of Patent: June 1, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Yukiyoshi Tani, Sadao Yanada, Takeshi Iwamiya, Takumi Kawai, Tadahiko Iijima
  • Patent number: 4825352
    Abstract: A process control system has a timer circuit which fixes operational periods by issuing an instruction for starting each of a plurality of time periods in such a manner that the computation of control blocks will occur during periods of fixed duration. A periodic operation selection circuit selects control blocks to be computed within each time period in response to an instruction from the timer circuit. Control blocks selected by the periodic operation selection circuit and an instruction for completion of the computation of control blocks for each time period are stacked in an operation instruction circuit, which issues an instruction for consecutively executing the operation of the control blocks and an instruction for effecting an idle operation after completion of the operation of control blocks for each time period.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: April 25, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tadahiko Iijima, Takumi Kawai, Yasuhiro Tennichi, Sadao Yanada
  • Patent number: 4558227
    Abstract: A method of controlling the operation of a thermoelectric power generating plant, in which the operation of the steam generating equipment and the turbine is controlled in accordance with the plant operation parameters obtained from given patterns of start up and operation of the plant.
    Type: Grant
    Filed: June 8, 1984
    Date of Patent: December 10, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Sadao Yanada, Naganobu Honda, Hisanori Miyagaki, Seiitsu Nigawara
  • Patent number: 4445169
    Abstract: A sequence display apparatus including a sequence control circuit, a cathode ray tube control device and a sequence display control device is disclosed in which a keyboard included in the sequence display control device is provided with logical function specifying keys for specifying one of a plurality of logical functions corresponding to such logical circuits as AND, OR and flip-flop circuits and a timer and with keys for inputting the names of input signals and the name of an output signal. One logic function, all of the names of the input signals and the name of the output signal are inputted as one set by the key-in operation, each of a group of command codes which are determined by the kind of logical function and the number of the names of input signals, is added to a corresponding one of the names of the input signals and the name of the output signal which have been inputted, to compose a logical operation program.
    Type: Grant
    Filed: June 12, 1981
    Date of Patent: April 24, 1984
    Assignees: The Tokyo Electric Co., Inc., Hitachi Engineering Ltd, Hitachi, Ltd.
    Inventors: Tadayoshi Wakita, Minoru Suzuki, Sadao Yanada, Sigeru Sibata