Title:
VALVE POSITIONER
Document Type and Number:
Japanese Patent JP3039267
Kind Code:
B2
Abstract:
PURPOSE: To eliminate an influence exercised by the noise of the drive part of a control valve to effect control and friction of a grand packing, to perform smooth operation, and to reduce an excessive amount and perform high speed response precise control.
CONSTITUTION: A valve positioner comprises a microprocessor 42 to compute a control signal MVk, by which at least proportional integrating operation is effected, from a set value signal SV from a master controller 1 and a feedback signal PV from a control valve 3; an electric/pneumatic converting part 44 to convert the control signal MVk into an analogue signal and an operation pneumatic signal 3B; and angle detecting parts 46 and 47 to convert a valve opening signal 3C from the control valve 3 into an angle signal 3D and perform feedback of a valve opening signal, being a digital signal, to the microprocessor 42. This constitution changes a control parameter by which proportional integrating operation is effected according to polarity of a control deviation consisting of a difference between the set value signal SV and the feedback signal PV.
Inventors:
Gunji Takumi
Application Number:
JP10145294A
Publication Date:
May 08, 2000
Filing Date:
May 17, 1994
Export Citation:
Assignee:
Fuji Electric Co., Ltd.
International Classes:
F16K31/04; F15B5/00; G05B11/36; (IPC1-7): F16K31/04; F15B5/00; G05B11/36
Attorney, Agent or Firm:
Masaharu Shinobe