Fisher Controls International LLC

Fisher Controls LLC.

George Wayne Gassman

Stephen George Seberger

Douglas Paul Gethmann

Bruce Frederick Grumstrup

Warren G Buchwald

Nate F Scarpelli

Ronald Francis Hurd

Carl Gene Scafferi

Curt Galbreath

Gerald F Varnum

A digital positioner for a valve includes a valve controller configured to obtain a set point value for a valve travel of a valve, and generate a pulse-width modulated current signal based on the set point value. The digital positioner also includes a current-to-pressure converter configured to receive the pulse-width modulated current signal from the valve controller, convert the pulse-width modulated current signal to a pulse-width modulated pressure signal, and provide the pulse-width modulated pressure signal to a pneumatic actuator in the valve to adjust a position of the valve.

Feature set and methods for a digital positioner

An electropneumatic switch valve includes a pneumatic circuit to a pressurized fluid source, an electromagnetic circuit coupled to the pneumatic circuit, and a control module connected to the electromagnetic circuit. The control module provides a first control signal inducing a first state of the pneumatic circuit, a second control signal inducing a second state of the pneumatic circuit, a third control signal inducing a third state of the pneumatic circuit, and a fourth control signal inducing a fourth state of the pneumatic circuit.

Integrated transducer

A transducer with a lower housing assembly and an upper housing assembly is for connection to a fluid pressure source having a mechanism for setting a pneumatic output via an electrical input signal. The lower housing assembly comprises lower housing configured to receive a supply nozzle, which fluidly communicates with a supply port and intermittently fluidly communicates with an output port of the lower housing through an internal fluid passageway. The lower housing further comprises an exhaust nozzle fluidly communicating with an exhaust port and intermittently fluidly communicates with the output port of the lower housing through the internal fluid passageway. The upper housing assembly comprises an upper housing configured to receive a coil and an armature such that the upper housing, coil and armature define a latching electromagnetic circuit that provides alternating contact of the armature with the supply nozzle and the exhaust nozzle of the lower housing assembly.

Failsafe integrated transducer

A transducer for a connection to a fluid pressure source having a mechanism for setting a pneumatic output by way of an electrical input signal. The transducer provides a lower housing assembly and an upper housing assembly. The lower housing assembly comprises lower housing configured to receive a supply nozzle. The supply nozzle fluidly communicates with a supply port and intermittently fluidly communicates with an output port of the lower housing through an internal fluid passageway. The lower housing further comprises an exhaust nozzle fluidly communicating with an exhaust port and intermittently fluidly communicates with the output port of the lower housing through the internal fluid passageway. The upper housing assembly comprises an upper housing configured to receive a coil and an armature such that the upper housing, coil and armature define a latching electromagnetic circuit that provides alternating contact of the armature with the supply nozzle and the exhaust nozzle of the lower housing assembly.

A non-contacting position sensor detects relative displacement between two objects. A magnetic flux source is provided by a plurality of discrete magnets selectively determined to produce a highly configurable flux source that is easily adapted to rotary or rectilinear displacement. The interaction of the individual flux fields generated by the discrete magnets is controlled to produce both linear and non-linear relationships with respect to changes in displacement. A flux-gathering pole piece is dimensionally optimized to integrate the plurality of individual flux fields directed to a magnetic sensor.

Position sensor using a compound magnetic flux source

A control system for positioning a control valve is disclosed. The control system employs first and second control loops, and a plug and seat valve assembly. The first control loop monitors a position or variable of the valve or device being controlled and compares it to a provided setpoint to generate a setpoint for the plug and seat valve. The second control loop compares the measured position of the plug and seat valve to the second setpoint to generate a correction signal to accurately position the plug and seat valve. By employing first and second control loops, the accuracy and responsiveness to which the control valve is positioned is improved.

Plug and seat positioning system for control applications

A temperature compensation method for a microprocessor based electro-pneumatic converter device including an initial calibration sequence, a compensation sequence, and an operation sequence. Linearization of an electro-pneumatic positioner including the steps of adjusting the positioner feedback linkage until a predetermined reference position is attained, reading a position feedback value and determining the required feedback linearization value to achieve a linear relationship between the output/input. A calibration method and a configuration method independent of calibration for a microprocessor based electro-pneumatic converter device including an initial calibration sequence, a configuration sequence, and an operation sequence.

Electro-pneumatic converter calibration

The present invention relates to a circuit which is connected by two conductors to a control system for a variable analog DC input and that also enables bidirectional digital communication along the two conductors for diagnostic operations of an instrument. The novel circuit includes a switch circuit that has a first position that provided the ability to accept both the variable DC analog signals and the bidirectional digital communication signals by presenting a first impedance for the DC signals and a second switch position for providing a second substantially higher impedance while using the same two conductor system. The novel invention also includes an auxiliary analog input signal to the circuit which allows further control as a current feedback to a control algorithm in a microcontroller. An auxiliary process transmitter can sense pressure, temperature, flow or some other process related variable and couple it to the circuit for control of the instrument. Finally, the novel invention includes a novel voltage regulator and a capacitive voltage supply for utilizing the voltage on the two conductors from the controller to also power the device.

Communication system and method

Apparatus responsive to a control signal for developing a pressure includes a current-to-pressure transducer including a transducer responsive to the control signal for developing the pressure and a filter disposed intermediate the control signal and the current-to-pressure transducer. The filter has a dynamic input-to-output characteristic with an adjustable time constant so that the dynamic input-to-output characteristic can be varied. The apparatus also includes a signal selector for selectively activating and deactivating the filter.

Current-to-pressure transducer with selectable, adjustable input filter

The present invention relates to a circuit which is connected by two-conductors to a control system for a variable analog DC input and that also enables bidirectional digital communication along the two conductors for diagnostic operations of an instrument. The novel circuit includes a switch circuit that has a first position that provided the ability to accept both the variable DC analog signals and the bidirectional digital communication signals by presenting a first impedance for the DC signals and a second switch position for providing a second substantially higher impedance while using the same two-conductor system. The novel invention also includes an auxiliary analog input signal to the circuit which allows further control as a current feedback to a control algorithm in a microcontroller. An auxiliary process transmitter can sense pressure, temperature, flow or some other process related variable and couple it to the circuit for control of the instrument. Finally, the novel invention includes a novel voltage regulator and a capacitive voltage supply for utilizing the voltage on the two conductors from the controller to also power the device.

A mechanical flexure element useful for motion amplification with a closed end and two legs extending therefrom in a general U-shaped configuration. One leg may be fixed and the other leg moved, or both legs may be movable with respect to each other. Microdisplacements of a leg are amplified and translated into larger transverse movements of the closed end. Reversing the input and output displacements provides attenuation of a larger input displacement. A magnetostrictive electromechanical transducer with a flexure element having a closed end and two legs extending thereform moving towards and away from a nozzle in an enclosed nozzle chamber under fluid pressure. An electrical input signal actuates a magnetostrictive element coupled to one leg of the flexure element to move the element with respect to the nozzle thereby changing the fluid output pressure from the nozzle chamber. Diaphragm means are coupled to the moving leg of the flexure element and responsive to the changing pressure in the nozzle chamber to provide a feedback force until the final fluid output pressure is proportional to the electrical input signal.

Growing community of inventors

Marshalltown, IA, United States of America

George Wayne Gassman