Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A pneumatic controller for controlling a process advantageously reduces fluid consumption by providing a proportional adjustment to a feedback signal. The pneumatic controller comprises a pneumatic control stage, a process pressure detector, and a feedback proportioning device. The feedback proportioning device uses a feedback cantilever component to provide the proportional adjustment of the feedback signal, thereby reducing the fluid consumption of the pneumatic controller.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.