Fisher Controls International LLC

Clyde Thomas Eisenbeis

Stephen George Seberger

Thomas Pesek

Brent Hans Larson

Jimmie Lee Snowbarger

Brian Joseph Burlage

Larry Keith Brown

Ross Schade

Carter Bill Cartwright

Riyaz M Ali

Scott Richard Kratzer

Steve A Packwood

Ronald L Uhlenberg

Ross Arthur Schade

Brian J Burlage

Scott R Kratzer

Brian Burlage

Methods and apparatus to diagnose a valve using electric valve actuators are disclosed. An example apparatus includes an electric motor to actuate a valve, rotation sensors to monitor a rotation of a drive shaft associated with the electric motor to determine a distance travelled by the drive shaft, and a valve position sensor to monitor a position of a flow control member of the valve. The example electric valve actuator further includes a processor to generate an alert based on feedback from the rotation sensors and the valve position sensor, the alert associated with a failure of the valve.

Methods and apparatus to diagnose a valve using electric valve actuators

A component in a process control device such as a valve actuator, for example, is coupled to a protective circuit. In particular, the protective circuit allows an analog current loop (e.g., 4-20 mA) to provide to the component a secondary operating voltage, derived from the analog current loop, in the absence of a primary operating voltage source (e.g., during a power failure), such that the component is not damaged when a signal from the analog current loop is applied to the process control device in the absence of the primary operating voltage source.

Current loop input protection

A protective circuit for a process control device such as a valve actuator, for example, prevents damage to device components. In particular, a protective circuit allows an analog current loop (e.g., 4-20 mA) to provide to a device component a secondary operating voltage, derived from the analog current loop, in the absence of a primary operating voltage source (e.g., during a power failure), such that the device component is not damaged when a signal from the analog current loop is applied to the process control device in the absence of the primary operating voltage source.

A system and method for monitoring and controlling the amount of electrical current provided to a motor used to actuate a field device within a control system.

Method and apparatus for monitoring motor current for an electric valve positioner

Multiple-contact switches are disclosed. An example multiple-contact switch disclosed herein includes a double throw switch having a common terminal, a first throw terminal, and a second throw terminal, the common terminal being coupled to a reference; a first throw circuit coupled to the first throw terminal, the first throw circuit to output an open signal to a process control device when the common terminal is substantially in contact with one of the first throw terminal or the second throw terminal; and a second throw circuit coupled to the second throw terminal, the second throw circuit to cause the first throw circuit to output a close signal to the process control device when the common terminal is substantially in contact with the other one of the first throw terminal or the second throw contact terminal, wherein at least one of the open signal or the close signal corresponds to the reference.

Multiple-contact switches

An opto-isolator multi-voltage detection circuit is capable to handle a wide range of input voltages ranging from about 9 volts DC to about 240 volts AC includes an input voltage, an opto-isolator, a rectifier, a voltage divider, first and second transistors, and a DC to DC converter. The voltage divider operatively coupled to the first and second transistors is capable of evenly dividing the input voltage across the first and second transistors. The DC to DC converter operatively coupled to the transistors, the voltage divider, and the opto-isolator is capable of maintaining an output current from the rectifier. The use of the DC to DC converter, the voltage divider, and the transistors provide benefit of reducing a power dissipated throughout the entire circuit.

Opto-isolator multi-voltage detection circuit

Antenna assemblies for wireless communications in explosive environments are described. An example antenna assembly has a housing, a base member at one end of the housing, and an antenna extending through the base member and into the housing. A sealing compound within the base member encapsulates the antenna to seal the antenna at the base member.

Antenna apparatus for explosive environments

A device intended to meet flameproof approval requirements is configured to have two compartments separated by an energy-limiting barrier. The first compartment of the device houses the wiring terminations that bear ignition-capable energy and, therefore, must be flameproof. The energy-limiting barrier is configured to limit the energy that can reach the second compartment to a level that is not ignition capable. This allows the second compartment to be safe without meeting the flameproof requirements, and allows user-interface elements such as switches and indicators to be designed in a more cost-effective manner.

Flameproof apparatus using non-grounded energy-limiting barrier

The present invention is directed to a method of reprogramming a field device in a process control network using the standard communications protocol for the network, and a reprogrammable field device in the process control network adapted for being reprogrammed using the standard communications protocol for the network. The method and device of the present invention use the standard communications protocol to transmit the downloaded code to the field device and store the downloaded code in the field device while the device is enabled to perform process control. Once the new code is downloaded and stored in the field device, the field device is set to a steady state condition and/or disabled from performing process control, reprogrammed to execute the downloaded code, and reenabled to perform process control.

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Marshalltown, IA, United States of America

Clyde Thomas Eisenbeis