Patent Application
20140062579
This patent relates generally to fluid control devices and, more particularly, to apparatus for fluid control device monitoring.
Sensors may be used to determine an actual valve position. Based on the sensor reading, the sensor outputs a value, which may be used to control the position of the valve.
An example apparatus in accordance with the teachings of this disclosure includes a body through which a shaft extends. The shaft is to be coupled to an actuator. An angular position of the shaft is based on a position of the actuator. The apparatus includes a target coupled to the shaft and a circuit including a user configurable switch and a proximity switch. The user configurable switch is configurable to a first state or a second state. When the user configurable switch is in the first state and the target is distant from the proximity switch, the circuit is to output a first signal. When the user configurable switch is in the second state and the target is distant from the proximity switch, the circuit is to output a second signal different than the first signal.
Another example apparatus in accordance with the teachings of this disclosure includes a resistor and first and second switches. The resistor is in parallel with the first and second switches. The first switch is in series with the second switch. The first switch is responsive to a target and the second switch is responsive to user input. An output of the apparatus is to change based on the user input when the target is proximate the first switch or when the target is at a distance from the first switch.
Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify the same or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, several examples have been described throughout this specification. Any features from any example may be included with, a replacement for, or otherwise combined with other features from other examples.
The examples disclosed herein relate to configurable Namur interface circuitry and/or valve top monitoring systems for fluid control device monitoring. Depending on the configuration of the example circuitry, a current output increases or decreases if a target is present. Thus, a single apparatus may be used in applications having different electrical requirements while outputting standard Namur switch current levels when the target is or is not present. In some examples, the interface circuitry provides Namur output with Exna certification such that an additional intrinsically safe barrier is not needed.
In some examples, the Namur circuitry includes a field-effect transistor (FET), first and second resistors, a user configurable switch and a proximity sensor (e.g., a mechanical proximity switch). To provide a different result (e.g., high or low current output) based on the same proximity sensor reading, the user configurable switch is responsive to user settings. For example, with the user configurable switch in a first state and/or setting and the proximity sensor in the normally closed position, the output current may be at a first and/or higher value (e.g., 3 milliamps and/or greater than 3 milliamps). However, if the user configurable switch is in a second state and/or setting when the proximity switch is in the normally closed position, the output current may be at a second and/or lower value (e.g., 1 milliamp and/or less than 3 milliamps).
The switch 108 may be a user configurable switch (e.g., a dip switch) that is responsive to user input and the switch 110 may be a proximity sensor or a switch responsive to one or more targets 112, 114. The targets 112, 114 may be metal, magnets, ferromagnetic material, etc. In some examples, the switch 108, the switch 110 and/or the housing 102 are hermetically sealable to enable the apparatus 100 to be used in hazardous and/or underwater locations. In some examples, the housing 102 and/or other components of the apparatus 100 may be made and/or molded using high-temperature resistant materials (e.g., plastics) to enable the apparatus 100 to be used in high-temperature environments. In some examples, the housing 102 may include one or more internal and/or external light-emitting diodes (e.g., LEDs) to indicate the state of the switch 108 and/or the switch 110.
In operation, the circuit 106 receives an input voltage of between about 8 and 30 volts direct current and the shaft 105, which is coupled to an actuator, changes its rotational and/or angular position based on the position of the actuator. The positions of the targets 112, 114 relative to the switch 110 change based on the position of the shaft 105. The targets 112, 114 are movably coupled within respective slots (e.g., serrated slots) 116, 118 of a follower and/or segmented plate 120 coupled to the shaft 105. Based on the position of the target 114 relative to the switch 110, the current output of the circuit 106 changes.
In some examples, if the target 114 is detected by the switch 110 and the switch 108 is in a first state, the circuit 106 is not shorted and the current output is relatively low. In some examples, if the target 114 is detected by the switch 110 and the switch 108 is in a second state, the circuit 106 is shorted and the current output is relatively high. Thus, the example apparatus 100 can be used in different applications having electrical configurations that expect the amperage to be higher or lower when the target 114 is present.
In operation, depending on the expected output, the second switch 218 may be in a first state and/or coupled to a normally closed segment (NC2) 220 or in a second state and/or coupled to a normally open segment (NO2) 222. When the first and second switches 216 and 218 are coupled to the normally closed segment 220 (e.g., in a first state), as shown in
When the first switch 216 is coupled to the normally open segment 222 and the second switch 218 is coupled to the normally closed segment 220, the second resistor 214 is not shorted and the output current is decreased. When the first switch 216 and the second switch 216 are coupled to the normally open segment 222, the second resistor 214 is shorted and the output current is increased.
As set forth herein, an example apparatus includes a body through which a shaft extends. The shaft is to be coupled to an actuator. An angular position of the shaft is based on a position of the actuator. The apparatus includes a target coupled to the shaft and a circuit includes a user configurable switch and a proximity switch. The user configurable switch is configurable to a first state or a second state. When the user configurable switch is in the first state and the target is distant from the proximity switch, the circuit is to output a first signal. When the user configurable switch is in the second state and the target is distant from the proximity switch, the circuit is to output a second signal different than the first signal.
In some examples, the user configurable switch is in the first state and the target is proximate the proximity switch, the circuit is to output the second signal. In some examples, when the user configurable switch is in the second state and the target is proximate the proximity switch, the circuit is to output the first signal. In some examples, the user configurable switch includes a single pole, double throw switch or a dip switch. In some examples, the first signal has a magnitude greater than the second signal. In some examples, when the user configurable switch is in the first state and the target is distant from the proximity switch, a resistor of the circuit is shorted. In some examples, when the user configurable switch is in the second state and the target is proximate the proximity switch, a resistor of the circuit is shorted.
Another example apparatus includes a body through which a shaft extends. The shaft is to be coupled to an actuator and a target is coupled to the shaft. The apparatus includes a proximity sensor responsive to the target and means for obtaining different outputs when the target is proximate the proximity sensor or when the target is at a distance from the proximity senor. In some examples, the means for obtaining different outputs includes a user configurable switch configurable to a first state or a second state. In some examples, when the user configurable switch is in the first state and the target is at the distance from the proximity sensor, a circuit is to output a first current value. In some examples, when the user configurable sensor is in the second state and the target is distant from the proximity sensor, the circuit to output a second current value different than the first current value.
In some examples, when the user configurable switch is in the first state and the target is proximate the proximity sensor, the circuit is to output the second current value. In some examples, when the user configurable switch is in the second state and the target is proximate the proximity sensor, the circuit is to output the first current value. In some examples, when the user configurable switch is in the first state and the target is at the distance from the proximity sensor, a resistor of the circuit is shorted.
Another example apparatus includes a resistor and first and second switches. The resistor is in parallel with the first and second switches. The first switch is in series with the second switch. The first switch is responsive to a target and the second switch is responsive to user input. An output of the apparatus is to change based on the user input when the target is proximate the first switch or when the target is at a distance from the first switch.
In some examples, the apparatus also includes a second resistor in series with the first resistor and the first and second switches. In some examples, the first switch includes a proximity sensor. In some examples, the second switch includes a single pole, double throw switch. In some examples, an input voltage of the apparatus is to be between about 8 volts and 30 volts. In some examples, when the second switch is in a first state and the target is at the distance from the first switch, the output is to be a first current value. In some examples, when the second switch is in a second state and the target is at the distance from the first switch, the output is to be a second current value different than the first current value. In some examples, the first current value has a magnitude greater than the second current value.
Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
