Abstract:
A control system for hazardous environments decreases flame paths, decreases punctures to the control system when installing interfaces, and increases safety. The control system may be characterized as a “one size fits all” controller that is able to automatically recognize a plurality of user interfaces. The controller has an enclosure to which the interfaces can be attached. The interfaces may interact with control electronics wholly contained in the enclosure using a variety of “wireless” mechanisms. Such mechanisms include reflecting light waves, infrared (IR) communication, radio-frequency identification, inductive coils, short-range wireless communication, camera images, piezoelectricity, and magnetism, and the like. The interfaces may include switches, indicator lights, smoke detectors, and the like.

Description:
BACKGROUND 
       [0001]    This application relates generally to a control system, and more specifically to a control system for various environments including hazardous environments. 
         [0002]    Present control systems are comprised of hundreds of components. Such a large number of components complicates the manufacturing process and leads to increases in costs and time of manufacturing. Such complexity also affects distributor&#39;s stock of components. Additionally, devices used in current controllers have a significant number of flame paths. These flame paths decrease safety and can affect reliability of the devices and controller. 
       BRIEF SUMMARY 
       [0003]    According to one example described herein, a control system comprises: an enclosure comprising an opening on a front face and electronics for controlling a device; and at least one interface mounted to the front face of the enclosure, which at least partially covers the opening and which is physically isolated from the electronics, wherein the at least one interface is configured to communicate with the electronics. 
         [0004]    In various embodiments of the above example, the enclosure has at least one of an inlet and an outlet through which electronics or wiring of the device controlled by the control system pass; the enclosure has a light source and a light detector, and the interface is optically connected to the electronics via the light source and the light detector; the at least one interface comprises optical element for altering a path of light emitted by the light source and a moveable aperture, the moveable aperture being movable to shield or expose the optical element in response to a mechanical actuation of the interface; when the optical element is exposed to light emitted by the light source, the light is reflected toward the light detector; and when the optical element is shielded from light emitted by the light source, the light is not reflected toward the light detector, wherein detection of reflected light by the light detector is indicative of a state of the interface; the electronics control at least one operation of a device based on the state of the interface that corresponds to the device; the interface comprises pivotable or rotatable mirror, the mirror being pivotable or rotatable in response to an actuation of the interface; in a first position of the pivotable or rotatable mirror, light emitted by the light source is reflected toward the light detector; and in a second position of the pivotable or rotatable mirror, light emitted by the light source is not reflected toward the light detector, wherein detection of reflected light by the light detector is indicative of the state of the interface; the electronics control a device based on the state of the interface; the interface has a light mixing chamber and a clear cover for viewing light from the light source, the light source being operated in response to a status of a device controlled by the controller; the enclosure has a first inductive coil and/or a first short-range wireless device, the first short-range wireless device being a receiver, transmitter, and/or transceiver, the interface has a second inductive coil and/or a second short-range wireless device, the second short-range wireless device being a receiver, transmitter, and/or transceiver, and the interface is wirelessly connected to the electronics via the first inductive coil and/or the first short-range wireless device; the first inductive coil and second inductive coil are short-range wireless devices for transferring power and data; the interface has a light source, light detector, and a moveable shield, the moveable shield being moveable into and out of a space between light source and the light detector in response to a mechanical actuation of the interface by a user to interrupt or allow transmission of light from the light source to the light detector; communication between the first inductive coil and/or first short-range wireless device, and the second inductive coil and/or second short-range wireless device is based on whether light from the light source is detected by the light detector; the electronics control a device based on the communication; the interface has a mechanical or electrical switch that is actuated between a first state and a second state in response to a mechanical actuation of the interface by a user; communication between the first inductive coil and/or first short-range wireless device, and the second inductive coil and/or second short-range wireless device is based on the state of the switch; the electronics control a device based on the communication; the interface has a light source, a light mixing chamber, and a clear cover for viewing light from the light source, the light source being operated in response to communication between the first inductive coil and/or first short-range wireless device, and the second inductive coil and/or second short-range wireless device; the enclosure has a camera configured to generate images of a pattern on the interface, the pattern being rotated or otherwise altered in response to a mechanical actuation of the interface by a user; the electronics control a device based on an analysis of pattern in the images; each of the at least one interfaces has a unique identifier communicated to the electronics, such that the electronics can automatically recognize the interface; the interface is a smoke detector, such that the interface detects smoke when light emitted by the light source is not detected by the light detector; the enclosure is an explosion-proof enclosure for use in hazardous environments and physically isolates the at least one interface from the electronics which reduces a number of flame paths associated with the system; the interface comprises a piezo-electric element that generates a current upon actuation of the interface, and wherein the current is utilized for communication between the interface and the electronics; the interface comprises at least one magnetic element and at least one sensor, and wherein the sensor detects a magnetic flux caused by actuation of the magnetic element; the interface comprises a capacitive touch element that generates a current upon actuation of the interface, and wherein the current is utilized for communication between the interface and the electronics; the device may be controlled by a physical user input at the at least one interface or automatically by comparison of a signal value to a threshold. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIGS. 1A-1D  is an illustration of perspective views of controllers having zero, one, two, and three devices; 
           [0006]      FIG. 2  is a cross-section of a controller illustrating three example devices; 
           [0007]      FIG. 3  is a cross-section of a controller illustrating another three example devices; and 
           [0008]      FIG. 4  is a cross-section of a controller illustrating another three example devices. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Certain terminology is used herein for convenience only and is not to be taken as a limitation on the claimed invention. Relative language used herein is best understood with reference to the drawings, in which like numerals are used to identify like or similar items. Further, in the drawings, certain features may be shown in somewhat schematic form. 
         [0010]    Generally, the controller can be described as comprising two aspects. According to a first aspect, the controller can be fitted with a plurality of devices, which may be auto-recognized by the controller. According to a second aspect, the interfaces (e.g., switches, actuators, relays, lights, and the like) associated with each of the plurality of devices are used to control and operate the respective devices. 
         [0011]    Turning now to  FIG. 1 , a controller  100  has a box-shaped enclosure  102  comprising an inlet  104 , an outlet  106 , and a front face  108 . The enclosure  102  may be, for example, a NEMA7 explosion-proof metallic enclosure. The inlet and outlet provide connections for devices operated and controlled by the controller. A circuit board  210  comprising a processor(s)  212  and associated electrical components may be mounted within the enclosure  102 . The components and processor  212  of the circuit board  210  control the devices of the controller  100 . As illustrated in the figures, the inlet  104  and outlet  106  are provided on opposite sides of the controller enclosure  102 . However, the shape and configuration illustrated in the figures is not intended to be limiting and it is noted that the controller  100  and enclosure  102  can take on any shape, size, or configuration. For example, in other embodiments (not illustrated), the enclosure may be a “back box” having a single outlet or inlet, or be a standalone box with no outlets or inlets. 
         [0012]    With respect to the first aspect described herein, the front face  108  of the enclosure  102  may be fitted with a plurality of interfaces  110  associated with devices of the controller  100 . The front face  108  provides an opening  112  to the interior of the enclosure  102  on which the plurality of interfaces  110  may be mounted across. The opening  112  may be recessed into the enclosure  102  and a circuit board  210  may be positioned within the recessed opening. 
         [0013]    Each interface  110  may be mounted or installed by securing the interface  110  to the exterior of the front face  102  of the enclosure  102  using bolts, screws, adhesives, and the like. In this way, the interfaces  110  fully extend over and cover the opening  112  along one direction. Additional interfaces  110  may cover or overlap the opening  112  along the other direction. Any portion of the opening  112  not covered by interfaces  110  may be covered by patches or “blank” pieces and these blanks maybe similar in size and/or shape to any of the interfaces present thereon or may have a different appearance from the interfaces  110 . The interfaces  110  may also be collectively installed as single unified piece that may completely cover the opening  112 . 
         [0014]    Each interface  110  may comprise substantially the same general size and/or shape relative to the opening  112  of the enclosure  102 . In other words, each interface  110  may be installed or applied to the enclosure  102  using a common form factor. This eliminates a need for unique drilling of the controller  100  and enclosure  102  to suit individual interface  110  and device requirements. This further eliminates additional penetrations through the controller  100  and enclosure  102 , thereby decreasing flame paths and improving safety. 
         [0015]    Specific examples of interfaces according to the second aspect are described herein with respect to  FIGS. 2-4 . According to a first example illustrated in  FIG. 2 , an interface  200  may comprise a stationary mirror  202  and a movable aperture  204 . While a mirror is described herein, it is noted that various embodiments could use any optical element that can alter a path of light, such as a lens or prism. A mechanical button (e.g., a spring biased push button) may be depressed to operate the movable aperture, so as to expose or shield the mirror. A light source (e.g., light emitting diode (LED) with narrow optics, such as a collimator)  206  and light detector  208  electrically connected to the circuit board  210  and processor  212  may be located underneath the mirror  202 . The light source  206  and light detector  208  may be tunable to particular wavelengths/bandwidths of light. In this way, a light wave emitted by the light source  206  is directed toward the mirror  202 . The interface  200  may be operated (e.g., by a push button  214 ) to expose and shield the mirror  202  by moving the movable aperture  204 . When the interface  200  is operated such that the mirror  202  is exposed, the light wave is reflected back toward the circuit board  210 , where it is detected by the light detector  208 . Similarly, when the mirror  202  is shielded, light is neither reflected back toward nor detected by the light detector  208 . In some embodiments, operation or actuation of the interface  200  may operate to alter light emitted by the light source  206  such that only a particular wavelength/bandwidth of light reaches the light detector  208 . Thus, each scenario as described (e.g., light detected, no light detected, particular wavelength/bandwidths of light detected) may be associated with a state of the interface  200 . The depression of the button  214  of the interface  200  changes the state of the interface  200 , thereby controlling or determining a current state of the interface  200 . Depending on whether light is detected by the light detector  208 , the processor(s)  212  may appropriately operate an associated device according to a desired function controlled by the interface  200 . In other words, for example, a first state of the interface  200  may be intended to cause a device to turn-on and a second state of the interface  200  is intended to cause a device to turn-off. In this instance, when the light detector  208  indicates a first state of the interface  200 , the processor  212  may cause the device to turn on. Similarly, when the light detector  208  indicates a second state of the interface  200 , the processor  212  may cause the device to turn off. 
         [0016]    In another example, also illustrated in  FIG. 2 , an interface  220  comprises a pivoting mirror  222 , a shaft  226  and a button  228 . The shaft  226  extends from and is engaged with the button  228 . The pivoting mirror  222  pivots or rotates about the shaft  226  of the interface  220  when the button  228  is depressed and maintained in this depressed position. The interface  220  may also comprise a diaphragm  224  that environmentally seals the mirror  222  from the button  228 . The mirror  222  may be biased to a position substantially orthogonal to the shaft  226  where light waves from a light source  206  may be reflected back toward a light detector  208  (as described above). Thus, as the button  228  is depressed and the shaft  226  extends away from the diaphragm  224 , the mirror  222  pivots toward a reflecting position (not shown) whereby light is reflected toward the light detector  208 . When the button  228  is depressed again (e.g., to release the button), the shaft  228  and mirror  222  rise toward the diaphragm  224 . The diaphragm  224  may then provide a force to pivot the mirror  222  to a substantially parallel position with the shaft  228 . In this substantially parallel position, no light waves are reflected back toward the light detector  208 . In this way, the button  228  of the interface  220  and detection of reflected light by the light detector  208  may operate a device in a manner substantially similar to that described above with respect to interface  200 . 
         [0017]    It should be noted that the above two examples are not intended to be limiting. Rather, any mechanical mechanism for shielding and exposing a stationary mirror, and/or pivoting or rotating a mirror so as to cause an emitted light wave to be reflected toward a light detector to indicate a state of an interface, is intended to be within the scope of the present disclosure. 
         [0018]    Another interface  240 , as illustrated in  FIG. 2 , is a light that may serve as an indicator or visual signal regarding the state of a controlled device(s) or other interface. The interface  240  may comprise a light pipe or light mixing chamber  242 . A light wave or light waves emitted from one or a plurality of light sources  206  (e.g., LEDs of varying colors) may be directed into the light pipe  242 . If light waves of various wavelengths enter the light pipe  240 , they may be mixed to form a new color. The light in the light pipe  242  may then be visible through an opening or diffused or clear cover  244  of the interface  240 . In this way, the light source(s)  206  may be electrically connected to the processor  212  of the circuit board  210  and may be operated according to logic indicating a current state of a device or other interface. 
         [0019]      FIG. 3  illustrates a plurality of example interfaces ( 300 ,  320 ,  340 ) that use inductive power and wireless communication. The wireless communication can be, for example, short-range communication such as Bluetooth®. According to a first example, an interface  300  comprises a button  302  connected to a shield  304 , a light source  306  (e.g., an LED), a light detector  308 , an inductive coil  310 , and a Bluetooth® transceiver  312 . The light source  306  and light detector  308  are arranged across from each other in the interface  300 . Similar to the examples described above with respect to  FIG. 2 , as the button  302  is depressed, the shield  304  passes between the light source  306  and light detector  308  so as to disrupt communication of a light wave from the light source  306  to the light detector  308 . When the button  302  is pressed again, the shield  304  may rise above the light source  306  and light detector  308  so as to allow the communication of light between the light source  306  and the light detector  308 . In this way, the detection of light, or lack of detection of light (e.g., in the absence of light detection), by the light detector  308  can indicate a state of the button  302  and consequently, a state of the interface  300 . The light detector  308  can be electrically connected to the inductive coil  310  and/or Bluetooth® transceiver  312 , such that the inductive coil  310  and/or Bluetooth® transceiver  312  can be operated according to a state of the interface  300 . 
         [0020]    As with the first example of  FIG. 3 , a second example interface  320  of  FIG. 3  comprises a button  322  connected to a post  324 , a mechanical switch  326 , an inductive coil  328 , and a Bluetooth® transceiver  330 . Rather than using an optical switch to control operation of the inductive coil  328  and/or Bluetooth® transceiver  330  as described above, the second example uses a mechanical switch  326 . More specifically, as the button  322  is depressed, a beveled edge of the post  324  slides across the mechanical switch  326 , thereby depressing the switch  326 . However, in other embodiments, it is envisioned that the post  324  may be conductive so as to close a path between contacts as the button  324  is depressed. In still other embodiments, the post  324  may act as a first contact and, upon depression of the button  324 , make contact with a second contact to close the switch. In any case, the state of the switch  326  is indicative of the state of the button  322 , and the state of the button  322  is indicative of the state of the interface  320 . Thus, the switch  326  is electrically connected to the inductive coil  328  and/or Bluetooth® transceiver  330  so as to control the operation of the inductive coil  328  and/or Bluetooth® transceiver  330  based on the state of the interface  320 . 
         [0021]    A corresponding inductive coil(s)  332  and/or Bluetooth® transceiver(s)  334  are mounted to the circuit board  210  and are electrically connected to the processor(s)  212 . The inductive coil  332  and/or Bluetooth® transceiver  334  of the circuit board  210  can then communicate with the inductive coil(s)  310 ,  328  and/or Bluetooth® transceiver(s)  312 ,  330  of the interfaces  300 ,  320  based on the state of the interfaces  300 ,  320 . In this way, the interfaces  300 ,  320  may operate and control the devices of the controller, as well as receive information from or about the devices of the controller, without being physically connected to the devices, circuit board  210 , or interior of the enclosure  102 . As with the examples described in  FIGS. 2 and 3 , the interfaces  200 ,  220 ,  240 ,  300 ,  320  are situated separate and apart from the interior of the enclosure  102 , and the circuit board  210  is isolated within the interior of the enclosure  102 , thereby increasing safety. 
         [0022]    A third example of an interface  340  illustrated in  FIG. 3  is an indicator light. The indicator light comprises an inductive coil  342 , a Bluetooth® transceiver  344 , a control  346 , a light source (e.g., LED)  348 , and a light pipe or light mixing chamber  350 . The control  346  is electrically connected to the inductive coil  342 , Bluetooth® transceiver  344 , and light source  348 . The indicator light interface  340  operates in a similar, but reversed, manner to the previous two examples of  FIG. 3 . That is, the inductive coil  342  and/or Bluetooth® transceiver  344  receive signals from an inductive coil  332  and/or Bluetooth® transceiver  334  on the circuit board  210 . Based on the signals received therefrom, the control  346  operates the light source  348  so as to emit a light corresponding to or determined by the received signal. The light may be viewed through an opening or transparent/clear cover  352  of the interface  340 . For example, a signal indicating a device status (e.g., power on or error) may be sent to the inductive coil  342  and/or Bluetooth ® transceiver  344  of the interface  340 . The control  346  may interpret this error signal and cause the light source  348  to output a colored light corresponding to the determined state or status of a device. In other embodiments, actuation of an interface may cause a change detectable by the control  346 . For example, actuation of an interface could move an inductor thereby changing the efficiency of the system indicating a change to a device status or state. Such a change could be interpreted by software of the control  346 , or otherwise detected by a hardware sensor element that provides an input to the control  346 . For example, the detection could be the result of comparison to a threshold value. Thus, the actuation results in a change in the operation of the light source  348  by the control  346  according to a state or status of a device. In response to the input, the control  346  may also actuate a device (e.g., a relay or contact). In this way, the control  346  can operate to cause a status or state change and/or then indicate the result of the change. 
         [0023]    Still another example of an interface  400  is illustrated in  FIG. 4 . In the example of  FIG. 4 , a pattern  402  is disposed on an underside of a button  404  (or post of a button) of the interface  400 . A camera  406  mounted to the circuit board  210  and electrically connected to the processor(s)  212  is directed to capture images of the pattern  402 . As the button  404  is depressed, the pattern  402  (and/or post on which the pattern is disposed) may be rotated or otherwise altered. By processing the captured images to determine the pattern  402  or orientation of the pattern  402 , the processor  212  can determine the state of the interface  400 . As with the other interfaces already described, the recognition of the state of the interface can be used to control a corresponding device. 
         [0024]    While the above interfaces have been described as examples, it is noted that these are not intended to be a limiting or inclusive list of such interfaces. For example, a light source and light detector as discussed with respect to  FIGS. 2 and 3  may be used as a smoke detector. That is, a light source may emit a light wave directly toward a light detector or toward a mirror such that the reflection directs the light wave toward a light detector, where failure of the light wave to reach the light detector would indicate the presence of interference such as smoke. Thus, if the light detector fails to detect a light wave or if the detected light has an intensity level below a predetermined threshold value, an alarm or other warning may be sounded indicating the presence of smoke in the enclosure of the housing. In still other variations of the above examples, infrared (IR) emission and/or radio frequency identification (RFID) may be used instead of, or in addition to, the optical mechanisms, inductor coils, and Bluetooth® transceivers. 
         [0025]    Still other interfaces may use piezo-electric and/or magnetic actuation. For example, in a piezoelectric interface, a push button could be used to compress a piezoelectric element, thereby generating an electric current. This current could be used to activate a light source, inductive coil, Bluetooth® transceiver, or the like. Regarding magnetic actuation, a magnetic interface could take advantage of opposing magnets to actuate electrical contacts, without being in physical contact with the electrical contacts. Such a mechanism is described, for example, in U.S. application Ser. No. 14/026,583, which is herein incorporated by reference. Still other embodiments could utilize sensors to detect actuation of a magnetic interface by detecting a magnetic flux caused by the actuation. 
         [0026]    The above described interfaces, and other interfaces envisioned within the scope of the present disclosure, may be automatically recognized by the controller. For example, each interface may have a unique identifying signal output that may be recognized by the processor in the controller. Such signals may be generated according to a reflected light wave pattern, IR pattern, inductive coil transmission, Bluetooth® transmission, RFID, or the like. In this way, the controllers could be further easily assembled by using a standard processor and interior electronics that do not require reconfiguration or reprogramming based on the desired interface(s) used for each controller. 
         [0027]    It is also noted that the interfaces may be potted with a thermos-setting plastic, silicone, or the like so as to resist vibrations, prevent shocks, and further help isolate the interface from the interior of the enclosure. 
         [0028]    A “processor” as used herein refers to any, or part of any, electrical circuit comprised of any number of electrical components, including, for example, resistors, transistors, capacitors, inductors, and the like. The circuit may be of any form, including, for example, an integrated circuit, a set of integrated circuits, a microcontroller, a microprocessor, a collection of discrete electronic components on a printed circuit board (PCB) or the like. The processor may also stand alone or be part of a computer used for operations other than processing image data. It should be noted that the above description is non-limiting, and the examples are but only a few of many possible processors envisioned.