Abstract:
The present invention is directed to a electrical wiring device that includes a housing having a plurality of line terminals and a plurality of load terminals, the plurality of load terminals including a plurality of receptacle terminals. A cover assembly is coupled to the housing. The cover assembly includes at least one set of receptacle openings disposed on either side of a central portion of the cover assembly. Each of the at least one set of receptacle openings is in communication with a portion of the plurality of receptacle terminals. A fault detection assembly is coupled to the plurality of line terminals. The fault detection circuit is configured to provide a fault detection output in response to detecting a fault condition. A circuit interrupter is coupled between the plurality of line terminals and the plurality of load terminals. The circuit interrupter includes a first set of contacts configured to provide at least one electrically continuous path between the plurality of line terminals and the plurality of load terminals in a reset state. The first set of contacts is configured to disconnect the at least one electrically continuous path in response to the fault detection output to thereby enter a tripped state. A light assembly is coupled to the plurality of line terminals or the plurality of load terminals. The light assembly has a light transmission region disposed in the central portion and occupying a substantial portion of a width of the cover assembly. The light assembly is selectively driven from a deenergized state to a light emitting state in response to a predetermined stimulus.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation-in-part of U.S. patent application Ser. No. 11/609,793 filed on Dec. 12, 2006 and U.S. patent application Ser. No. 10/998,369 filed on Nov. 29, 2004, the content of which is relied upon and incorporated herein by reference in its entirety, and the benefit of priority under 35 U.S.C. §120 is hereby claimed, U.S. patent application Ser. No. 10/998,369 claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 60/550,275, this application is also a continuation-in-part of U.S. patent application Ser. No. 11/294,167 filed on Dec. 5, 2005, which is a continuation-in-part of U.S. patent application Ser. No. 11/242,406 (Now U.S. Pat. No. 7,285,721) filed on Oct. 3, 2005, which is a continuation application of U.S. patent application Ser. No. 10/726,128 filed on Dec. 2, 2003 (now U.S. Pat. No. 6,989,489), the contents of which are relied upon and incorporated herein by reference in its entirety, and the benefit of priority under 35 U.S.C. § 120 is hereby claimed, U.S. patent application Ser. No. 10/726,128 claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application 60/439,370 filed Jan. 9, 2003. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to electrical wiring devices, and particularly to electrical wiring devices having safety features. 
         [0004]    2. Technical Background 
         [0005]    The AC power interface for the typical electrical distribution system is commonly known as the breaker panel. The size of the breaker panel may vary depending on whether it is disposed within a residence, commercial building or some other such facility. The breaker panel, of course, terminates the AC power service provided by the power utility and distributes AC power to one or more branch electric circuits installed in the structure. Branch electric circuits often include one or more electrical wiring devices, such as receptacle outlets, that accommodate electrical power plugs. 
         [0006]    Electrical wiring devices are provided in electrically non-conductive housings. The housing includes electrical line terminals that are electrically insulated from electrical load terminals. The line terminals connect the wiring device to conductive wires from the breaker panel. Load terminals are connected to downstream wiring that is configured to propagate AC power to one or more downstream electrical loads. Those of ordinary skill in the pertinent art will understand that the term “load” refers to an appliance, a switch, or some other electrically powered device. The load terminals of an electrical wiring device are sometimes referred to as “feed-through” terminals. As alluded to above, the AC power propagating through a device may be accessed by the user by way of a power plug. As everyone knows, the power plug and cord assembly for a portable electrical device functions as a portable device&#39;s AC power interface. A receptacle outlet provide power to portable “user-accessible loads” when the plug is inserted into a receptacle outlet. Certain types of faults are known to occur in branch electric circuits and electrical wiring systems. These faults represent serious safety issues that may result in fire, shock or electrocution if not addressed properly. 
         [0007]    Accordingly, branch electric circuits typically employ one or more electric circuit protection devices. Protective devices employ a circuit interrupter disposed between the line terminals and the load terminals. The circuit interrupter provides power to the load terminals under normal conditions, but breaks electrical connectivity when the protective device detects a fault condition in the load circuit. There are several types of electric circuit protection devices including ground fault circuit interrupters (GFCIs), ground-fault equipment protectors (GFEPs), arc fault circuit interrupters (AFCIs), transient voltage surge suppressors (TVSSs), or surge protective devices (SPDs). This list includes representative examples and is not meant to be exhaustive. Some devices include both GFCIs and AFCIs. As their names suggest, arc fault circuit interrupters (AFCIs), ground-fault equipment protectors (GFEPs) ground fault circuit interrupters (GFCIs), transient voltage surge suppressors (TVSSs), or surge protective devices (SPD&#39;s) perform different functions. Electric circuit protective devices may be disposed within a circuit breaker that provides overcurrent protection, receptacle outlets, plugs, etc. Portable electrical wiring devices, e.g., hair dryers, etc., may also have a protective device disposed therein. 
         [0008]    Another safety issue that is of great concern relates to the amount of ambient lighting in a given room or space. In a scenario that most people are familiar with, a person entering a darkened room will usually attempt to locate the wall switch and turn the wall switch to the ON position before entering. Sometimes the wall switch is not located near the door, i.e., at the point of entry, and the person will begin to search for the light switch. This person begins to “feel” her way around the darkened room in an attempt to navigate around objects such as tables and chairs. More often than not, the person successfully finds the wall switch and manages to turn the lights ON. On the other hand, the darkened room represents a safety issue. For example, if an object is disposed relatively low to the floor surface the person may trip over it and suffer an injury. This scenario applies to other types of spaces, such as corridors, theater aisles, stairways, patios, garages, ingress/egress areas, out-buildings, outdoor pathways and the like. 
         [0009]    There are situations where a light switch is not available, or is not readily available. There are other situations where the person entering the darkened room is disinclined to turn the lights ON as a matter of courtesy. Several examples immediately come to mind. A person entering a darkened theatre would expect to incur the wrath of his fellow patrons if he turned the theatre lights ON while finding a seat. In another situation, a person may desire to temporarily enter a room occupied by a person who is sleeping. For example, a parent may want to check on the condition of a sleeping infant, or tend to someone who is ill, without having to turn the lights ON. 
         [0010]    In one approach that has been considered, a portable lighting device may be inserted into an electrical receptacle located in the room to function as a “night light.” While this arrangement may provide a temporarily solution to the potentially unsafe condition described above, it has certain drawbacks associated with it. The most obvious drawback in getting the portable nightlight into a socket in a darkened room is finding the socket in the first place. While this problem may be eliminated with forethought, many people live busy lives and have other things on their minds. On the other hand, once the night light is inserted into the receptacle, it may remain there day and night for an extended period of time and represent a waste of energy. After awhile, the resident may notice the problem and unplug the light during daylight hours if the space admits natural light. Unfortunately, the resident may forget to plug the light back into the socket until after night fall and finds himself revisiting the darkened room scenario. In addition, once a small night light is unplugged from the receptacle there is the possibility that it will become lost, misplaced, or damaged from excessive handling. 
         [0011]    In another approach that has been considered, a light element may be disposed in a wiring device in combination with another functional element such as a receptacle or a light switch. The wiring device is subsequently installed in a wall box or mounted to a panel. While this approach obviates some of the drawbacks described above, there are other drawbacks that come into play. Conventional permanent lighting elements such as incandescent and neon lights have a relatively short life expectancy of only a few years and, therefore, require periodic servicing and/or replacement. This problem is exacerbated by the fact that the light is typically hard-wired to power contacts disposed in the wiring device. As such, the light element is permanently ON, further limiting the light elements life expectancy of the device. 
         [0012]    In yet another approach that has been considered, the aforementioned drawbacks are addressed by providing a light sensor, and the associated circuitry, to control the light element. When the sensor detects the ambient light level falling past a certain point, the control circuit turns the light element ON. One design problem associated with using a light sensor to selectively actuate the light element relates to providing a proper degree of isolation between the light sensor and the light element. Conventional devices solve the problem by separating the light sensor and the light element by as great a distance as possible. As such, conventional devices are typically arranged such that the lens covering the light element is disposed in one portion of the wiring device cover and the sensor element is disposed in a second portion of the cover, with sufficient space therebetween. If the wiring device includes another functional element such as a receptacle, the sensor may be disposed between the receptacle and the light&#39;s lens cover. Because the light sensor must be disposed a sufficient distance away from the light element, it necessarily requires that the lighting assembly be reduced in size to fit the wiring device form factor. Accordingly, conventional devices of this type often fail to provide an adequate amount of illumination for the intended application and, therefore, do not address the safety concern in a satisfactory manner. 
         [0013]    What is needed is an electrical wiring device that includes a light source that is both adapted to a wiring device form factor and configured to address the drawbacks and needs described above. A light emitting wiring device is needed that provides a sufficient amount of illumination when the ambient light in a given space falls below a safe level. The wiring device must maximize the effective area of illumination without sacrificing sensor isolation. What is also needed is a wiring device that addresses both safety issues, i.e., electrical fault conditions as well as ambient lighting issues. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention addresses the needs described above by providing an electrical wiring device that includes a light source that is both adapted to a wiring device form factor and configured to address the drawbacks and needs described above. The wiring device of the present invention may be configured to address both safety issues, i.e., electrical fault conditions as well as ambient lighting issues. 
         [0015]    One aspect of the present invention is directed to a electrical wiring device that includes a housing having a plurality of line terminals and a plurality of load terminals, the plurality of load terminals including a plurality of receptacle terminals. A cover assembly is coupled to the housing. The cover assembly includes at least one set of receptacle openings disposed on either side of a central portion of the cover assembly. Each of the at least one set of receptacle openings is in communication with a portion of the plurality of receptacle terminals. A fault detection assembly is coupled to the plurality of line terminals. The fault detection circuit is configured to provide a fault detection output in response to detecting a fault condition. A circuit interrupter is coupled between the plurality of line terminals and the plurality of load terminals. The circuit interrupter includes a first set of contacts configured to provide at least one electrically continuous path between the plurality of line terminals and the plurality of load terminals in a reset state. The first set of contacts is configured to disconnect the at least one electrically continuous path in response to the fault detection output to thereby enter a tripped state. A light assembly is coupled to the plurality of line terminals or the plurality of load terminals. The light assembly has a light transmission region disposed in the central portion and occupying a substantial portion of a width of the cover assembly. The light assembly is selectively driven from a deenergized state to a light emitting state in response to a predetermined stimulus. 
         [0016]    Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
         [0017]    It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a schematic of the electrical wiring device in accordance with a first embodiment of the present invention; 
           [0019]      FIG. 2  is an exploded view of the device shown in  FIG. 1 ; 
           [0020]      FIG. 3  is a perspective view of the device shown in  FIG. 1  without the cover assembly or back body; 
           [0021]      FIG. 4  is a perspective view of the shutter assembly optionally employed in conjunction with the present invention; 
           [0022]      FIG. 5  is a perspective view of the device shown in  FIG. 1  without the center night light lens; 
           [0023]      FIG. 6  is a perspective view of the fully assembled device shown in  FIG. 1 ; 
           [0024]      FIG. 7  is a schematic of the electrical wiring device in accordance with a second embodiment of the present invention; 
           [0025]      FIG. 8  is a schematic of the center night light assembly in accordance with the second embodiment of the present invention; 
           [0026]      FIG. 9  is an exploded view of the device shown in  FIG. 7 ; 
           [0027]      FIG. 10  is a schematic of the electrical wiring device in accordance with a third embodiment of the present invention; 
           [0028]      FIG. 11  is an exploded view of the device shown in  FIG. 11 ; 
           [0029]      FIG. 12  is a perspective view of the center night light assembly in accordance with the third embodiment of the present invention; 
           [0030]      FIG. 13  is a schematic of the center night light assembly in accordance with the third embodiment of the present invention; 
           [0031]      FIG. 14  is a schematic of an alternate center night light circuit in accordance with the present invention; 
           [0032]      FIG. 15  is a schematic of yet another alternate center night light assembly in accordance with the present invention; and 
           [0033]      FIG. 16  is a perspective view of the fully assembled device in accordance with the third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of the electrical wiring device of the present invention is shown in  FIG. 2 , and is designated generally throughout by reference numeral  10 . 
         [0035]    As embodied herein, and depicted in  FIG. 1 , a schematic  100  of an electrical wiring device  10  in accordance with an embodiment of the present invention is disclosed. In this example, the schematic shows a protective device that includes ground fault interrupter circuitry. Device  10  includes line terminals ( 2 ,  4 ), load terminals ( 6 ,  8 ), and receptacle terminals ( 300 ,  320 ). Again, the load terminals  6 ,  8  may also be referred to herein as feed-through terminals. As noted above, these terminals may be connected to wiring configured to provide power to downstream receptacles or switches. Receptacle load terminals  300 ,  320  are configured to mate with an electrical plug to provide power to an appliance or other such user attachable loads. The line terminals  2 ,  4  are electrically connected to both load terminals  6 ,  8  and receptacle terminals  300 ,  320  when device  10  is reset. When in the tripped state, the circuit interrupter  120  disconnects the load terminals from the line terminals. In addition, the circuit interrupter may disconnect at least one feed-through terminal from a corresponding receptacle terminal. 
         [0036]    The ground fault circuitry includes a differential transformer  102  which is configured to sense load-side ground faults. Transformer  104  is configured as a grounded neutral transmitter and is employed to sense grounded-neutral fault conditions. Both differential transformer  102  and grounded-neutral transformer  104  are coupled to detector circuit  106 . Power supply  112  provides power for GFI detector circuit  106 . Note that in this embodiment, the lighting assembly  200  is disposed in series with power supply  112 . The light assembly  200  will be described in greater detail below. Referring back to the operation of the detection circuit, detector  106  provides an output signal on output pin  7  based on the transformer outputs. The detector output signal is filtered by circuit  108 . Filter circuit  108  filters out noise to thereby substantially reduce the possibility of false tripping. The filtered output signal is provided to the control input of SCR  110 . When SCR  110  is turned ON, solenoid  116  is energized. Solenoid  116  actuates the trip mechanism to thereby trip circuit interrupter  120 . The trip solenoid  116  is energized until the circuit interrupter trips to remove the fault condition. Accordingly, there is no signal at output pin  7  and SCR  110  is turned OFF. The time that the solenoid remains energized is less than about 25 milliseconds. After the fault condition has been eliminated, circuit interrupter  120  may be reset by way of reset button  260 . 
         [0037]    Although  FIG. 1  has disclosed a ground fault circuit interrupter circuit, those of ordinary skill in the art will understand that the present invention should not be construed as being limited to GFCIs. The present invention is suitable for use in other types of protective devices such as AFCIs. For example, the sensor in an AFCI is similar to transformer  102  but is typically configured to sense load current by way of a toroidal transformer or a shunt and/or line voltage by way of a voltage divider. The detector in an AFCI is similar to detector  106  but is configured to detect an arc fault condition on the basis of frequency spectra or high frequency noise bursts. Once an arc fault condition is detected, a signal is sent in a similar manner to an SCR which in turn activates a trip mechanism to trip the circuit interrupter. The TVSS (SPD) is another example of a protective device. During a lightning storm, the TVSS (SPD) limits the voltages in the distribution system to a safe level. The TVSS includes a voltage surge suppressing structure between hot and neutral terminals such as spark gap  130 . Surge suppressing devices may be disposed between hot and ground terminals or between neutral and ground terminals. The surge suppressing device(s) are selected from a family of devices that includes spark gaps, MOVs, varistors, capacitors, avalanche and devices. More than one surge suppressing component may be disposed between a pair of terminals. Thus the spirit of the invention disclosed herein applies to GFCIs and to protective devices in general. 
         [0038]    The present invention addresses certain end of life conditions by denying power when the device is unable to function. One end of life condition may cause the solenoid to remain energized when a fault condition is not present or when the circuit interrupter is in a tripped state. The solenoid is susceptible to burn-out when SCR  110  is permanently ON. This typically happens when SCR  110  is permanently shorted out. Most solenoids are configured to be energized only momentarily. They tend to burn out if energized for more than about 1 second. Once the solenoid burns out, the circuit interrupter is incapable of being tripped. As a result, the load terminals are permanently connected to the line terminals even when there is a fault condition. 
         [0039]    In this embodiment, solenoid burn-out is prevented by an auxiliary switch  114 . Auxiliary switch  114  is configured to open when circuit interrupter  120  is in the tripped position. If SCR  110  is shorted, or is permanently ON, auxiliary switch  114  ensures that solenoid  116  is not permanently connected to a current source. Accordingly, if reset button  260  is activated, circuit interrupter  120  resets but immediately trips in response to the trip mechanism, which in turn moves auxiliary switch  114  to the open position before solenoid  116  is able to burn out. 
         [0040]    The auxiliary switch  114  provides other benefits. Those of ordinary skill in the art will understand that a metal oxide varistor (MOV) is frequently employed in protective devices to protect the electrical circuit from voltage surges that sometimes occur in the electrical distribution system. The end-of-life failure mode of a MOV is typically an electrical short. The resulting current can be enough to thermally damage the enclosure of the protective device. In one embodiment of the present invention, MOV  118  is connected in series with auxiliary switch  114  and trip solenoid  116  to eliminate most over-current situations. Thus, when MOV  118  reaches end of life and shorts out, trip solenoid  116  is energized to open auxiliary switch  114  and the flow of short circuit current is terminated before any damage ensues. 
         [0041]    As noted above, the light assembly  200  is disposed in series with power supply  112 . The schematic shows that the light assembly  200  includes at least two light emitting diodes  202 . As such, light emitting diodes  202  are energized when the circuit interrupter  120  is reset and deenergized when the device is tripped. Thus, the light assembly  200  functions as a reset indicator in this embodiment. 
         [0042]    Referring to  FIG. 2 , an exploded view of the device  10  embodying the schematic provided in  FIG. 1  is shown. The device housing includes a back body  12  and separator member  14 . The electromechanical components forming GFCI  100  are disposed therebetween. The GFCI  100  is inserted into back body  12  such that the line terminals ( 2 ,  4 ) and the load terminals ( 6 ,  8 ) are accessible to the installer. The spark gap structure  130  is disposed between the line terminals ( 2 ,  4 ). The separator is a molded member configured to accommodate both the various GFCI structures disposed underneath it as well as the receptacle terminal structures ( 30 ,  32 ) disposed above. 
         [0043]    The neutral receptacle terminal structure  30  includes neutral face receptacle terminals  300  and a fixed contact  302 . The terminal structure  30  is disposed in alignment slots formed in the separator  14  such that fixed contact  302  extends through separator  14  in alignment with the cantilevered line and load contacts in GFCI  100 . The cantilevered structure is shown in greater detail in  FIG. 3 . The hot receptacle structure  32  is the mirror image of the neutral receptacle structure, and therefore, includes hot face receptacle terminals  320  and hot fixed contact  322 . The ground strap  16  is also mounted within separator  14 . The ground strap  16  includes an offset feature  162 . The amount of offset roughly corresponds to the thickness of the tamper-resistant shutter mechanism  18 . The offset  162  accommodates the thickness of the shutter mechanism  18  such that the front surface of the cover assembly  20  is flush with the wall plate after the device  10  is installed. 
         [0044]    In this embodiment, LEDs  202  are connected to the printed circuit board  101  via pigtail wires (not shown for clarity of illustration) that extend through the separator  14 . The LEDs  202  are inserted into a reflector portion  204  formed within the front cover assembly. Reflector  204  is described in greater detail below. 
         [0045]    The cover assembly  20  includes face receptacle openings  22  disposed at either end thereof. A test button opening  24 , reset button opening  26 , and night light opening  208  are disposed in the surface area between the receptacle openings  22 . Obviously, the test button opening  24  accommodates the test button  240  and the reset opening  26  accommodates the reset button  260 . The night light opening  208  extends across substantially the entire width of mesa  21 , which is the raised portion of the cover member  20 . The night light is configured to accommodate lens element  206 . Of course, the reflector member  204  is coupled to the underside of the cover  20  within opening  208 . 
         [0046]    The reset button  260  includes a stem portion  262  and coil spring  264  that extend through strap  16  and into the latch block disposed in GFCI  100 . Therefore, the reset button is disposed on the central longitudinal axis of the device alongside the night light opening  208 . The test button  240  is disposed alongside the reset button  260  on one side of the central latitudinal axis opposite the night light opening  208 , which is disposed on the other side of the axis The major axis of the user accessible surfaces of the test and reset buttons are substantially normal to each other. 
         [0047]    Turning now to the structure of the lighting assembly  200 , in one embodiment, the reflector is a molded portion of the front cover. Of course, those of ordinary skill in the art will understand that the reflector  204  may be formed separately and snapped into place within opening  208  of front cover  20 . The interior surface of the reflector  204  may be imbued with its reflective quality using any suitable method. For example, the surface may be formed using a relatively shiny white plastic material that is naturally reflective. The surface may be polished like a mirror. A reflective surface may be disposed over a plastic surface by painting or plating techniques known to those of ordinary skill in the art. Of course, separator  14  includes apertures disposed therein (not shown) that accommodate the LEDs  202 . Those of ordinary skill in the art will understand that there may be one or more LEDs  202  employed within the scope of the present invention. In one embodiment, the LEDs are implemented using white LEDs that have a minimum 100° viewing angle. The amount of light emitted by each LED on its optical axis is greater than about 500 MCD (millicandelas). The reflector and lens are configured so that the intensity of the light emitted by LEDs  202  into a region of space surrounding device  10  is greater than about 20 millifootcandles. In another embodiment, the intensity of the emitted light is greater than about 50 millifootcandles. 
         [0048]    Lens  206  is substantially flush with the front surface of the cover member  20 . As noted previously, lens  206  extends across the full width of the front cover member  20 . In one embodiment, the surface area of lens  206  measures 0.300 inches by 1.160 inches. Lens  206  is approximately 0.14 inches thick. If the separator is molded into the front cover  20 , lens  206  snaps into opening  208  from the top. In an alternate embodiment (see  FIG. 9 ), lens  206  has a “U-shaped” cross-section, having the same cross-sectional profile as “mesa”  21  formed in front cover  20 . Lens  206  wraps around mesa  21  when it is inserted from above. Lens  206  may have lenticular lens elements formed on the interior surface disposed adjacent to the LEDs  202 . As those of ordinary skill in the art will understand, lenticular lens elements diffuse incident light to thereby provide uniform illumination. 
         [0049]    In yet another embodiment of the present invention, the combination of the LEDs  202 , plug tail wires, separator  204 , and lens  206  may be installed as a single unit that is snapped into the front cover. 
         [0050]    Referring to  FIG. 3 , a perspective view of the GFCI  100  portion of device  10  is shown with the back body  12 , separator  14 , and cover member  20  not shown. Of particular note is the position of the receptacle terminal structures ( 30 ,  32 ) with respect to the line and load cantilevers. Neutral line terminal  4  includes a line terminal which extends into the interior of the GFCI device. The neutral line cantilever includes contact  122  disposed at the end thereof. Neutral load terminal  8  also includes a cantilever having dual contact  126  at the end thereof. Contacts  122  and  126  are vertically aligned with fixed contact  302 . Only hot fixed contact  322  may be seen on the “hot side of the circuit interrupting structure. However, those of ordinary skill in the art will understand that the hot interrupting contacts ( 124 ,  128   322 ) and the neutral interrupting contacts ( 122 ,  126 ,  302 ) form the four-pole circuit interrupter  120  that is shown schematically in  FIG. 1 . The LEDs  202  (lighting assembly  200 ) appear to be suspended in space in  FIG. 3 . In actuality, the LEDs  202  are connected to printed circuit board  101  via pig tail wires that are not shown in this view for clarity of illustration. 
         [0051]    As embodied herein and depicted in  FIG. 4 , a perspective view of the shutter assembly optionally employed in the first embodiment of the present invention is shown. Reference is made to U.S. patent application Ser. Nos. 10/729,685, 10/900,778, and 11/609,793, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of various embodiments of the protective shutter assembly  18 . The shutter assembly may be optionally employed in any of the embodiments disclosed herein. 
         [0052]    When assembled, the upper shutter  190  is inserted into lower shutter  170  until stop members  1920  extend beyond rail guides  1782  and snap into place. This position represents the closed position, wherein the upper transverse structure  196  covers neutral aperture  174  (not shown) and upper base  198  covers hot aperture  176  (not shown). The lower shutter member  170  and the upper shutter member  190  are movable relative to each other from the closed position to the open position in response to being simultaneously engaged by the hot plug blade and the neutral plug blade of an electrical plug. To facilitate this movement, shutter members ( 170 , 190 ) are made from a family of plastics having natural lubricity. These include nylon 6-6, Delrin, and Teflon. Shutter members ( 170 , 190 ) may be made from a substrate on which these materials are coated, the substrate having a differing flammability or flexural characteristic. 
         [0053]    If a foreign object having a width substantially the same as a hot plug blade is inserted into the hot receptacle opening, the shutter assembly remains closed. The foreign object causes ramp  1784 , and therefore, lower shutter  170 , to move. However, this foreign object insertion does not cause upper shutter  190  to move relative to shutter  170 . As a result, the foreign object inserted into the hot receptacle opening strikes base member  198  of the upper shutter. On the other hand, if a foreign object having a width substantially the same as a neutral plug blade is inserted into the neutral receptacle opening, transverse structure  196  will move upper shutter  190  but not move lower shutter  170 . Accordingly, the lower base member  173  does not move and the neutral aperture  174  (not shown) is not exposed. Thus, the foreign object inserted into the neutral receptacle opening strikes lower base member  173 . 
         [0054]    Only when the hot plug blade and the neutral plug blade of an electrical plug simultaneously engage ramp  1784  and ramp  1962 , respectively, will the lower shutter member  170  and the upper shutter member  190  move relative to each other from the closed position to the open position. In the open position, the lower hot aperture  176  is aligned with the upper hot contact aperture  194  and, the inward edge of the lower neutral contact aperture  174  is substantially aligned with the outer edge of ramp  1962 . In this position, the lower shutter  170  and the upper shutter  190  allow the plug contact blades to pass through the protective shutter  18  and engage the contacts disposed in the interior of the electrical wiring device. On the other hand, a foreign object such as a hairpin is likely to slide off of either side of ramp  1784  or ramp  1962 . Obviously, if the foreign object has slid off the ramp, force cannot be applied to the object to open the corresponding shutter. 
         [0055]    In another embodiment, the predetermined electrical plug geometry that opens the shutters may include only some of the characteristics that have been described. The geometry may include just one or more of the following: two plug blades separated by a predetermined distance, plug blades contacting the two blade structures simultaneously, a neutral plug blade having a predetermined width, or a hot plug blade having a predetermined width. Plug blade width will not matter if ramps  284  and/or  462  approach the widths of their respective contact structures. 
         [0056]    In another embodiment, shutters ( 170 ,  190 ) open in response to the insertion of two objects without particular heed given to their geometries. This may be accomplished by extending the widths of ramp  1784  and ramp  1962  so that regardless of the sizes of the objects, there is nowhere for either or both objects escaping the ramps as they are inserted into the device. As such, it is assured that the two shutters will open. 
         [0057]    The movement of the upper shutter  190  and the lower shutter  170  is effected by spring member  180 . The spring member  180  is configured to bias the frameless shutter sub-assembly, i.e., lower shutter  170  and upper shutter  190 , in the closed position. Spring member  180  is compressed further in the open position and, therefore, opposes movement of the frameless shutter sub-assembly from the closed position to the open position. Accordingly when the electrical plug is removed, the spring moves the frameless shutter sub-assembly from the open position to the closed position. Stated differently, only a single spring is necessary to effect the closed position of the shutter assembly. 
         [0058]    As alluded to above, the protective shutter assembly  18  includes a spring retainer mechanism. The spring retainer mechanism includes lower shutter retainer pocket  1780  and upper shutter retainer pocket  1960 . The spring retainer mechanism is configured to retain the spring member  180  within the frameless shutter sub-assembly and substantially prevent the spring member from being separated from the frameless shutter sub-assembly. As those of ordinary skill in the art will appreciate, the protective shutter assembly  18  may be dropped and/or exposed to vibrational and/or mechanical forces during automated assembly. As shown in  FIG. 4 , retainer pockets ( 1780 ,  1960 ) are equipped with retainer lips that prevent the spring member from being jarred loose. 
         [0059]    Referring to  FIG. 5 , a perspective view of device  10  without the center night light lens  206  is shown. This view clearly shows reflector member  204  disposed within the front cover member  20 . In the embodiment shown, two LEDs  202  are disposed within the reflector member  204 . The “bathtub” shape of the interior surface of the reflector is configured to redirect light emitted from the side portions of LEDs  202  out from opening  208 . As noted above, the reset button  260  and test button  240  are disposed adjacent to the light assembly  200  in the manner previously described.  FIG. 6  is a perspective view of the fully assembled device with lens element  206  in place. The lens element is substantially flush with respect to the front surface of cover member  20 . 
         [0060]    As embodied herein, and depicted in  FIG. 7 , a schematic of a circuit protection device  10  in accordance with a second embodiment of the present invention is disclosed. The schematic shown in  FIG. 7  is almost identical to the one shown in  FIG. 1 . In  FIG. 1 , the lighting assembly  200  is disposed between resistors R 7  and R 8 . In  FIG. 7 , light assembly  200  is not included in the power supply circuit  112 . The power supply includes diode D 1 , and resistors R 6 , R 7 , and R 8  in series. In this second embodiment, the hot receptacle terminal structure  32  is connected to the light assembly  200  by way of connection “A”. The neutral receptacle terminal structure  30  is connected to the light assembly  200  by way of connection “B”. Because the other elements in the schematic shown in  FIG. 7  are identical to  FIG. 1 , the description of the circuit is not repeated for brevity&#39;s sake. 
         [0061]    Referring to  FIG. 8 , a schematic of the center night light assembly  200  in accordance with the second embodiment of the present invention is shown. As shown in  FIG. 7 , connection “B” is connected to the neutral receptacle terminal structure  30 . The light assembly circuit  200  includes a current rectifying diode D 1  in series with LEDs  202  and current limiting resistors R 80 , and R 82 . Comparing  FIG. 7  and  FIG. 8 , it becomes apparent to those skilled in the art that the lighting assembly  200  again functions as a reset indicator. When the device is in the reset state, LEDs  202  are ON. When the device is tripped, the LEDs  202  are OFF. 
         [0062]      FIG. 9  is an exploded view of the second embodiment of the present invention previously discussed relative to  FIGS. 7-8 .  FIG. 9  is very similar to the exploded view previously shown in  FIG. 2 . Accordingly, a description of like features is omitted for brevity&#39;s sake and only the differences are explained. In the second embodiment, lens  206  has a “U-shaped” cross section similar to the cross-sectional profile as “mesa”  21  formed in front cover  20 . Lens  206  wraps around mesa  21  when it is inserted into opening  208  from above. Another difference between the first embodiment and the second embodiment relates to the light assembly  200  implementation. In the second embodiment, the light assembly  200  is disposed on a satellite printed circuit board  201 . Connection points “A” and “B” are implemented as soldered pig tail wires disposed between PCB  201  and the terminal structures  30 ,  32 . 
         [0063]    As embodied herein and depicted in  FIG. 10 , a schematic of a circuit protection device  10  in accordance with a third embodiment of the present invention is disclosed. The schematic shown in  FIG. 10  is very similar to the schematics provided in  FIGS. 1 and 7 . Again, in  FIG. 10 , light assembly  200  is not included in the power supply circuit  112 . Like the second embodiment, the hot receptacle terminal structure  32  is connected to the light assembly  200  by way of connection “A”. The neutral receptacle terminal structure  30  is connected to the light assembly  200  by way of connection “B”. Any description of the circuit elements ( FIG. 10 ) that are identical to those shown in  FIG. 1  and  FIG. 7  would be repetitious and superfluous, and therefore, is omitted. 
         [0064]    The third embodiment includes an additional indicator  150  disposed in parallel with auxiliary switch  114 . As noted above, the auxiliary switch  114  is configured to open when circuit interrupter  120  is in the tripped position. If SCR  110  is shorted, or is permanently ON, auxiliary switch  114  ensures that solenoid  116  is not permanently connected to a current source. Accordingly, if reset button  260  is activated, circuit interrupter  120  resets but immediately trips in response to the trip mechanism, which in turn moves auxiliary switch  114  to the open position before solenoid  116  is able to burn out. The indicator  150  is implemented as a trip indicator, emitting a visual and/or audible indicator signal when circuit interrupter  120  is in the tripped state, i.e., when the auxiliary switch  114  is open. The trip indicator LED  150 , therefore, is energized when there is power on the line terminals and the circuit interrupter is in the tripped condition. The indicator  150  is OFF when device  10  is in the reset state. Indicator  150  may be implemented as a red LED or as an audible indicator, or both. The indicator may also be configured to emit a repetitive signal (flashing or beeping). 
         [0065]      FIG. 11  is an exploded view of the device shown in  FIG. 10 . In this embodiment, cover  20  includes indicator opening  28  for indicator  150 . Indicator  150 , which is disposed on the main PCB  101 , is in optical communication with opening  28  by way of light pipe  152 . Notched opening  27  accommodates lens window element  270 . Lens  270  is configured to cover the ambient light sensor  212 . The window lens  270  may be implemented using a translucent “wrap-around” lens of the type shown in  FIG. 11 , or alternatively, the front cover  20  may include an integral translucent lens portion. In any event, lens  270  is configured to direct the ambient light in the spatial volume proximate device  10  toward ambient light sensor  212 . 
         [0066]    The window or lens are disposed in the front user accessible surface of the device, or alternatively, may “wrap around” the edge of the user accessible surface. Reference is made to U.S. patent application No. (905P300), which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of the sensor lens element  270 . Ambient light is transmitted to the ambient light sensor  212  by way of the two outer surfaces of the wrap-around lens. These two surfaces are approximately normal to each another. An optical blocking structure is included such that light sensor  212  receives ambient light but not light emitted by light assembly  212 . In one approach, reflector member  204  is made out of an opaque material. In another, the inner (or outer surfaces) of the reflector member are painted or plated with an opaque material. In another, the ambient light sensor  212  is mounted such that the printed circuit board  201  serves as a blocking structure. In another, the light blocking structure is connected to (or integral to) the front cover  20  or separator member  14 . In another, lens  270  includes a light pipe disposed to couple ambient light, instead of light generated by the wiring device, to the light sensor. In yet another, the wrap-around lens is configured for sensing ambient light predominantly from the side surface of front cover  20 . This configuration reduces the likelihood that reflected light from lens  206  will pollute the ambient light. 
         [0067]    Referring to  FIG. 12 , a detail perspective view of the center night light assembly  200  in accordance with the third embodiment of the present invention is shown. As shown, white LEDs  202  are connected to PCB  201 . PCB  201  is disposed between terminal structure  30  and terminal structure  32  in the manner shown. The pig tail connections (A, B) are not shown in this view. 
         [0068]    The main PCB  101  may be manufactured in a “six up array.” PCB  101  has a non-rectangular shape, necessitating the removal of excess printed circuit board material. This material is typically wasted. However, the size of the waste regions are big enough to be used as satellite boards  201 . Thus, the use of the satellite boards represents an efficient use of material. 
         [0069]    Note that the test button  240  is coupled to PCB  201  via compression spring  244 . Moveable switch member  242  is connected to test button  240 . Switch member  242  is formed from an electrically conductive material that need not be flexible. Spring  244  biases test switch member  242  in the open position. In the open position, there is an air gap between contact  2420  and one end of the switch member, and another between hot receptacle contact structure  32  and the other end of switch member  242 . When the test button is depressed, the test switch is closed. Switch member  242  bridges hot receptacle terminal  32  and contact  2420 . Contact  2420 , of course, is coupled to the neutral line conductor in the manner shown in  FIG. 7 . This structure facilitates the novel arrangement of the test button, reset button  260 , and the light assembly within the center portion of the cover assembly  20 . Because of the added functionality in the third embodiment, there is not enough room in the device for a cantilever beam actuated by the test button. Instead of a cantilever, a compression switch structure  242  is included. This switch mechanism has two advantages. First, it is more compact than a cantilever structure. Second, by virtue of the switch closing two air gaps instead of one air gap, the test button need only travel half the distance to make connection. The reduced distance is important because the compact switch structure does not provide the mechanical advantage that is provided by the traditional cantilever test blade. As shown in the schematic ( FIG. 10 ), the test switch is connected in series with resistor R 1 , typically 15K Ohms. Reference is made to U.S. patent application No. 905P185, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a dual air gap test button switch. 
         [0070]    Referring to  FIG. 13 , a schematic of the center night light assembly in accordance with the third embodiment of the present invention is shown. Again, the satellite PCB  201  receives power from the receptacle terminals  30 ,  32 , which are connected at points “A” and “B”, respectively. When the ambient light is above a certain level, light sensor  212  reacts to the ambient light level and diode D 3  begins to conduct. In one embodiment, sensor  212  is implemented using a light sensing diode and the amount of current conducted by sensor  212  is related to the amount of incident ambient light. As the ambient light increases past a predetermined level, which may be adjusted by potentiometer R 6  in the factory, the Darlington transistor pair (Q 1 , Q 2 ) are turned OFF. In particular, the current flow through D 4  pulls down the base of transistor Q 1 . Q 1 , in turn, pulls down the base of Q 2 . When the ambient light begins to decrease, e.g., as night falls, the current flowing through sensor  212  begins to decrease accordingly. At some predetermined ambient light level, the current flowing through sensor  212  diminishes to the point where a current flow through diode D 3  and resistor R 1  is established. Subsequently, the transistors Q 1  and Q 2  are turned ON collector/emitter current in Q 2  flows energizing LEDs  202 . 
         [0071]    In the schematic shown in  FIG. 13 , a dimmer potentiometer  216  is provided, allowing the user to adjust the brightness of the LEDs  202 . In another embodiment, light sensor  212  may be implemented using a light sensing variable resistor. In this embodiment, sensor  212  and resistor  214  function as a voltage divider. Therefore, the voltage presented to diode D 3  changes in accordance with the variable resistance of sensor  212 . Additional features and benefits may be included. For example, the circuit may be configured to provide hysteresis. For example, the amount of ambient light at which LEDs  202  turn ON may differ from the amount of ambient light at which LEDs  202  turn OFF in accordance with the selected hysteresis curve. LEDs  202  can only be energized when two conditions are met. Device  10  must be reset and the ambient light level must fall below a predetermined level. Thus, the light assembly  200  in this embodiment is not a reset indicator per se. 
         [0072]    In another embodiment of the present invention, the sensor circuitry may be replaced, or augmented by, proximity, motion sensing, or temperature sensing circuitry. While the sensor circuitry may function as strictly an ON/OFF control of the nightlight assembly  200 , it may also be configured to regulate the power to the nightlight such that the luminous intensity is proportional to the incident ambient light. Reference is made to U.S. patent application No. (905P184 CIP1), which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of this type of light sensor circuitry. 
         [0073]    Referring to  FIG. 14 , a schematic of an alternate center night light circuit in accordance with the third embodiment of the present invention is shown. The circuit depicted herein is similar to the one shown in  FIG. 13  except that dimmer potentiometer  216  is coupled to a switch S 1  that is normally in the open position. Switch S 1  is coupled in parallel with transistors Q 1  and Q 2 . When the user goes beyond one of the adjustment limit of potentiometer  216 , switch S 1  is configured to close to provide a “full-on” bypass. In this mode, the LEDs are fully lit regardless of the intensity of the ambient light. 
         [0074]    The dimmer potentiometer  216  is also coupled to a switch S 2  that is normally in the closed position. Switch S 2  is connected in series with transistors Q 1  and Q 2 . When the user adjusts potentiometer  216  beyond the other adjustment limit of potentiometer  216 , switch S 2  is configured to open to provide a “full-off” bypass. In this mode, the LEDs are never lit regardless of the intensity of the ambient light. Those of ordinary skill in the art will understand that switch S 1  and switch S 2  may be used alone or in combination with each other. 
         [0075]      FIG. 15  is a schematic of yet another alternate center night light assembly in accordance with the third embodiment of the present invention. In this embodiment, light assembly  200  is an “intelligent pilot light,” meaning that more light is emitted in response to a greater amount of room ambient light. Photosensitive device  212  conducts an amount of current governed by the intensity of ambient light. When the intensity of the ambient light increases beyond some preset value, the current propagating through D 3  will turn on Q 1  and Q 2 . As a result, diodes D 1  and D 2  emit light. As the room ambient light increases, Q 1  and Q 2  are ON for a longer duty cycle and D 1  and D 2  emit an increasing intensity of light. Dimmer potentiometer  216  allows a user to adjust the intensity of the light emitted by D 1  and D 2 . Switch S 1  or S 2  may be included. They provide a similar functionality to S 1  and S 2  described in  FIG. 20 . 
         [0076]    In another embodiment of the present invention, a secondary power source, such as a battery or a charged capacitor, may be disposed within the housing  12  as a back-up power source when the primary AC power source provided by the electrical distribution system has failed. Reference is made to U.S. patent No. (905P 184 CIP1), which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a secondary power source. 
         [0077]    Referring to  FIG. 16 , a perspective view of the fully assembled device  10  in accordance with the third embodiment of the present invention is disclosed. This view illustrates the novel arrangement of the light assembly lens  206 , indicator lens  152 , test button  240 , reset button  260 , and sensor lens  270  within the space between the receptacle openings  22  in cover  20 . 
         [0078]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0079]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. 
         [0080]    The recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. 
         [0081]    All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0082]    It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.