Abstract:
A tester is disclosed for testing a wiring state of a live electrical receptacle outlet. The tester comprises a body having a display located thereon and a plug extending from the body. The display is configured to selectively provide a text indicator. When the plug of the tester is received in the electrical outlet, the display indicates the wiring state of the electrical outlet.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/067,171 entitled “LCD RECEPTACLE TESTER” filed on Feb. 26, 2008, the contents of which are hereby incorporated by reference their entirety. 
    
    
     STATEMENT CONCERNING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     FIELD OF THE INVENTION 
     The present invention relates to a tester for verifying the correct wiring of an electrical receptacle outlet. 
     BACKGROUND OF THE INVENTION 
     Receptacle outlet testers are conventionally used to verify the correct wiring of a wall electrical outlet. Among other things, a receptacle tester can be used to determine whether an outlet is functioning (i.e., would provide power to an attached device) and whether the wiring is safe (i.e., whether improper wiring would result in damage to an attached device or create a situation in which a person may receive an electrical shock). 
     Conventional receptacle testers, such as the prior art receptacle tester  10  shown in  FIG. 1 , have a body  14  and a plug  12  that extends from the body  14 . The plug  12  includes three prongs (one for hot contact, one for neutral contact, and one for ground contact) for connection in the corresponding receptacles of an electrical outlet. The receptacle tester  10  also has three indicators  16  and a code label  18  located on the body  14 . The code label  18  lists the wiring states for each of the indicator combinations. A ground fault circuit interrupter tester, such as a button  20 , is also available on the receptacle tester  10 . 
     When the plug  12  of the receptacle tester  10  is plugged into a live outlet, one or more of the indicators  16  may light up indicating the wiring status of the outlet. The user compares the on/off pattern of the three indicators  16  to the code label  18  to determine whether the outlet is correctly wired. If the outlet is not correctly wired, then the code label  18  indicates what is incorrect about the wiring so that the user may make the necessary changes before the outlet is put into service. 
     However, under certain conditions, it can be difficult for the user to read the code label or see the indicator lights. Since receptacle testers are generally quite compact, the text printed on the code label is frequently small—making the code label difficult to read. Additionally, as at least the outlet being tested is not in service, the receptacle tester is often being used in a poorly lit area. Moreover, as not all outlets are similarly oriented, upon insertion of the receptacle tester in the outlet, it may be difficult for the user to consult the code label or see the indicators, particularly if the outlet is upside-down. 
     Hence, there is a need for an improved receptacle tester that provides easy analysis of the output provided by the receptacle tester and that can be used on outlets having various orientations. 
     SUMMARY OF THE INVENTION 
     A tester is disclosed for testing a wiring state of a live electrical receptacle outlet. The tester includes a body having a display located thereon and a plug extending from the body. The display is configured to selectively provide a text indicator. When the plug of the tester is received in the electrical outlet, then the display indicates the wiring state of the electrical outlet. 
     In one form of the tester, the display may be a liquid crystal display. 
     In another form of the tester, the display may be located on a surface of the body of the tester opposite to a surface of the body from which the plug extends. In this form, when the plug is inserted into an outlet for testing, the display is on a plane generally parallel with a plane on which the electrical outlet is located. 
     In yet another form, the tester may further include a sensor configured to detect the spatial orientation of the tester relative to a direction of gravity. In this form, the display is configured to orient a text message displayed on the text indicator based on the spatial orientation of the tester. 
     In still yet another form, the tester may further include a level mounted to a surface of the body of the tester. In some forms, the level may be a bubble level. 
     In other forms, the plug extending from the body may have a plurality of prongs. The plurality of prongs may include two flat prongs and a round prong. In this form, one of the flat prongs may be polarized relative to the other flat prong and the round prong may be a ground. 
     In one form, the tester further may include a ground fault circuit interrupter tester. 
     In another form, the display of the tester may be powered by a battery. 
     In still yet another form, the body of the tester may further include a rotational joint between the display and the plug. In some forms, the rotational joint may be located between the display and at least a portion of the body. In one form, an axis of rotation between the display and the body may be substantially parallel with a direction of insertion of the plug. In another form, the axis of rotation between the display and the body may be substantially perpendicular with a direction of insertion of the plug. 
     In another form, the tester may include a first half of the body including the plug and a second half of the body including the display. The rotational joint may be located between the first half and the second half of the body. 
     In still another form, when the plug of the tester is received in the electrical outlet, the display may indicate the wiring state of the electrical outlet by providing a text message on the text indicator. 
     Thus, a tester is disclosed that provides easy analysis of the wiring status of an outlet by a text display. Instead of comparing indicator lights to a code label or the like, the user may simply consult the display which provides a text message indicating the wiring status. The user does not need to take the additional mental step of comparing an indicator light sequence to a code label. Further, in many forms of the disclosed tester, the display is either rotatable or senses the spatial orientation of the tester to orient the text message in a more readable way to the user. 
     These and still other advantages of the invention will be apparent from the detailed description and drawings. What follows is merely a description of some preferred embodiments of the present invention. To assess the full scope of the invention the claims should be looked to as these preferred embodiments are not intended to be the only embodiments within the scope of the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top side view of a prior art receptacle tester; 
         FIG. 2  is a top side view of a receptacle tester having a text display; 
         FIG. 3A  is an alternative form of the receptacle tester in which the display is located on the front side of the receptacle tester and the receptacle tester is being plugged into an outlet having a typical orientation; 
         FIG. 3B  is a front side view of the receptacle tester of  FIG. 3A  after being plugged into the outlet; 
         FIG. 4A  is a view of the receptacle tester of  FIGS. 3A and 3B  being plugged into an outlet having a reverse orientation; 
         FIG. 4B  is a front side view of the receptacle tester of  FIG. 4A  after being plugged into the outlet; 
         FIG. 5  is a front side view of another form of the receptacle tester in which the receptacle tester further includes a bubble level; 
         FIG. 6A  is a front view of the receptacle tester having a bubble level, as in  FIG. 5 , inserted into an outlet that is not vertically aligned; 
         FIG. 6B  is a front view of the receptacle tester having a bubble level, as in  FIG. 5 , inserted into an outlet that is vertically aligned; 
         FIG. 7A  is a top view of another form of the receptacle tester in which there is a rotatable joint between the display and the body of the receptacle tester; 
         FIG. 7B  is a top view of yet another form of the receptacle tester in which there is a rotatable joint between the two sections of the body of the receptacle tester; 
         FIG. 7C  is a top view of still yet another form of the receptacle tester having a rotatable text display in which the axis of rotation is in a direction perpendicular to the direction of plug insertion; and 
         FIG. 8  is a schematic of the receptacle tester. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 2 , a receptacle tester  100  has a body  102  with a liquid crystal display  104  located on a surface  106  of the body  102 . The liquid crystal display  104  is designed such that it is capable of providing a text indicator. A plug  108  extends from the body  102  and includes two flat prongs  110  and  112  and a ground prong  114 . A button  116  is also located on the surface  106 . The button  116  serves as a ground fault circuit interrupter (GFCI) tester. 
     The receptacle tester  100 , when plugged into an outlet, displays the wiring state of the outlet on the liquid crystal display  104 . As shown in  FIG. 2 , an “OPEN NEUTRAL” wiring state is displayed. It is contemplated that other wiring states may be displayed on the liquid crystal display  104  including, but not limited to, “OPEN GROUND”, “OPEN HOT”, “HOT/GRD REV”, “HOT/NEU REV”, and “CORRECT”. Because the wiring state is displayed directly onto the liquid crystal display  104 , the user does not need to reference a code label to interpret the indicators common to standard receptacle testers. Moreover, the font size of the text on the liquid crystal display  104  can be much larger than the font size commonly found on code labels, as only a single wiring state needs to be displayed at a time. Thus, the liquid crystal display  104  displays the wiring state in an easily readable manner. The liquid crystal display  104  could also be configured to display the wiring state in one or more languages simultaneously or to be toggled between one or more languages using a control or the like. 
     As most liquid crystal displays are powered by direct current (DC) and most outlets provide alternating current (AC), it may be necessary to use a liquid crystal display  104  that can be powered using alternating current, convert the alternating current into a direct current usable by the display, or power the liquid crystal display  104  using a separate battery. If a separate battery is added, it is contemplated that “DEAD” or a similar phrase may be displayed on the liquid crystal display  104  as the battery runs out of energy to indicate that the battery needs to be changed. 
     Although the receptacle tester  100  is described as having a liquid crystal display  104 , any display suitable for display of a text message could be used. The display could be monochromatic or multi-colored and may optionally be electroluminescent or have backlighting to improve readability of the display, particularly in dark or dimly lit areas. 
     Further, the plug  108  may be any one of a number of different types of plugs. Although the plug  108  is shown as being a Type-B plug (American 3-pin or U-ground), other plugs may be used based on regional or national standards. 
     Referring now to  FIGS. 3A and 3B , the plug  108  of the receptacle tester  100  is shown as being inserted into an outlet  118  having a typical orientation (two prongs on top and a single ground prong on the bottom). The side of the receptacle tester  100  having the GFCI button  116  will be referred to as the top side  120  of the receptacle tester  100 . Notably, in the form shown in  FIGS. 3A and 3B , the liquid crystal display  104  is located on the front side of the receptacle tester  100  such that it is located on the opposite side of the receptacle tester  100  relative to the plug  108 . Thus, when the plug  108  is plugged into an outlet  118  on a vertical surface, the liquid crystal display  104  is on a plane generally parallel to the plane on which the outlet  118  is located. As shown in  FIG. 3B , the liquid crystal display  104  displays the wired status of the outlet  118  such that it is readable to an upright viewer. 
     Referring now to  FIGS. 4A and 4B , the plug  108  of the receptacle tester  100  of  FIGS. 3A and 3B  is inserted into an outlet  118  having a reversed or upside-down orientation (a single ground prong on top and two flat prongs on the bottom). As can be seen in  FIG. 4B , the top side  120  of the receptacle tester  100  faces downward when plugged into the outlet having this upside down or reversed orientation. As will be described in more detail below, a sensor  134  inside the receptacle tester  100  detects the spatial orientation of the sensor  134  relative to the direction of gravity (which is opposite the UP direction indicated in  FIGS. 3B and 4B ). 
     With additional reference to the schematic of  FIG. 8  depicting the functional portions of the receptacle tester  100 , when the receptacle tester  100  inserted into an upside-down outlet as in  FIGS. 4A and 4B , the spatial sensor  134  determines that the receptacle tester  100  is turned upside-down. The processing circuitry  136  inside the receptacle tester  100  receives this information from the spatial sensor  134  and orients the text displayed on the liquid crystal display  104  such that the text is oriented in the UP direction. Thus, in  FIG. 4B , the displayed text has been flipped 180 degrees, such that it can still be easily read by a user viewing the display  104  from an upright position. 
     In this way, the liquid crystal display  104  is easily read regardless of the orientation of the receptacle tester  100 . In contrast, when the prior art receptacle indicator  10  is plugged into the outlet  118  having the upside-down or reversed orientation, a user would have difficulty observing either the code label  18  or the indicators  16 . 
     In some forms, the receptacle tester  100  may have moveable parts such that the orientation of the liquid crystal display  104  relative to the plug  108  may be manually adjusted by twisting, rotating, and/or otherwise moving different parts of the receptacle tester  100  relative to one another. Depending on the specific structure of the receptacle tester  100 , it may be desirable to place mechanical restrictions on the range of rotation such that, for example, wires connecting the parts are not damaged during the rotation of the liquid crystal display  104  relative to the plug  108 . 
     For example, in one form, such as is shown in  FIG. 7A , a rotational joint  132  may connect the liquid crystal display  104  to the rest of the body  102  such that the display  104  can be swiveled relative to the body  102 . 
     In another form, such as is shown in  FIG. 7B , the body  102  may be bifurcated such that the plug  108  may be on one portion  102   a  of the body  102  and the liquid crystal display  104  may be on another portion  102   b  of the body  102 . For easy viewing by the user, the portions  102   a  and  102   b  may be connected at a rotational joint  132  such that the liquid crystal display  104  can be rotated relative to the plug  108  along an axis of plug insertion. As shown in  FIG. 7B , the display  104  is located on a surface of the body portion  102   b  that is easily viewable from the top or bottom of the receptacle tester  100 , depending on the rotation. However, the display  104  could also be located on the front face of the receptacle test similar to  FIGS. 3-6 . 
     In still yet another form, such as is shown in  FIG. 7C , the display  104  is swivelable relative to the body  102  of the receptacle tester  100  about a rotary axis perpendicular to the axis of plug insertion. A pair of joints  138  rotatably connect the display  104  to the body  102  of the receptacle tester. At least one of the pair of joints  138  may be hollow such that a wire  140  can connect the display  104  to the processing circuitry  136 . 
     In operation of the embodiment shown in  FIG. 7C , the user inserts plug  108  into an electrical outlet. Then, depending on the orientation of the outlet, the user can rotate the display  104  to a preferred viewing angle. The orientation of the displayed text may be based at least in part upon a spatial sensor  134 . Further, the orientation could be based at least in part upon a detected orientation of the display  104  relative to the body  102 . 
     Yet another embodiment of the receptacle tester  100  is shown in  FIGS. 5 ,  6 A, and  6 B. In this embodiment, a bubble level  122  having a bubble  124  and center marks  126  is placed on one of the faces of the receptacle tester  100 . As in  FIGS. 3A ,  3 B,  4 A, and  4 B, the liquid crystal display  104  is located on the front face of the receptacle tester  100 . 
     When the receptacle tester  100  is plugged into an outlet, the bubble level  122  can be used to determine whether the outlet is properly aligned or not. For example, in  FIG. 6A , which has vertical reference lines  128  and  130 , the bubble  124  in the bubble level  122  is off-center (i.e., outside of the center marks  126 ) as the outlet  118  is not vertically aligned. In contrast, in  FIG. 6B , the outlet  118  is properly vertically aligned with vertical reference lines  128  and  130  and the bubble  124  is within the center marks  126 . 
     The level is not restricted to being only a bubble level and may be operable whether or not a current is being supplied to the outlet  118 . It is further contemplated that the sensor used to detect the orientation of the receptacle tester may serve as a level and the display  104  may indicate whether or not the outlet is level. 
     The inclusion of a level permits an outlet to be oriented in a particular direction with precision. Since outlet fixtures do not commonly have long flat surfaces that can be used to level the outlets using traditional levels, the receptacle tester  100 , when plugged into the outlet  118 , provides a point of engagement for use as a reference point in aligning the outlet. 
     Although the attempted vertical alignment of an outlet  118  is shown in  FIGS. 6A and 6B , one or more levels may be placed on the various surfaces of the receptacle tester  100  to align the outlet along a direction other than the vertical direction. For example, a level may be placed at a 90 degree angle from the bubble level  122  shown in  FIGS. 6A and 6B  to orient an outlet along a horizontal direction. 
     Preferred embodiments of the invention have been described in considerable detail. Many modifications and variations to the preferred embodiments described will be apparent to a person of ordinary skill in the art. Therefore, the invention should not be limited to the embodiments described.