Abstract:
A low voltage power receptacle assembly is provided for use in a modular electrical system. The receptacle assembly includes a housing that defines an internal cavity for receiving and protecting various high and low voltage electrical components, and for providing convenient access to low voltage power outlets associated therewith. The receptacle assembly houses at least two electrical bus bars that are spaced apart and that conduct line voltage received from a relatively high voltage power input. A low voltage transformer has at least two electrical contacts for engaging the electrical bus bars, and is operable to convert the line voltage to a lower output voltage at the power outlets. An isolator body has a non-conductive wall positioned between the electrical bus bars to maintain electrical isolation thereof.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The current application claims the benefit of U.S. provisional application Ser. No. 61/817,711, filed Apr. 30, 2013, which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to low voltage electrical power and/or data outlets or receptacles for use in modular electrical systems. 
     BACKGROUND OF THE INVENTION 
     Low voltage power and data outlets, such as Universal Serial Bus (“USB” and “USB Power”) outlets, are in increasing demand as the number of electrical and electronic devices that use such outlets continues to increase. Such devices may include, for example, mobile phones, computers and computing devices, digital cameras, communications equipment, and the like. Therefore, there has been increasing demand for access to such outlets in work areas, homes, and even public spaces such as airports, shopping malls, and the like. 
     SUMMARY OF THE INVENTION 
     The present invention provides a low voltage power receptacle assembly that is compatible for use in a modular electrical system, such as may be used for providing electrical power in a work area or the like. The low voltage power receptacle assembly includes a power transformer for reducing a line voltage (e.g., 110V AC or 220V AC), that supplies electrical power to standard receptacle outlets, down to a lower voltage (such as about 2V DC to about 12V DC, for example), which is made available to users at a low voltage power receptacle, such as a USB-style receptacle, although other types or configurations of low voltage power receptacles, outlets, or sockets are equally possible. The low voltage power receptacle assembly is compatible for use in multi-circuit modular electrical systems, and may include two or more “hot” electrical conductors, such as bus bars, in order to convey standard line voltage through the low voltage power receptacle assembly, and on to other high or low voltage receptacles or other couplers or power consumers. 
     According to one form of the present invention, a low voltage power receptacle assembly is provided for use in a modular electrical system. The low voltage power receptacle assembly includes a housing, at least two electrical bus bars, a low voltage transformer, and an isolator body. The housing defines a cavity for receiving other components of the assembly, including the bus bars, the transformer, and the isolator body. The electrical bus bars are spaced apart from one another and extend through the housing cavity. The electrical bus bars conduct a line voltage that is received from a power input, and an elongate space is defined between the bus bars. The isolator body includes an elongate non-conductive wall that is positioned in the elongate space between the electrical bus bars. The low voltage transformer includes at least two electrical contacts and a low voltage power receptacle. The electrical contacts engage the respective electrical bus bars, and the low voltage transformer is operable to transform or convert the line voltage received at the electrical contacts to a lower voltage output at the low voltage power receptacle. 
     In one aspect, the housing is a two-piece housing including a front housing piece and a rear housing piece. The front housing piece defines an opening that is aligned to permit access to the low voltage power receptacle by an electrical connector associated with an electrical consumer. 
     In another aspect, the low voltage power receptacle assembly includes a coupler portion disposed at an end portion of the electrical bus bars for engaging an electrical connector that is in electrical communication with a power supply. The electrical connector is thus configured to be electrically connected to the electrical bus bars at the coupler portion. Optionally, the housing defines the coupler portion. 
     In yet another aspect, the receptacle assembly further includes a second coupler portion at an opposite end of the electrical bus bars from the first coupler portion, and configured to engage a second electrical connector that is in electrical communication with a high voltage power outlet receptacle configured to carry the line voltage. The second electrical connector can thus be electrically connected to the electrical bus bars at the second coupler portion. 
     In a further aspect, the electrical bus bars include a hot bus bar and a neutral or ground bus bar. Optionally, the electrical contacts of the low voltage transformer include a hot electrical contact and a neutral or ground electrical contact. Optionally, the neutral or ground bus bar includes a neutral bus bar, the low voltage power receptacle assembly further including a ground bus bar spaced from the hot bus bar and from the neutral bus bar, and wherein a second elongate space is defined between the ground bus bar and at least one of the hot bus bar and the neutral bus bar. 
     In still another aspect, the isolator body includes a second elongate non-conductive wall disposed in the second elongate space. 
     In a still further aspect, each of the electrical contacts of the low voltage transformer is positioned between one of the elongate non-conductive walls and a respective one of the electrical bus bars. Optionally, the at least two electrical contacts include compressible resilient contacts, and each of the at least two electrical contacts is compressed between one of the elongate non-conductive walls and the respective one of the electrical bus bars. 
     In another aspect, one of the at least two electrical bus bars includes a hot bus bar having a first or second configuration, and the housing and the isolator body are configured to receive the hot bus bar in either of the first and second configurations. 
     In a further aspect, the at least two electrical contacts of the low voltage transformer include first, second, and third electrical contacts, the first and second electrical contacts including hot contacts and the third electrical contact including a neutral or ground contact. In this arrangement, the first electrical contact is configured to electrically engage the hot bus bar in the first configuration while the second electrical contact remains electrically isolated, and the second electrical contact is configured to electrically engage the hot bus bar in the second configuration while the first electrical contact remains electrically isolated. 
     Optionally, the line voltage is about 110V AC or about 220V AC, and wherein the lower voltage output at the low voltage power receptacle is between about 2V DC and about 12V DC. The low voltage power receptacle may be a USB receptacle and, optionally, the power receptacle assembly may include a high voltage AC power receptacle. 
     Thus, the low voltage power receptacle assembly of the present invention provides convenient access to low voltage power, such as may be used for charging and/or providing power to low voltage electrical consumers, such as mobile phones, computers, and computing devices, digital cameras, communications equipment, etc., in a manner that presents a finished appearance, and in a modular system that also permits reconfiguration and/or customization of the various high voltage and low voltage receptacles that may be provided within the system. Users are thus provided with access to low voltage charging or power outlets such as USB-style outlets, without need for separate low voltage wiring systems in addition to a separate high voltage power system. 
     These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a low voltage power receptacle in accordance with the present invention, shown coupled to a modular electrical system in a raceway; 
         FIG. 2  is a front perspective view of the low voltage power receptacle of  FIG. 1 , as viewed from a downstream end thereof; 
         FIG. 3  is another front perspective view of the low voltage power receptacle of  FIG. 2 , as viewed from an upstream end thereof; 
         FIG. 4  is a rear perspective view of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 5  is a bottom plan view of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 6  is a left side elevation of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 7  is an upstream end elevation of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 8  is a top plan view of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 9  is a downstream end elevation of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 10  is a right side elevation of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 11  is an exploded perspective view of the low voltage power receptacle of  FIG. 2 , as viewed from a downstream end thereof; 
         FIG. 11A  is a wire diagram of low voltage transformer circuitry associated with the low voltage power receptacle; 
         FIG. 12  is a partially exploded perspective view of the low voltage power receptacle of  FIG. 2 , as viewed from a downstream end thereof; 
         FIGS. 12A and 12B  are enlarged views of the areas designated XIIA and XIIB, respectively, in  FIG. 12 ; 
         FIG. 13  is another partially exploded perspective view of the low voltage power receptacle of  FIG. 2 , as viewed from an upstream end thereof; 
         FIG. 13A  is an enlarged view of the area designated XIIIA in  FIG. 13 ; 
         FIG. 14  is a simplified wire diagram showing electrical connections of the low voltage power receptacle of  FIG. 2 ; 
         FIG. 15  is another top plan view of the low voltage power receptacle of  FIG. 2 , with electrical bus bars shown in phantom; 
         FIGS. 16A-16D  are perspective views of various electrical cables and connectors that form portions of a modular electrical system that can incorporate the low voltage power receptacle; 
         FIG. 17  is a perspective view of the low voltage power receptacle shown coupled to a portion of a modular electrical system; and 
         FIGS. 17A and 17B  are enlarged views of the areas designated XVIIA and XVIIB, respectively, in  FIG. 17 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A low voltage power receptacle assembly is provided for use within a modular electrical system, which is configurable to provide both high voltage line power (e.g., 110V AC or 220V AC) electrical power at standard power receptacles, while also providing low voltage power (e.g., 2V DC to 12V DC) within the same modular electrical system, which may be incorporated into raceways or other areas to provide electrical power in work areas or the like. As will be described in more detail below, the modular electrical system may be configured, reconfigured, and customized to provide a desired number of both high and low voltage outlets within a desired area, and may even incorporate or accommodate two or more circuits to increase the capacity of the system. 
     Referring now to the drawings and the illustrative embodiments depicted therein, a low voltage power receptacle assembly  10  is configured for installation in a modular electrical system  12 , which may be routed through one or more raceways  14 A,  14 B within an area such as a work space defined by walls  16 , such as shown in  FIG. 1 . Power receptacle assembly  10  includes a two-piece housing  18  having a front housing piece  18 A and a rear housing piece  18 B, such as shown in  FIGS. 2-4 ,  11 ,  12 , and  13 . Housing  18  defines an internal cavity  20  between internal surfaces of front housing piece  18 A and rear housing piece  18 B, such as shown in  FIG. 11 . Cavity  20  receives other components of receptacle assembly  10 , including a plurality of electrical bus bars  22 , a low voltage transformer or transformer assembly  24 , and an isolator body  26  ( FIGS. 11 ,  12 , and  13 ). As will be described in more detail below, low voltage transformer  24  receives electrical power from electrical bus bars  22 , which carry line voltage, typically 110V AC or 220V AC, and converts the high voltage power to a low voltage output at at least one low voltage receptacle  28 , while isolator body  26  isolates bus bars  22  from one another and from low voltage circuitry, and also helps to ensure sufficient electrical contact between low voltage transformer  24  and the electrical bus bars  22 . 
     Housing  18  includes a power input coupler portion  30   a  and a power output coupler portion  30   b , such as shown in  FIGS. 2-10 , and may be made from molded resinous plastic, for example, or any other suitable material. Front housing piece  18   a  and rear housing piece  18   b  cooperate to define the power input and power output coupler portions  30   a ,  30   b , and in the illustrated embodiment, the housing pieces are secured together via a plurality of engagement members, which include four main engagement tabs  32   a  and four coupler-end hook portions  32   b  that are integrally or unitarily formed with rear housing piece  18   b  ( FIGS. 11 ,  12 , and  13 ). Front housing piece  18   a  includes four main hook portions  34   a , and four coupler-end receiving portions  34   b , which receive coupler-end hook portions  32   b  of rear housing piece  18   b . Coupler-end hook portions  32   b  snap into engagement with coupler-end receiving portions  34   b , while main engagement tabs  32   a  of rear housing piece  18   b  engage respective recess areas  36  formed in front housing piece  18   a  ( FIGS. 11 ,  12 , and  13 ), and main hook portions  34   a  of front housing piece  18   a  engage hook-receiving surfaces  38  of rear housing piece  18   b , such as also shown in  FIGS. 2-6 ,  8 , and  10 - 13 A. 
     Power input coupler portion  30   a  and power output coupler portion  30   b  may be substantially similar or substantially identical to couplers that are shown and described in commonly-owned and co-pending U.S. patent application Ser. No. 13/647,992, filed Oct. 9, 2012 (U.S. Publication No. 2013/0095681), which is hereby incorporated herein by reference in its entirety. In the illustrated embodiment, front housing piece  18   a  defines two generally rectangular openings  40  that provide access to respective receptacle openings  42  of low voltage receptacle  28 . Optionally, an indicia marking  44  may be provided on front housing piece  18   a , near rectangular openings  40 , to inform users of the type of power and/or connectors that are provided at receptacle assembly  10 . 
     Electrical bus bars  22  include a neutral bus bar  22   a , a ground bus bar  22   b , and one of two possible “line” or “hot” bus bars  22   c  and  22   d , such as shown in  FIG. 11 . Each of the electrical bus bars  22  has a pair of opposite end portions, including an input end portion  46  and an output end portion  48 , which are housed in power input coupler portion  30   a  and power output coupler portion  30   b  of housing  18 , respectively, such as shown in  FIGS. 7 ,  9 ,  11 ,  12 ,  13 , and  17 A. Located between input end portions  46  and output end portions  48  of bus bars  22  are respective laterally outwardly-extending middle portions  50  that cooperate to define a generally rectangular open space  52  between the respective middle portions  50  of ground bus bar  22   b  and either first hot bus bar  22   c  and second hot bus bar  22   d , whichever is present ( FIG. 11 ). In the event that both first and second bus bars  22   c ,  22   d  are present, then the open space  52  would be defined between the respective middle portions  50  of ground bus bar  22   b  and second hot bus bar  22   d , the latter being located inboard of first hot bus bar  22   c , such as shown in  FIGS. 12 and 13 . Rectangular open space  52  provides clearance for various electrical components of low voltage transformer  24 , which will be described in more detail below. 
     First hot bus bar  22   c  and second hot bus bar  22   d  are illustrated using phantom lines in  FIGS. 11 and 14  to denote that, optionally, one of the first and second hot bus bars  22   c ,  22   d  could be omitted in a given low voltage power receptacle assembly  10 . First hot bus bar  22   c  is functionally identical to second hot bus bar  22   d , and differs only in that (1) first hot bus bar  22   c  is shaped for positioning at a more inboard location (and may be substantially identical in shape to ground bus bar  22   b , but arranged in a mirror-image thereto), and (2) the use of first hot bus bar  22   c  would supply electrical current to the receptacle assembly  10  via a first circuit associated with input end portion  46  of first hot bus bar  22   c , while the position of second hot bus bar  22   d  would associate it with a second circuit, such as shown in  FIG. 15 . Second hot bus bar  22   d  may be substantially identical in shape to neutral bus bar  22   a , but arranged in a mirror-image thereto. 
     Although both first hot bus bar  22   c  and second hot bus bar  22   d  are illustrated using solid lines in  FIGS. 7 ,  9 ,  12 ,  13 ,  17 , and  17 A, which may be a standard arrangement, it will be appreciated that this arrangement is merely exemplary, and only one of the hot bus bars  22   c ,  22   d  would be needed in the receptacle assembly for it to function properly. It is envisioned that both hot bus bars  22   c ,  22   d  could be included, and either or both could be electrically energized, while still permitting the low voltage power receptacle assembly  10  to function in a desired manner, such as by providing a suitably-adapted low voltage transformer. When both hot bus bars  22   c ,  22   d  are included, the hot bus bars are electrically isolated from one another in circuitry  51  ( FIG. 11A ) that is associated with low voltage transformer assembly  24 . Circuitry  51  includes a pair of separate diode bridges, including a first diode bridge  53   a  associated with first hot bus bar  22   c  and neutral bus bar  22   a , and a second diode bridge  53   b  associated with second hot bus bar  22   d  and neutral bus bar  22   a.    
     Isolator body  26  includes three separate upstanding walls or wall portions, including an inboard generally rectangular wall portion  54  and a pair of separate and generally U-shaped outboard wall portions  56   a ,  56   b , such as shown in  FIG. 11 . Inboard rectangular wall portion  54  defines a generally rectangular opening  58  and has a pair of opposite longitudinally-extending wall projections  60 . Outboard wall portions  56   a ,  56   b  have elongate middle regions that are spaced from (and substantially parallel to) corresponding longitudinal walls of inboard rectangular wall portion  54 , with elongate longitudinal gaps or spaces  62  defined between the middle regions of outboard wall portions  56   a ,  56   b  and the corresponding longitudinal wall portions of inboard rectangular wall portion  54 . 
     At opposite ends of each outboard wall portion  56   a ,  56   b  is a respective laterally-inwardly directed wall end portion  64 , which is spaced longitudinally from (and generally parallel to) respective lateral end walls of inboard rectangular wall portion  54 . Wall end portions  64  terminate at respective locations that are spaced laterally outwardly from the wall projections  60  of inward rectangular wall portion  54 , and are spaced from the lateral end walls of inboard rectangular wall portion  54  in order to form channels  66  with open ends defined between wall projections  60  and wall end portions  64 , and which are contiguous with respective elongate spaces  62 . A generally planar flange or mounting portion  68  extends laterally outwardly from outboard wall portions  56   a ,  56   b , and is received in rear housing piece  18   b  during assembly. Flange portion  68  is formed with notches  70  in its opposite ends ( FIG. 11 ), which provide clearance for respective electrical contacts  72   a - c  of low voltage transformer  24 . Flange portion  68  may be unitarily formed with inboard rectangular wall portion  54  and outboard wall portions  56   a ,  56   b , and is made of a non-conductive material, such as injection molded resinous plastic or the like. 
     Elongate spaces  62  and channels  66  are configured or shaped to receive respective ones of the ground bus bar  22   b  and first hot bus bar  22   c , while outboard wall portion  56   a  defines a first outboard channel  74   a  between itself and a first side wall  76   a  of rear housing piece  18   b , and outboard wall portion  56   b  cooperates with a second side wall  76   b  of rear housing piece  18   b  to define a second outboard channel  74   b . First outboard channel  74   a  is configured to receive second hot bus bar  22   d , while second outboard channel  74   b  is configured to receive neutral bus bar  22   a , such as shown in  FIGS. 12-12B . 
     Low voltage transformer  24  includes a substantially planar base  78  to which various electrical components are mounted, including electrical contacts  72   a - c , low voltage receptacle  28 , a low voltage switching power supply transformer  80 , power input capacitors  82 , and power output capacitors  84 . Neutral electrical contact  72   a  and one of first hot electrical contact  72   b  and second hot electrical contact  72   c  bring high voltage electrical power (typically 110V AC or 220V AC current) to low voltage transformer  24  from an electrical power source. From the electrical contacts, the high voltage power is passed through power input capacitors  82 , which filter the high voltage power before passing it along to low voltage switching power supply transformer  80 . Transformer  80  is operable to transform the high voltage power input to an unfiltered low voltage output, such as about 2V DC to about 12V DC. The unfiltered low voltage output is then passed through power output capacitors  84 , which are operable to filter the power from transformer  80  and supply the filtered low voltage power output to low voltage receptacle  28 , where users may access the low voltage power by coupling a cable or device to one of receptacle openings  42 . 
     In the illustrated embodiment, transformer  80  is a USB switching power supply transformer with a low voltage output of about 5V DC, although it will be appreciated that substantially any suitable electrical transformer may be used without departing from the spirit and scope of the present invention. In addition, the low voltage receptacle  28  of the illustrated embodiment is a USB power receptacle with socket-style USB receptacle openings  42  housing respective electrical contacts as is known in the art, but it is envisioned that substantially any type of low voltage receptacle, terminals, or coupling may be used. 
     Referring now to  FIGS. 10 ,  11 , and  12 , low voltage receptacle  28 , low voltage switching power supply transformer  80 , power input capacitors  82 , and power output capacitors  84  are positioned along a top or front surface of base  78 , and are mounted in sufficiently close proximity to one another that they are positionable within the generally rectangular opening  58  formed in isolator body  26 , as well as within the generally rectangular opening or space  52  formed between the arrangement of electrical bus bars  22 . However, electrical contacts  72   a - c  are all positioned outside of inboard rectangular wall portion  54  and, thus, outside of rectangular opening  58 . Neutral electrical contact  72   a  is also positioned outside of ground bus bar  22   b  and, thus, outside of the rectangular opening  52 . 
     Electrical contacts  72   a - c  are made of resilient metal with spring-like properties, and may be substantially similar to the electrical contacts that are commonly used to electrically and mechanically engage the positive and negative terminals of electrical cells (“batteries”) in portable electronic devices or other devices that use replaceable batteries. Electrical contacts  72   a - c  are arranged or positioned along base  78  so that when first hot bus bar  22   c  and second hot bus bar  22   d  are both installed, then first hot electrical contact  72   b  will be partially compressed between the inboard surface of first hot bus bar  22   c  and the outboard surface of inboard rectangular wall portion  54  ( FIG. 13A ), thereby making an electrical connection to first hot bus bar  22   c , while second hot electrical contact  72   c  will be partially compressed between the inboard surface of second hot bus bar  22   d  and the outboard surface of outboard wall portion  56   a  ( FIG. 12A ), thereby making an electrical connection to second hot bus bar  22   d.    
     In the event that first hot bus bar  22   c  is installed and second hot bus bar  22   d  is not installed, first hot electrical contact  72   b  is partially compressed between an inboard surface of first hot bus bar  22   c  and an outboard surface of inboard rectangular wall portion  54  ( FIG. 13A ), thereby making an electrical connection to first hot bus bar  22   c , while second hot electrical contact  72   c  remains electrically isolated (i.e., no electrical contact is made between contact  72   c  and any bus bar  22 , although this arrangement is not shown in  FIG. 12A ). 
     In contrast, when first hot bus bar  22   c  is not installed and second hot bus bar  22   d  is installed, first hot electrical contact  72   b  remains electrically isolated (i.e., no electrical contact is made between contact  72   b  and any bus bar  22 , although it should be noted that this arrangement is not shown in  FIG. 13A ), while second hot electrical contact  72   c  is partially compressed between an inboard surface of second hot bus bar  22   d  and an outboard surface of outboard wall portion  56   a  ( FIG. 12A ), thereby making an electrical connection to second hot bus bar  22   d.    
     Regardless of whether one or both of first hot bus bar  22   c  and second hot bus bar  22   d  are included in the low voltage power receptacle assembly  10 , neutral electrical contact  72   a  is at least partially compressed between an inboard surface of neutral bus bar  22   a  and an outboard surface of outboard wall portion  56   b , thereby making an electrical connection to neutral bus bar  22   a . In the illustrated embodiment, no electrical connections are made to ground bus bar  22   b  by low voltage transformer assembly  24 , although it is envisioned that such a connection could readily be made, if desired, in a substantially similar manner as described above for making electrical connections to neutral bus bar  22   a , first hot bus bar  22   c , and second hot bus bar  22   d.    
     Thus, with electrical bus bars  22  installed at isolator body  26 , which in turn is installed at low voltage transformer assembly  24 , which in turn is installed at rear housing piece  18   b , each electrical bus bar  22   a - d  is received in a respective channel or space ( 62 ,  66 ,  74   a ,  74   b ) defined between two adjacent upstanding walls ( 54 ,  56   a ,  56   b ,  76   a ,  76   b ), thus ensuring that electrical bus bars  22  remain electrically insulated and/or isolated from one another as they pass through cavity  20  of housing  18 . Electrical connections made between electrical contacts  72   a - c  and respective ones of the electrical bus bars  22   a ,  22   c ,  22   d  are also made in the electrically isolated channels between non-conductive walls, thus ensuring electrical isolation where the electrical connections are made. 
     To further ensure adequate electrical isolation, housing front piece  18   a  and housing rear piece  18   b  both include a plurality of inboard separation or divider walls  86  and a further plurality of outboard separation or divider walls  88  at the opposite end portions thereof, which cooperate to form power input coupler portion  20   a  and power output coupler portion  30   b  of low voltage power receptacle assembly  10 . 
     As noted above, low voltage power receptacle assembly  10  in configured to be mounted in a modular electrical system such as that indicated at reference numeral  12  in  FIG. 1 , and to carry high voltage power to other areas of the system that utilize high voltage power, while simultaneously utilizing the high voltage power to provide a low voltage receptacle in the modular electrical system. It is envisioned that the low voltage power receptacle assembly of the present invention may be compatible for use in substantially any high voltage electrical system, including being adaptable for use in hard-wired or non-modular systems, without departing from the spirit and scope of the present invention. 
       FIGS. 16A-17B  show various subcomponents or subassemblies of modular electrical systems, in order to illustrate various installation applications for low voltage power receptacle assembly  10 . For example, in  FIG. 16A , a power receptacle assembly  10  is electrically coupled to a four-wire junction block  86  via a two-way, four-wire connector  88 . When the power receptacle assembly  10  and the four-wire junction block  86  are supplied with high voltage electrical power from a power source  89  ( FIG. 1 ), junction block  86  provides access to the high voltage electrical power while low voltage power receptacle assembly  10  simultaneously provides access to low voltage electrical power. 
     Optionally, and as shown in  FIG. 16B , the power receptacle assembly may be coupled to a two-way, four-wire jumper cable assembly  90  having a pair of two-way, four-wire connector blocks  92  at its opposite ends, the connector blocks  92  being optionally connectable to a four-way, four-wire connector  94 . In  FIG. 16C , a power receptacle assembly  10  is arranged for connection to a three-way, four-wire jumper cable assembly  96  having a two-way, four-wire connector block  92  at one end for connection to power receptacle assembly  10 , and further having a three-way, four-wire male/female jumper cable assembly connector block  98 , including a female end connector portion  100  and a male end connector portion  102 . Optionally, and as shown in  FIG. 16D , another two-way, four-wire jumper cable assembly  90  is arranged for coupling one of its two-way, four-wire connector blocks  92  directly to a four-wire junction block  86 , which can in turn be coupled to low voltage power receptacle assembly  10  via a two-way, four-wire connector  88 , such as shown in  FIG. 17 . The various connectors and cables shown in FIGS.  1  and  16 A- 17 B are more fully described in commonly-owned and co-pending U.S. patent application Ser. No. 13/647,992, filed Oct. 9, 2012 (U.S. Publication No. 2013/0095681), which is hereby incorporated herein by reference in its entirety. 
     While low voltage power receptacle assembly  10  is shown and described as being compatible for use in a two-circuit electrical system, it will be appreciated that the principles of the present invention may be adapted for single-circuit systems, or electrical systems having three or four or more electrical circuits, simply by scaling the low voltage power receptacle assembly as needed to accommodate the desired number of circuits, without departing from the spirit and scope of the present invention. It will further be appreciated that the specific arrangement or type of connectors may be adjusted as desired for substantially any application, or the receptacle assembly may be readily adapted for use in a non-modular system. 
     Optionally, and as shown in  FIG. 14 , a low voltage power receptacle unit may also include a high voltage power receptacle  104  (such as a 110V AC or 220V AC simplex receptacle), with receptacle openings  106   a - c  in a standard configuration and with respective conductors  108   a - c  electrically coupled to neutral bus bar  22   a , ground bus bar  22   b , and either first bus bar  22   c  or second bus bar  22   d . This arrangement would provide users with access to both a standard high voltage power receptacle and one or more low voltage receptacles at the same power receptacle unit. Additional space and/or non-conductive isolation walls or the like may be provided so that there is sufficient packaging room for the additional receptacle, and to provide appropriate separation between high and low voltage conductors. 
     Accordingly, the low voltage power receptacle assembly of the present invention provides one or more low voltage power receptacles having a clean and permanent-looking appearance, such as in a work area, public space, or the like, without need for a low voltage wiring system that would be separate or distinct from a high voltage wiring system that may serve the same area. When incorporated into a modular electrical system that can be configured, reconfigured, and customized according to the needs of a particular area or user, the low voltage power receptacle assembly can be used to provide substantially any desired number of low voltage outlets in the same general area as high voltage outlets, and may even be installed in modular electrical systems having two or more electrical circuits. 
     Changes and modifications in the specifically-described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents.