- 1 POWER CHARGER The present invention relates to a power charger and, in particular, to a power charger for a mobile device. 5 Recently, mobile devices have increasingly used Universal Serial Bus (USB) connections to connect to power supplies for charging and powering purposes. USB is particularly attractive for mobile devices since the connector includes 10 power contacts, to charge and power the device, and also data contacts, to transfer data between the mobile device and the unit to which it is connected, for example a laptop computer. 15 There are two main types of USB ports for charging or powering devices via USB. The first of these is a Charging Downstream Port (CDP). CDP supports data transfer as well as carrying power. In order not to interfere with high speed data transfer, typically, CDPs 20 limit the current on the power contacts to around 900mA during data transfer. The second type of USB charging port is a Dedicated Charging Port (DCP). Dedicated Charging Ports only provide power and do not carry data. DCPs can provide larger current across the power contacts 25 due to the fact that no data is being transferred and so interference is not a problem. DCPs can provide current of up to 2000mA. Higher current allows the batteries of the device to charge more quickly. 30 With mobile devices continually including more power hungry applications, access to charging points and speed of charging is becoming important. Long recharge periods may be acceptable to consumers in certain situations, for example where the device can recharge overnight, but if a 35 consumer needs to recharge a device during the day he will require the recharge to take place quickly. Consequently, higher current is becoming increasingly import and DCPs - 2 are becoming more attractive for recharge purposes. Summary of the Invention In accordance with an aspect of the present invention, 5 there is provided an electrical power supply unit comprising a transformer having an input connected to a mains power supply and an output connected to a power connector port, wherein the power connector port is remote from the transformer. 10 Preferably, the transformer is suitable for converting power from mains power specifications to a power specification suitable for charging a mobile device. 15 Preferably, a terminating unit houses the transformer, the terminating unit configured to contain heat generated by the transformer. Preferably, the power connector port comprises at least 20 one Universal Serial Bus connector. Preferably, the power connector port is connected to the transformer via an electrical cable, the cable having length of around 30 cm. 25 Preferably, the power connector port is suitable for connection to a standard power supply plate. In a second aspect, the invention provides an electrical 30 power supply for a Universal Serial Bus connector comprising a transformer having an input adapted to be connected to mains wiring and an output for providing power to a Universal Serial Bus connector, the Universal Serial Bus connector adapted to be incorporated into a 35 power plate, the Universal Serial Bus connector being remote from the transformer.
- 3 Preferably the power plate is surface mounted. Preferably the transformer is adapted to be positioned within a wall cavity. 5 Preferably the Universal Serial Bus connector is adapted to be connected into a standard size receptacle in a power plate. 10 Preferably the transformer is suitable for converting mains power to USB power specifications. Preferably the transformer is suitable for converting power from mains power specifications to a power level 15 suitable for charging a mobile communication device. Preferably the electrical power supply comprises a terminating unit for housing the transformer, the terminating unit configured to contain heat generated by 20 the transformer. Preferably the power connector port is connected to the transformer via an electrical cable, the cable having length of around 30 cm. 25 Preferably the USB connector includes at least one USB receptacle providing power at 2.1 A. Preferably the power plate is a general power output (GPO) 30 plate, switch plate, lighting plate or an electrical accessory plate. Preferably the transformer input is adapted to be connected to the mains wiring at the power plate. 35 In a third aspect the invention provides a power system comprising a power plate; at least one Universal Serial - 4 Bus connector incorporated into the power plate; a transformer having an input connected to mains wiring and an output connected to the at least one Universal Serial Bus connector, the transformer being remote from the at 5 least one Universal Serial Bus connector. Preferably the transformer is suitable for converting mains power to USB power specifications. 10 Preferably the Universal Serial Bus connector comprises at least two USB receptacles each delivering around 2.1 A. Preferably the transformer input is connected to mains wiring at the power plate. 15 In a fourth aspect the invention provides a method for delivering power to a USB receptacle on a power plate comprising connecting at least one Universal Serial Bus receptacle to the power plate; connecting a transformer 20 input to mains wiring and connecting a transformer output to the at least one Universal Serial Bus receptacle, the transformer being remote from the at least one Universal Serial Bus receptacle. 25 Description of the Drawings The present invention will now been described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a first embodiment of a twin USB charger in 30 accordance with an embodiment of the present invention; Figure 2 is a face view of the connector showing the twin USB receptacles; Figure 3 shows the face of a double power socket incorporating a twin USB receptacle in accordance with an 35 embodiment of the present invention; Figure 4 shows the USB charger unit installed and connected to a device for charging; and - 5 Figure 5 shows the components of a USB power charger in accordance with an embodiment of the present invention. Figure 6 shows connections to a general power output wall plate. 5 Figure 7 shows connections to a general power output wall plate. Description Referring to the drawings, there is shown a terminating 10 unit 10 for connection to a mains power supply. The mains power supply may be the power supply installed in a residence or office and, typically, will be provided with a live, neutral and earth connection within standard rating cabling. The terminating block 10 houses a 15 transformer to convert the voltage and current of the mains supply to that suitable for charging mobile device via USB. Transformer 20 (shown in Figure 5) is housed within the terminating block 10. The terminating block 10 includes a wiring connection block 30 to facilitate 20 connection from the mains wiring to the transformer. The terminating unit has a power output 40 for providing power to USB connector 60. The power leads contained within cable 50 are connected to the output of the 25 transformer 20. Cable 50 is connected to a twin USB connector 60. The twin USB connector includes two USB receptacles 62 and 64 shown in Figure 2. The terminating unit is preferably made from heat 30 resistant plastic in order to safely manage and contain heat generated by the transformer. The terminating unit is designed with a suitable form factor to allow connection onto a surface or to be 35 contained within a wall cavity. For example, embodiments may include receptacles for fastening means, for example screws, to provide attachment of the terminating unit to a -6 surface. In further embodiments, the terminating connections 30 may be contained within the terminating unit in order that the 5 connections between the mains cabling and the transformer are contained within the terminating unit. Such embodiments are particularly advantageous because no wiring is left exposed which increases the safety of the unit. 10 The output from the transformer can be selected in dependence on the power delivery requirements for various devices. Preferably, in order to provide power for devices through a USB the power output from the 15 transformer is provided in the form of a 5 volt output and a current of 2000mA. In the embodiment of Figure 1, the power output from the transformer is split to provide two USB power connections via USB receptacles 62 and 64 within connection unit 60. 20 The form factor of USB connector 60 is suitable to be incorporated into a power socket plate. Figure 3 shows a standard power socket plate 310 incorporating twin USB receptacles. 25 In the embodiment of Figure 3, the plate is configured to simultaneously receive two separate power plugs at power connections 320, 310 along with two separate USB plugs USB connector 360. On the reverse side of the plate, the USB 30 connector 360 does not interfere with the wiring into the power connectors 320, 310 due to its small form factor. Instead, simply USB connector 360 and USB cabling 50 protrudes from the rear side of the plate to the larger terminating unit including the transformer. This 35 configuration enables the terminating unit and transformer to be located sufficiently far from the plate so as not to interfere with any of the cabling or connections to the -7 plate itself. The embodiments of the invention facilitate easy and safe installation since there is no exposed wiring at the 5 reverse side of the plate for the USB power charger and no electrical connections are made to the power plate for the USB connections, these are made within the USB connector and completed before presenting the connector to the plate. Instead the connector is simply fitted into the 10 plate. All electrical connections to the USB receptacles are pre-connected and housed within the USB connector. Additionally, the terminating unit contains any heat generated from the transformer so as not to interfere with 15 any other components or wiring for the power plate. Figure 4 shows a representative example of an embodiment of the USB power charger installed into a wall cavity and connected to a power plate. The transformer is correctly 20 configured to convert mains power specifications to USB power specifications. In installation, the engineer can pull the mains power lead 405 through wall cavity 420 and connect the mains power cables to the terminating block housing the transformer. Preferably, terminating unit 410 25 and transformer are pre-connected to the USB connector 440. Once the connection between the mains and the transformer are made, the USB connector 440 is fixed into the power plate 430. The terminating unit 410 is then fed through the wall cavity 420 and fixed in position using 30 attachments. Power plate is fixed over the wall cavity as usual. As shown in Figure 4, devices can be connected to the USB connectors on the power plate. It is clear from Figure 4 35 that the terminating unit is located remotely from USB connector. Since the terminating unit is remote from the USB connector it does not interfere structurally with any - 8 power plate wiring. Instead, the USB connector connects directly to the power plate. In typical embodiments of the invention the cabling 50 has 5 sufficient length to enable the transformer to be placed away from the power plate and attached to a surface. Typical lengths for cables are around 30 cm. Figure 6 shows a further embodiment of a USB connector 10 connected to a power plate. In Figure 6 the USB connector is connected to double general power output (GPO) plate 600. The GPO includes a receptacle 610 for receiving USB connector 620. In Figure 6b USB connector 620 is inserted into the receptacle of power plate 600. In the embodiment 15 of figure 6b USB connector 620 includes a clipping mechanism to retain USB connector in the receptacle. Alternatively, other attachment mechanisms could be used for attaching the USB connector to double GPO plate 600. 20 Figure 6c shows the power connections in and out of the double GPO plate 600. Mains wiring 630 is terminated onto terminals 602 604 602 on the rear side of double GPO plate 600. Power to USB transformer 640, housed within housing 640, is provided from double GPO plate 600. The Active 25 (live) wire 632 from mains wiring is connected to Active terminal 602 on the rear side of double GPO plate 600. The Neutral wire 634 from mains wiring is connected to Neutral terminal 604 on the rear side of the double GPO plate 600. The Earth wire 636 from the mains wiring is 30 connected to the Earth terminal 606 on the rear side of double GPO plate 600. USB transformer is housed within housing 640. USB transformer includes active input provided by active wire 35 642 and a neutral input provided by neutral wire 644. The active wire 642 and neutral wire 644 are contained within cabling 660. In the embodiment of Figure 6, the active - 9 wire 642 and neutral wire 644 are terminated to the transformer within transformer housing 640. To provide mains power input to the transformer active 5 wire 642 is connected to active terminal 602 on the double GPO plate 600 and neutral wire 644 is connected to neutral terminal 604 on the double GPO plate 600. Mains power at 230 V is routed from the double GPO plate terminals 602 604 to the transformer and converted to deliver 2.1 mA at 10 5V to each USB receptacle contained within USB connector 620. As discussed above, by positioning transformer away from double GPO plate 600, any heat dissipation in the 15 transformer is located away from the double GPO plate. Additionally, by positioning the transformer away from the double GPO plate there are fewer restrictions on the physical size of the transformer. Larger transformers can be utilised to deliver larger power outputs. 20 Cable tie 650 attached to transformer housing 640 is attached to mains wiring 630 after electrical connections to the terminals of the double GPO plate 600 have been completed. Cable tie 650 is plastic but may also be 25 manufactured from any other suitable material. Alternatively the cable tie may be in the form of a clip or hook or any other form suitable for attaching the transformer housing to mains wiring 630. 30 The cable of mains wiring 630 is thermoplastic sheathed cable (TPS cable) which is typically thicker and stiffer than USB cabling 660. By attaching transformer housing 640 to the mains wiring 630 the mains wiring supports the weight of the transformer without providing undue strain 35 on the electrical connections to double GPO plate 600. During installation mains wiring 630 is pulled through the - 10 wall 670 to facilitate connection of the mains active neutral and earth wires 632 634 636 and transformer power wires 642 644 onto double GPO plate 600. 5 In alternative embodiments the transformer housing 640 is attached to the inside of wall 670 or positioned elsewhere within the wall cavity. Screws or other suitable attachment means can be used to attach transformer housing 640 to the wall. 10 After power connections to and from terminals 602 604 606 of double GPO plate 600 are complete and USB connector 620 is inserted into double GPO plate 600, transformer housing 640 is fed into the wall cavity and double GPO 15 plate 600 is surface mounted to wall 670 using screws or other attachment means as shown in Figure 6e. Transformer housing 640 is sized within the dimensions of double GPO plate 600 to allow it to pass into the all 20 cavity. After installation transformer 640 hangs in the wall cavity behind wall 670 supported by cable tie 650 and mains wiring as shown in Figure 8. Transformer is positioned away from double GPO plate 600 to prevent heat dissipation from the transformer in the vicinity of the 25 double GPO plate. In further embodiments the USB connector and USB receptacles are integral with double GPO plate 600. In such embodiments the connections to and from the USB transformer is prewired to double GPO plate terminals 602 30 604 and the USB connector 620. Such embodiments remove the requirement for the USB connector to be manually inserted into the double GPO plate 600 during installation. Additionally, there is no need to connect the USB transformer wires 642 644 to the terminals 602 604 35 of the double GPO plate 600 during installation. Such embodiments have similar cable lengths to the separate system to provide heat dissipation within the transformer - 11 away from the front plate. Figure 7 shows an alternative embodiment of installation of the USB transformer. In the embodiment of Figure 7 5 mains wiring 710 carrying power at mains specifications, typically at 230 Volts is split at 715. One leg of the split mains wiring is routed to USB transformer within transformer housing 720. USB transformer converts the power input from mains power to 2.1 A at 5 V for 10 connection to twin USB receptacles in connector 730. Output 725 from USB transformer is routed to USB connector 730 on double GPO plate 740. Transformer housing 720 is designed to contain heat dissipated from the transformer, as discussed above. USB connector 730 is inserted into 15 double GPO plate 740. The second leg 745 of the split mains wiring is routed directly to double GPO plate 740. Second leg 745 provides power at mains specifications to two three pin power 20 outputs of double GPO plate 740. In the embodiments above, the power plates are double General Power Output (GPO) plates. However, further embodiments include any electrical accessory plate to 25 which mains wiring is terminated and into which USB receptacles are provided. For example, in further embodiments the power plate is a lighting plate incorporating a switch for controlling lighting units. In a further embodiment the power plate is a designated USB 30 plate including USB receptacles. The mains wiring is wiring installed within a premises and maintained within the walls, ceilings and floors of the premises. Typically mains wiring is connected to the rear 35 side of surface mounted electrical devices including power plates including GPO plates, lighting plates, switch plates or other electrical devices. Mains wiring carries - 12 power at mains power specifications, typically 220 - 240 Volts or 110 to 130 Volts depending on location. It will be clear to those skilled in the art that the configuration of embodiments of the present invention 5 provides versatility in terms of the performance and rating of the transformer, the type of USB connectors, and heat and power ratings of the materials. For example, if power capabilities of USB sockets were to increase, further embodiments of the invention could incorporate 10 different transformers or, indeed, different connection receptacles. Additionally, embodiments of the invention provide good control over the materials used in the terminating unit in order to manage different levels of heat or standard requirements of different safety 15 requirements. The cabling between the terminating unit and the USB connector can also be selected as suitable for the installation needs and safety rating requirements of the building. Additionally, the flexibility of the cabling can be selected in order to meet the requirements 20 of the installation. It will be clear to those skilled in the art that embodiments of the present invention are not limited to use in USB charging systems. Different connectors for 25 different devices can be incorporated into the connection unit. Many power plates are now produced with a standard size receptacle to receive power connectors or, indeed, to be 30 blocked off. Embodiments of the present invention may include single USB receptacles, twin USB receptacles or any other type of USB receptacle or other power connector. A further advantage provided by embodiments of the present 35 invention is that the transformer is remote from the connector. This moves the generation of heat from the vicinity of the power plate and USB receptacle which - 13 increases the safety of the power plate. By removing the large transformer from the locality of the power plate, embodiments of the invention also removes size restrictions and wiring restrictions from the power plate. 5 This makes installation more straightforward at the plate and also removes any physical interference between the transformer itself and other wiring. Modifications and variations as would be apparent to a 10 skilled addressee are deemed to be within the scope of the present invention.