Abstract:
The present invention relates to a method and an arrangement for visual indication of an electrical quantity, being one or several of power, current and/or voltage through a conductor. The arrangement comprises a substantially wire shaped illuminator and a controller which controls at least one illumination characteristic of said illuminator with respect to said electrical feature.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates to a visualisation arrangement, especially formed as a cable or wire surrounding, for visualisation of current and/or power consumption. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electricity is an invisible phenomenon. Usually, the state of the electrical equipment is indicated using some form of illuminator such as LEDs arranged in a housing. The light from the illuminator indicates whether the equipment is on or off. 
         [0003]    U.S. Pat. No. 6,347,172 describes an optically observable cable and a method of manufacturing the same. The optically observable cable includes a conduit for conducting signals and a side-emitting optical fiber disposed on a periphery of the conduit and extending along a length of the conduit, and a cable jacket encapsulating the conduit and the side-emitting optical fiber, wherein the cable jacket is at least partially translucent such that the side-emitting optical fiber is optically exposed through the cable jacket. A method of detecting individual cables from amongst a plurality of signal transmission cables each having a side-emitting optical fiber includes positioning a light source at an interface which houses and end of a cable to be detected, transmitting light from the light source into the interface, and observing light emitted from an axis of a cable to be detected. This invention aims to solve the problem of identifying different cables in a large number of cable structures. 
         [0004]    In the prior art, materials emitting light when an electric current passes through them are well known and used in a wide range of display applications. Typical electroluminescent devices comprise an anode, normally of an electrically light transmitting material, a layer of a hole transporting material, a layer of the electroluminescent material, optionally a layer of an electron transmitting material and a metal cathode. There can be other layers, such as buffer layers and the layers can be combined using mixtures of one or more of the hole transporting material, electroluminescent material and the electron transmitting material. 
         [0005]    For example, WO 03/093394 relates to an electroluminescent device having a layer which emits light in the blue, purple/blue or ultraviolet section of the spectrum and a layer which contains a fluorescent material and optionally a layer comprising one or more color filters so that light emitted by the electroluminescent layer excites the fluorescent material causing light to be emitted at a longer wavelength. 
         [0006]    US 2002/0039666 relates to an electric luminescence fiber, which can be maintained in any desired shape and can be used in wider applications. The invention provides a flexible luminescence substance produced by arranging electrode wires in electric luminescence powder, said electric luminescence substance is coated with thermoplastic resin, thermosetting resin, or UV-setting resin. The coated resin is hardened and stabilized in linear or other desired shape, and the electric luminescence substance inside the coated resin is maintained in the desired shape. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a novel method and arrangement for indicating the level of current and/or power consumption of one or several apparatuses. Mainly, the invention provides an arrangement and method for indicating the load a power cable is exposed to. 
         [0008]    For these reasons, an arrangement is provided for visual indication of an electrical quantity, being one or several of power, current and/or voltage through a conductor. The arrangement comprises a substantially wire shaped illuminator and a controller which is adapted to control at least one illumination characteristic of the illuminator with respect to the electrical feature. Preferably, the wire shaped illuminator is arranged along the conductor. According to one embodiment, the wire shaped illuminator is electroluminescent. According to another embodiment, the wire shaped illuminator is an optical fibre. 
         [0009]    Preferably, the controller is further adapted to measure the electrical quantity and adopt a control signal to control the illuminator. The controller may comprise a processing arrangement and a measuring arrangement and a driver for driving the illuminator receiving control signals from the processing arrangement. 
         [0010]    According to preferred embodiments, the illumination feature is one or several of intensity, colour or frequency. 
         [0011]    The invention also relates to a cord comprising at least one electric wire and an illuminating arrangement, at least partly arranged along extension of said electric wire, said illuminating arrangement having means for illumination when energized. The cord further comprising a substantially translucent coating, covering said wire and illuminating arrangement. According to one embodiment, the illuminating arrangement is electroluminescent wire. According to another embodiment the illuminating arrangement is an optical fibre. The illuminating arrangement indicates current and/or power consuming through said electric wire. 
         [0012]    The invention also relates to a method of visually indicating an electrical quantity, being one or several of power, current and/or voltage through a conductor, the method comprising the steps of energizing a substantially wire shaped illuminator and controlling at least one illumination characteristic of said illuminator with respect to said electrical feature. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    In the following, the invention will be further described in a non-limiting way with reference to the accompanying drawings in which: 
           [0014]      FIG. 1  schematically illustrates a part of an arrangement according to a preferred embodiment of the invention in perspective, 
           [0015]      FIG. 2  is a cross sectional view through a cord arrangement of  FIG. 1  along line  2 - 2 , 
           [0016]      FIG. 3  is a schematic illustration of a cord, according to the invention, connected to a distributor, and 
           [0017]      FIG. 4  is an exemplary block diagram of a controlling arrangement. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0018]      FIGS. 1 and 2  illustrate an exemplary embodiment of the invention comprising a cord arrangement  10  including three ordinary electrical wires  11 ,  12  and  13  arranged around a centre axis. The electrical wires may extend parallel to the centre axis, as shown in  FIG. 1 , but may also be arranged in a twisted configuration around the centre axis. According to the present example, the three wires may be arranged as power, ground and neutral. The invention can be realised by twisting a number of illuminating wires  14 ,  15  and  16 , which include conductors  141 ,  151  and  161  coated by an illuminating coating  142 ,  152  and  162 , respectively. 
         [0019]    The illuminating wires may be of the type known as electroluminescents, such as described in US 2005037233, WO 031/05538, US 2004067387, WO 03/093394, US 2002/0039666, U.S. Pat. No. 5,485,355 etc. The illuminating wires may also comprise of wires manufactured under trademark Lytec® by ELAM ltd. 
         [0020]    The illuminating wires may also comprise optical fibres, preferably side-emitting optical fibres. 
         [0021]    The twisted electrical wires and illuminating wires are covered by a light transparent or semi transparent coating  18 , for example made of silicon, rubber etc. 
         [0022]    It is appreciated by a skilled person that the present invention is not limited to three illuminating wires and the invention may be applied using any number of illuminating wires and/or electrical wires. 
         [0023]      FIG. 3  illustrates one application of the invention as a cord  30  of a distributor  31 . The distributor  31  is connected to a wall socket  32 . An electric equipment (not shown) is connected to the distributor through a plug  33 . The cord is provided with the illuminating wires as mentioned earlier. It is also possible to provide the distributor and the wall plug itself with illuminating wires and consequently using them as part of the indicator. 
         [0024]    The illuminating wires are connected to a controlling arrangement  34 , in this case arranged inside the distributor. 
         [0025]    An exemplary controlling arrangement is described in the following in conjunction with the block diagram of  FIG. 4 . 
         [0026]    Power to the controlling arrangement  40  is supplied through a power supply  41 , which is connected to, for example, a wall socket through the cord  30 . The power is adapted to the power level of the electronics in the controlling arrangement. The power supplier converts the power from AC to DC. A processing unit  42 , such as a micro computer is arranged to process the information on power level or current amount received from a measuring arrangement  43 . 
         [0027]    The measuring arrangement  43  is arranged between the wall socket and before connection to an electric equipment so that the power and/or current consumption can be measured. The measuring arrangement may sample current and voltage cautiously and provide data to the micro computer. The power is product of current multiplied with voltage. In the event of stable voltage, the phase shift can be ignored and the current can be measured and used to approximate the power. Thus, the difference between the visualisation of current consumption and power consumption can be minimized. 
         [0028]    The micro computer controls, in this example, three pulse width modulators (PWMs)  44   a - 44   c  for controlling analog circuits with a processor&#39;s digital outputs. The number of PWMs corresponds to the number of illuminating wires. The PWMs are connected to drivers  45   a - 45   c,  which operate in a suitable range, e.g. 0-110 V, 8 KHz. The illuminating wires are connected to the drivers and thus operate in the output range of the inverter modules. The drivers may be inverter modules. 
         [0029]    In case of optical fibers, the drivers may be connected to intensity and/or pulse controlled light sources, such as light emitting diodes (LED) connected to one end of the fibers. 
         [0030]    Depending on the current/voltage through the electrical wires, the micro computer will output suitable control signal to the drivers, which feeds the illuminating wires with varying current, voltage and frequency corresponding to the consumed current/voltage through the electrical wires. 
         [0031]    In a preferred embodiment, the electroluminescent wires includes a central copper wire coated with a phosphorus material coating and two tiny transmitter wires wrapped around it, and covered by a PVC coating and finally a colored vinyl coat. The driver takes the voltage from a DC power source and inverts it to, e.g. 110 volts AC. When connected to a power source and driver, the charge creates a glow in the wire, e.g. very similar to neon. 
         [0032]    Thus, the controlling arrangement controls the illuminating characteristics, e.g. intensity, color and/or pulsing (frequency) of the illuminating wires in relation to the consumed power and/or current through the electric wires. This allows obtaining a simultaneous characteristic change, shifting the pulsing in the wires to obtain visual effects such as flowing light, etc. 
         [0033]    It should be appreciated by a skilled person that the aforementioned controlling arrangement, and input and output values are given as an example and other types of controlling arrangement operating with different electrical values may occur. 
         [0034]    The invention is not limited to applications in cables and cords, especially distributor cords; the invention may likewise be applied in household appliance for providing visual indication of poser consumption of different appliances. In industrial and construction site applications, the visualization may be used for indicating overload. Especially, if many apparatuses are connected, it is possible to track a particular apparatus being overloaded or consuming high power by following the visually indicating cable. The visualization allows finding cables in limited sight situations. 
         [0035]    The invention is not limited to the shown embodiments but can be varied in a number of ways without departing from the scope of the appended claims and the arrangement and the method can be implemented in various ways depending on application, functional units, needs and requirements etc.