Abstract:
A device and a method for demounting a magnetic permeable core mounted around an electric conductor carrying electric current, the device including the core including at least two parts closed around the electric conductor, a secondary coil of electric wire wrapped around at least one part of the core, the coil having two terminals, each at one end of the coil, and a switch, electrically coupled to the two terminals, the switch being operative, when closed, to maintain a short circuit of the coil upon demand, where mounting the device on the electric conductor includes closing the two parts of the core to around the electric conductor while the switch is open, and where demounting the device from the electric conductor includes closing the switch to disengage the two parts of the core.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 62/110,637, filed Feb. 2, 2015, the disclosure of which is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The invention relates to electricity, and more particularly, to using a magnetic core around a conductor carrying a heavy duty electrical current. 
       BACKGROUND 
       [0003]    The use of a magnetic core around a conductor carrying an electric current is known in the art. It is known that a (primary) conductor carrying an electric current induces a magnetic field around the conductor, and that a core having high magnetic permeability may harvest the induced magnetic field and further transfer it to a (secondary) conductive wire wound around the core. This arrangement is used to harvest electric power from the current in the primary conductor, to sense and measure the electric current in the primary conductor, etc. The arrangement may be used also to induce an electric signal from the secondary winding into the primary winding such as in power line communication (PLC). The magnetic flux flowing in the permeable core causes magnetism which holds components of the core together. This may cause mechanical difficulties when mounting or dismounting the core in the proximity of a (primary) conductor carrying a high (heavy-duty) electric current. There is thus a need for addressing these and/or other issues associated with the prior art. 
       SUMMARY 
       [0004]    According to one aspect of the present invention there is provided a device including a core including at least two parts, the two parts being operative to close the core around an electric conductor passing there through, a coil of electric wire wrapped around at least one part of the core, the coil including two terminals, each at one end of the coil, and a switch, electrically coupled to the two terminals, the switch being operative to provide a short circuit of the coil upon demand, where mounting the device on the electric conductor includes closing the two parts of the core around the electric conductor while the switch is open, and where demounting the device from the electric conductor includes closing the switch to enable the two parts of the core to disengage from each other. 
         [0005]    According to another aspect of the present invention there is provided a device where the demounting of the core from the electric conductor is operative while the electric conductor carries electric current. 
         [0006]    According to still another aspect of the present invention there is provided a device where the core is made of a material selected from at least one of: iron, a magnetic permeable material, amorphous metals, and magnetic alloy. 
         [0007]    According to yet another aspect of the present invention there is provided a device where at least one of the core and the coil is operative to perform at least one of: measuring electric current via the coil, measuring current in the electric conductor, supplying electric power to an electric device, the electric power being drawn from the magnetic field of the electric conductor, and inducing an electronic signal into the electric conductor. 
         [0008]    Further according to another aspect of the present invention there is provided a device where the coil is a plurality of coils mounted on the core, and where the switch is electrically coupled to the terminals of at least one coil of the plurality of coils. 
         [0009]    Still further according to another aspect of the present invention there is provided a device where the coil is a plurality of coils mounted on the core, and where the switch is electrically coupled to the terminals of all the coils of the plurality of coils. 
         [0010]    Yet further according to another aspect of the present invention there is provided a device where the coil is a plurality of coils mounted on the core, and additionally including a plurality of coils, where each of the coils is electrically coupled to the terminals of a respective coil of the plurality of coils. 
         [0011]    Even further according to another aspect of the present invention there is provided a method for demounting a device mounted on an electric conductor carrying electric current, the device being operative to provide electric current from magnetic field of the electric conductor, the method providing the device including a core including at least two parts, the two parts being operative to close the core around an electric conductor passing there through, a coil of electric wire wrapped around at least one part of the core, the coil including two terminals, each at one end of the coil, and a switch, electrically coupled to the two terminals, the switch being operative to provide a short circuit of the coil upon demand. The method further including mounting the device on the electric conductor includes by closing the two parts of the core to form a ring around the electric conductor while the switch is open, and demounting the device from the electric conductor including closing the switch to enable the two parts of the core to disengage from each other. 
         [0012]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples provided herein are illustrative only and not intended to be limiting. Except to the extent necessary or inherent in the processes themselves, no particular order to steps or stages of methods and processes described in this disclosure, including the FIGURE, is intended or implied. In many cases the order of process steps may vary without changing the purpose or effect of the methods described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of several embodiments of the present invention only, and are presented in order to provide what is believed to be a useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for an understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. In the drawings: 
           [0014]      FIG. 1  is a simplified illustration of a device including a two-part core for mounting on an electric conductor, a coil, or winding around the core, and a demounting switch for disengaging the core, in accordance with one embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The present embodiments comprise a device and a method for mounting a magnetic core around a current carrying conductor, and demounting the core while electric current flows through the conductor. Particularly, the core is made of a magnetic permeable material. The principles and operation of the mounting and demounting device and method according to the various embodiments presented herein may be better understood with reference to the following drawings and accompanying description. 
         [0016]    Before explaining at least one embodiment in detail, it is to be understood that the embodiments is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings, and the embodiments may be practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
         [0017]    In this document, an element of a drawing that is not described within the scope of the drawing and is labeled with a numeral that has been described in a previous drawing has the same use and description as in the previous drawings. Similarly, an element that is identified in the text by a numeral that does not appear in the drawing described by the text, has the same use and description as in the previous drawings where it was described. 
         [0018]    The drawings in this document may not be to any scale. Different Figs. may use different scales and different scales can be used even within the same drawing, for example different scales for different views of the same object or different scales for the two adjacent objects. 
         [0019]      FIG. 1  is a simplified illustration of a power harvesting device  10  including a core  11  and a demounting switch  12 , according to one embodiment of the present invention. 
         [0020]    As shown in  FIG. 1 , a first (primary) electric conductor  13  carrying electric current is surrounded by core  11 . A secondary electric wire  14  is wound (e.g., winding  14  and/or coil  14 ) around at least a part of core  11 . The primary electric current  15  within conductor  13  induces magnetic flux within core  11 , which induces a secondary electric current in secondary wire  14 . The secondary electric current may be provided to an electric circuitry  16 . 
         [0021]    It is appreciated the purpose of core  11  is to carry magnetic flux induced by an electric current flowing in electric conductor  13 . Core  11  may therefore be made, for example, from a material having relatively high magnetic permeability such as iron. However, it is appreciated that any material or combination of materials that may be adequate and/or useful for the purpose and/or applications as described herein are contemplated. For example, amorphous metals and/or magnetic alloys such as Metglas available from Metglas Inc., 440 Allied Drive, Conway, S.C. 29526, USA. Therefore, the term ‘core’ in this document refers to any such device, made from an adequate material, and configured to be closed around an electric conductor configure to carry electric current. 
         [0022]    Electric circuitry  16  may configured to operate on the electric power harvested from the primary electric current  15  via secondary winding  14 . Alternatively, or additionally, electric circuitry  16  may be configured to measure the primary electric current  15  via secondary winding  14 . Alternatively, or additionally, electric circuitry  16  may be configured to induce an electronic communication signal (e.g., PLC) via secondary winding  14  into conductor  13 . Similar other applications are also contemplated. 
         [0023]    It is appreciated that there may be any number of winding  14 , for example, for different purposes as explained above. Such plurality of winding  14  may be placed in various places over core  11   
         [0024]    As shown in  FIG. 1 , core  11  may have two or more parts to enable mounting core  11  on conductor  13 , for example, after conductor  13  is installed and connected at both ends (not shown in  FIG. 1 ). As shown in  FIG. 1 , when mounted on conductor  13 , core  11  is closed in the shape of a ring around conductor  13 . It is appreciated that core  11  may have any shape enabling conductor  13  to pass there through. The core  11   FIG. 1  includes a first part  17  and a second part  18  connected by an axle  19 . 
         [0025]    It is appreciated that instead of axle  19  is not essential, and that the parts of core  11  may be positioned together around the electric conductor without using an axle. Alternatively, for example, each part of core  11  may be contained in a container and the axle may be part of the containers rather than the core. For example, the core  11  may have more than two parts. For example, the core  11  may have two axles, each at each end of part  18 , and two rotating parts such as part  17 . It is appreciated that any arrangement for mounting and/or closing a core around an electric conductor is contemplated. 
         [0026]    When the core  11  is mounted and closed around conductor  13  carrying electric current  15  the core  11  magnetized and the two parts  17  and  18  are held together firmly at the opening  20 . This magnetic force may prevent demounting core  11  from conductor  13  as long as conductor  13  carries high electric current  15 . It is appreciated that when mounting core  11  on conductor  13 , and/or dismounting core  11  from conductor  13 , opening  20  should be wide enough to allow the conductor  13  to pass there through. It is appreciated that when core  11  is closed around conductor  13 , opening  20  is firmly and/or tightly closed to allow magnetic flux to flow there through. 
         [0027]    To enable demounting core  11  from conductor  13  while carrying high electric current  15  switch  12  may be closed to provide short-circuit over winding  14  and thus reduce the magnetism of core  11  and enable the opening of core  11 . It is appreciated that opening of core  11  may involve parting and/or detaching and/or separating and/or disengaging the two or more parts of core  11 . 
         [0028]    As shown in  FIG. 1 , switch  12  provides short-circuit of winding  14  which is also used for an application such as power harvesting, current measurement, and/or PLC. However, it is appreciated that alternatively or additionally, switch  12  provides short-circuit of an additional winding. In such embodiment, for example, a first winding is connected to switch  12  to enable opening of the core  11  for demounting the device from the conductor  13  while the electric current is flowing through the conductor  13 , and a different, second, winding is connected to electric circuitry  16 , for example, for measuring electric current flowing through conductor  13 , and/or for harvesting electric power electric current flowing through conductor  13 , and/or for inducing electric signal into conductor  13 . As described above, any number of winding is contemplated. 
         [0029]    Switch  12  may be operated manually, directly, by pressing or turning the switch. Alternatively or additionally, as shown in  FIG. 1 , switch  12  may be operated indirectly using an actuator  21  (e.g., an electromechanical actuator such as a solenoid actuator) connected to a manually operated switch or a controller  22  remotely operated, for example, using an RF signal. 
         [0030]    It is appreciated that a device such as a spring or an electromechanical actuator may be added to device  10 , such as about the axle  19 , to assist in closing and/or opening the two parts of the core  11 . It is appreciated that a controller such as controller  22  may be operative to synchronize the operation of switch  12  (such as by controlling the operation of actuator  21 , with the operation of the electromechanical actuator operative to open (and/or close) the two parts of core  11 . 
         [0031]    It is appreciated that alternatively, or additionally, if a plurality of windings, such as winding  14 , are provided (as described above) a corresponding plurality of switches, such as switch  12 , may be provided, where each such switch may provide a short circuit of a corresponding winding. In an embodiment contemplated herein, where a plurality of windings (such as winding  14 ) is provided on core  11 , each and every one of the winding includes a switch (such as switch  12 ) configured to provide a short circuit of the corresponding winding. 
         [0032]    It is appreciated that the operation of these switches may be coordinated. For example, controller  22  may be operative to synchronize the operation of the plurality of switches  12  for example by controlling the operation of a respective plurality of actuators  21 , as well as controlling the operation of an actuator closing and/or opening core  11 . It is appreciated that instead of a plurality of switches it is possible to use a single switching device including a plurality of contactors. 
         [0033]    It is appreciated that certain features of the invention, which are, described in the context of different embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination. 
         [0034]    Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.