The present invention generally relates to an electricity meter, The present invention more particularly relates to a clamp-on type electricity meter configured to measure current and/or voltage.

Prior art

Electricity sensors are well known and widely used to carry out electricity measurements. Electricity meters are the most accurate types, however, they are not provided in simple clamp-on versions. Accordingly, installation of such electricity meters requires that cables are cut to get access to a number of required measurement points. E.g. from US 4,706,017 A, current sensors are known. The sensor comprises a substantially annular coil assembly having a pair of output terminals and having closed-loop flux concentrating means. The flux concentrating means is adapted to be positioned in juxtaposition with the current-carrying conductor and to extend as a core through the coil assembly. The coil assembly is substantially planar in form and is mounted on a substrate.

Clamp-on electricity sensors are also known. The typical clamp-on type electricity sensor configured to measure current comprises a number of coils (i .e. current transformers) each coiled around a corresponding metal core. Each coil needs to be electrically connected to a printed circuit board (PCB), As illustrated in Fig. 8 A in a first step, a core is provided. In the next step (as shown in Fig. SB), the coil is coiled around a core and in a third step (shown in Fig. 8C), the coil coiled around the core is electrically connected to a PCB. This procedure is difficult and expensive.

Such clamp-on sensor is e.g. known from US 9,372,207 Bl . Said patent disclose a power measurement transducer having a split core transformer positioned along an axial extent of an eccentric channel for enclosing a conductor. The eccentric channel has a first piercing pin in a first piercing pin extent, and a second piercing pin in a second piercing pin extent. The first and second channel extents being located on opposite sides of the split core transformer and on the conductor axis such that the conductor is an insulation piercing distance from the piercing pin. Thus and as described above, there is a need for an improved and easier producible clamp-on type electricity sensor configured to measure current.

It is an object of the present invention to provide a clamp-on type electricity sensor configured to measure current, which is easier and less expensive to produce than the prior art clamp-on type electricity sensor configured to measure current.

Summary of the invention

The object of the present invention can be achieved by an electricity meter as defined in claim 1. Preferred embodiments are defined in the dependent subclaims, explained in the following description and illustrated in the accompanying drawings.

The electricity meter according to the invention is a clamp-on type electricity meter configured to measure current and comprising at least one core assembly and a coil coiled around a structure of the corresponding core assembly, wherein the coil is electrically connected to a printed circuit board (PCB), wherein the core assembly is a split core comprising a first portion and a second portion attached to each other in a joint portion and the coil is an integrated part of the PCB, and wherein the electricity meter comprises two, three, four or more core assemblies each extending through a corresponding coil electrically connected to the PCB, where the core assemblies are arranged in a predefined configuration, wherein the current measure- ments made by one of the core assemblies is used when carrying out a current measurement made by one of the other core assemblies,

Hereby, it is possible to provide a clamp-on type electricity meter configured to measure current, which is easier and less expensive to produce than the prior art clamp-on type electricity meter configured to measure current. Furthermore, it is possible to compensate for the current measurements made by the other core assemblies.

The electricity meter according to the invention is a clamp-on type electricity meter configured to measure current. In a preferred embodiment according to the invention, the electricity meter comprises a voltage measuring unit configured to measure voltage.

The electricity meter comprises at least one core assembly and a coil coiled around a structure of the corresponding core assembly. The electricity meter may comprise one, two, three, four, five or more core assemblies depending on the application, in which the electricity meter is intended to be used. The coil is electrically connected to a PCB. The PCB may be of any suitable size, geometry and type, it may be an advantage that the PCB is basically rigid plate-shaped.

The core assembly is a split core comprising a first portion and a second portion attached to each other in a joint portion, By having a core assembly which is a split core comprising a first portion and a second portion attached to each other in a joint portion, it is possible to assemble the electricity meter in a simple manner, in which either the first portion and a second portion is inserted through a coil and wherein the first portion and the second portion are attached to each other afterwards,

The joint portion may be of any suitable type. It is, however, preferred, that the joint portion is simple and easy to produce and assemble, It may be an advantage that the PCB is configured to measure voltage. By having a voltage measuring unit integrated in the PCB, it is possible to provide a compact electricity meter.

It is advantageous that the coil is an integrated part of the PCB.

Hereby, the cost and production time of the electricity meter can be minimised. It may be an advantage that the coil has a flat shape extending along the plane of the PCB, It may be beneficial that a gap is provided between the first portion and the second portion. Hereby, it is possible to reduce or even eliminate externally induced signals. The gap may be air-filled. Alternatively, a non-conducting material such as plastic may be filled into the gap.

It may be advantageous that the first portion and the second portion are joined by a finger joint as a finger joint is easy to produce and assemble. It may be beneficial that a temperature sensor is provided in the core assembly or close thereto and that the electricity meter comprises a compensating unit configured to compensate the current measurement for the temperature on the basis on the detected temperature.

Hereby, it is possible to improve the meter output by performing a temperature adjustment based on the detected temperature,

It may be advantageous that the core assemblies extend parallel to each other and are arranged in a zigzag configuration.

Hereby, it is possible to arrange one or more cables in the space between adjacent core assemblies.

It may be an advantage that the core assemblies are interspaced and that the space between adjacent core assemblies is sufficient to insert a cable between two adjacent core assemblies. Hereby, the meter is easier to mount on the cable.

It may be advantageous that the electricity meter comprises a spike (or knife, or needle) arranged to be inserted into a conductor of the cable to be measured by means of the electricity meter and hereby establish an electrical connection to the conductor.

Hereby, it is possible to establish an electric connection in an easy and safe manner. The spike may preferably be made of a metal, such as copper. It is possible to apply other electrically conducting material.

It may be advantageous that the electricity meter comprises a cable relieve configured to fix the conductors in a predefined manner. Hereby, it is possible to, at the same time, relieve the cable and fix the conductors in a predefined manner. It may be an advantage that the cable relieve is provided with the spike and is configured to be opened and closed, wherein the cable relieve is configured to bring the spike into electrical connection with a connector when the cable relieve is being closed.

Hereby, it is possible to eliminate the risk of getting an electric shock when inserting the spike into electric contact with a conductor,

It may be an advantage to use a spike made in a metal, preferably copper, It is possible to at least partly cover the spike with a layer of anti-oxidant compound in order to prevent oxidation of the spike 36 and hereby enhance the electrical conductivity of the spike. The compound may contain grade zinc and/or metallic zinc.

It may be advantageous that the electricity meter comprises an energy harvester configured to harvest electrical energy to energise the electricity meter. Hereby, the need for an energy source (e.g. a battery) may be reduced or even eliminated.

Description of the Drawings

The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:

Fig. 1A shows a schematic, perspective view of a meter assembly according to the invention;

Fig. IB shows a schematic end view of the meter assembly shown in Fig. 1A;

Fig. 2A shows a schematic top view of a meter assembly according to the invention;

Fig. 2B shows a schematic side view of the meter assembly shown in Fig. 2A;

Fig. 2C shows a cross-sectional view of the meter assembly shown in Fig. 2A and Fig. 2B;

Fig. 3A shows a perspective view of a first portion of a core assembly according to a meter assembly of the invention;

Fig. 3B shows a side view of the first core portion shown in Fig.

3A;

Fig. 3C shows a front view of the first core portion shown in Fig.

3A and Fig. 3B;

Fig. 3D shows a close-up view of the first core portion shown in

Fig. 3C;

Fig. 3E shows an end view of the first core portion shown in Fig.

Fig. 4A shows an end view of a first printed circuit board according to a meter assembly of the invention;

Fig. 4B shows a top view of the first printed circuit board shown in

Fig. 4A;

Fig, 4C shows a perspective view of the first printed circuit board shown in Fig. 4A and in Fig. 4B;

Fig. 5A shows a front view of a second portion of a core according to a meter assembly of the invention;

Fig. 5B shows a side view of the second core portion shown in Fig.

5A;

Fig. 5C shows a perspective view of the second core portion shown in Fig. 5A and in Fig. 5B;

Fig. 5D shows an end view of the second core portion shown in

Fig. 5A, Fig. 5B and in Fig. 5C;

Fig. 6A shows a perspective, front view of a cable relieve according to a meter assembly of the invention; Fig. 6B shows a perspective, side view of the cable relieve shown in Fig. 6A;

Fig. 7A shows a front view of a core assembly according to a meter assembly of the invention;

Fig . 7B shows a side view of the core assembly shown in Fig, 7A; Fig , 7C shows a perspective view of the core assembly shown in

Fig. 7A and Fig . 7B;

5 Fig . 7D shows an end view of the core assembly shown in Fig . 7 A,

Fig. 7B and Fig . 7C;

Fig . 8A shows a schematic view of a coil-core assembly of prior art clamp-on type electricity meter configured to measure current being assembled;

1 0 Fig . SB shows a schematic view of the coil-core assembly shown in Fig . 8A, wherein a coil is being coiled around the core assembly;

Fig . 8C shows a schematic view of the coil-core assembly shown in Fig . 8B, wherein a coil has been electrically connected 1 5 to a printed circuit board;

Fig . 9A shows an end view of an electricity meter according to the invention comprising a cable relieve according to the invention;

Fig . 9B shows a cross-sectional view of the electricity meter 20 shown in Fig. 9A;

Fig . 9C shows a top view of the electricity meter shown in Fig. 9A and Fig . 9B;

Fig . 9D shows a cross-sectional view of the electricity meter shown in Fig. 9C;

25 Fig . 10A shows a cross-sectional view of the electricity meter shown in Fig, IOC;

Fig , 10B shows a close-up view of the electricity meter shown in

Fig. 10A;

Fig . 10 C shows a schematic view of the electricity meter shown in 30 Fig. 10A;

Fig . iOD shows a top view of the electricity meter shown in Fig.

IOC; Fig, 11A shows a perspective top view of a core assembly according to the invention;

Fig, 11B shows a front view of the core assembly shown in Fig, 11A and

Fig, I IC shows an exploded view of the first core portion and the second core portion of a core assembly of the invention.

Detailed description of the invention

Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, a meter assembly 2 of the present invention is illustrated in Fig. 1A.

Fig. 1A illustrates a schematic, perspective view of a meter assembly 2 according to the invention. The meter assembly 2 constitutes a part of a clamp-on type electricity meter according to the invention configured to measure current. The meter assembly 2 comprises a printed circuit board (PCB) 4 provided with a plurality of openings 16 and a connection portion 14 configured to be inserted into a corresponding electric receiving portion. The connection portion 14 protrudes from the remaining part of the PCB 4 and comprises a plurality of parallel connectors adapted to be brought into electric connection with corresponding electrically conducting structures.

The PCB 4 is a plane plate-shaped structure extending along a longitudinal axis Y and a lateral axis X. The PCB 4 has a transverse axis Z extending perpendicular to the longitudinal axis Y and the lateral axis X.

The meter assembly 2 comprises a first core assembly 8, a second core assembly 8', a third core assembly 8" and a fourth core assembly 8'". Each core assembly 8, 8', 8", 8'" extends through a first opening 16 and a second opening 16' surrounded by a coil 6, 6' embedded in the PCB 4. The longitudinal axis of each of the core assemblies 8, 8', 8", 8"' extend along the transverse axis Z of the PCB 4. This means that the core assemblies 8, 8', 8", 8"' extend perpendicular to the PCB 4. It can be seen that each core assembly 8 _? 8', 8", 8'" comprises a firs portion and a second portion and that a gap 18 is provided between the first portion and the second portion , The core assemblies 8, 8% 8", 8"' extend parallel to each other and are arranged in a zigzag configuration . Fig , I B illustrates a schematic end view of the meter assembly 2 shown in Fig , 1A, it can be seen that the meter assembly 2 comprises a first core assembly 8 extending through openings provided in the bottom region of the PCB 4. The meter assembly 2 comprises a second core assembly 8' arranged above the first core assembly 8 and extending through openings provided in the PCB 4 above the first core assembly 8. The meter assembly 2, furthermore, comprises a third core assembly 8" arranged above the second core assembly 8' and extending through openings provided in the PCB 4 above the second core assembly 8'. Moreover, the meter assembly 2 comprises a fourth core assembly 8"' arranged above the third core assembly 8" and extending through openings provided in the top portion of the PCB 4 above the third core assembly 8", The gaps 18 provided between the first portion and the second portion of the second and fourth core assemblies 8', 8" are indicated , It can be seen that the core assemblies 8, 8', 8", 8"' extend parallel to the transverse axis Z of the PCB 4 and perpendicular to the lateral axis X of the PCB 4. The major portion of the first core assembly 8 and the second core assembly 8' protrude to the left from the PCB 4, whereas the major portion of the third core assembly 8" and the fourth core assembly 8 ^f " protrude to the right from the PCB 4. The core assemblies 8, 8', 8", 8'" are formed as lam inated constructions each comprising a plurality of laminations provided to increase the efficiency of the core assembly 8, 8% 8", 8"'. Fig. 2A illustrates a schematic top view of a meter assembly 2 according to the invention. The meter assembly 2 is a part of a clamp- on type electricity meter according to the invention configured to measure current. The meter assembly 2 is provided with a PCB 4 having a plurality of openings 16, 16' and a connection portion 14 protruding from the remaining portion of the PCB 4. The connection portion 14 is configured to be inserted into a corresponding electric receiving portion. The connection portion 14 is equipped with a plurality of parallel connectors adapted to be electrically connected to corresponding electrically conducting structures.

It can be seen that the first core assembly 8 extends through a first opening 16 and through a second opening 16' surrounded by a coil 6 integrated in the PCB 4. Likewise, the second core assembly 8' extends through a first opening 16 and through a second opening 16' surrounded by a coil 6' integrated in the PCB 4. Both the third and the fourth core assemblies 8", 8" extend through a first opening and through a second opening surrounded by a coil integrated in the PCB 4, however, these coils are not visible from this side of the PCB 4. The longitudinal axis Y and the lateral axis X of the PCB 4 are shown in Fig. 2A.

The core assemblies 8, 8', 8", 8"' extend parallel to each other and are arranged in a zigzag configuration. This configuration makes it easier to arrange the core assemblies 8, 8', 8", 8"' between the conductors on the cables to be monitored. Accordingly, the electricity meter according to the invention can easily be mounted on a cable. Since the configuration of the core assemblies 8, 8', 8", 8"' is predefined, it is possible to adjust for interactions (from the core assemblies 8, 8', 8", 8"'). Furthermore, it is possible to adjust for externally induced signals, e.g. by using the assumption that the sum of ail currents must be zero,

The electncity meter according to the invention can be used to alert a user if a too high current is detected by the electricity meter. Moreover, the electricity meter according to the invention can be applied to detect the direction of the current.

Fig. 2B illustrates a schematic side view of the meter assembly 2 shown in Fig, 2A. It can be seen that the core assemblies 8, 8', 8", 8'" extend through openings in the PCB 4. The connection portion 14 protruding from the remaining portion of the PCB 4 is indicated in Fig. 2B. The fourth core assembly 8'" comprises a first portion 10 and a second portion 12 attached thereto. Each of the other core assemblies 8, 8% 8" also comprises a first portion and a second portion attached thereto. Each first portion 10 can be provided with a number of teeth 11 distributed at the distal portion of the first portion 10. The core assemblies 8, 8', 8", 8'" extend along the transverse axis Z of the PCB 4 and perpendicular to the longitudinal axis Y of the PCB 4. A section line A is indicated.

Fig. 2C illustrates a cross-sectional view of the meter assembly shown in Fig. 2A and Fig. 2B. The section line A is indicated in Fig. 2B. Each core assembly 8, 8', 8", 8"' comprises a laminated structure (comprising 10 layers). The number of layers may be increased or reduced if desired. Each core assembly 8, 8', 8", 8"' extends through openings 16 in the PCB 4. The major portion of the first and second core assembly 8, 8' protrude from one side of the PCB 4, whereas the major portion of the third and fourth core assembly 8", 8'" protrude from the opposite side of the PCB 4.

Fig. 3A illustrates a perspective view of a first portion 10 of a core assembly according to a meter assembly of the invention. The first portion 10 is a basically L-shaped laminated construction comprising a plurality of laminations provided to increase the efficiency of the core assembly. The L-shaped first portion 10 comprises a first tooth 20 and a second tooth 20' arranged parallel to the first tooth 20. The teeth 20, 20' are provided in the first end portion of the first portion 10 and protrude from the outer periphery of the first portion 10. The two teeth 20, 20' each comprises two laminations spaced from each other and have a triangular cross section. The function of the teeth 20, 20' is to retain the core in the encapsulation.

In the other end portion of the first portion 10, a first protruding portion 22 and a second protruding portion 22' separated by a receiving portion 24' are provided.

Fig. 3B illustrates a side view of the first core portion 10 shown in Fig. 3A. it can be seen that the first core portion 10 comprises 10 laminations and that the teeth 20, 20' are provided near the top portion of the first core portion 10.

Fig. 3C illustrates a front view of the first core portion 10 shown in Fig. 3A and Fig. 3B. The first tooth 20 and the protruding portion 22 are indicated in Fig. 3C.

Fig. 3D illustrates a close-up view of the first core portion 10 shown in Fig, 3C. It can be seen that the tooth 20 has a triangular cross section, wherein the triangle is equal-sided ad protrudes from the remaining portion of the first core portion 10.

Fig. 3E illustrates an end view of the first core portion 10 shown in Fig. 3A. The first core portion 10 comprises a first protruding portion 22 arranged sandwiched between a first receiving portion 24 (indicated with a dotted line) and a second receiving portion 24' (indicated with a dotted line), The first core portion 10 moreover comprises a second protruding portion 22' sandwiched between the second receiving portion 24' and a third receiving portion 24", The protruding portions 22, 22' each comprise two laminations.

The first core portion 10 comprises a first tooth 20, a second tooth 20' and an air gap interspaced there between.

Fig. 4A illustrates a schematic end view of a first PCB 4 according to a meter assembly of the invention. Fig. 4B illustrates a top view of the first PCB 4 shown in Fig. 4A, and Fig. 4C illustrates a perspective view of the first PCB 4 shown in Fig. 4A and in Fig. 4B.

In Fig. 4A, the structures provided in the PCB 4 are indicated by dotted lines. It can be seen that the PCB 4 has a plane plate-shaped structure with a uniform cross section, except from the connection portion 14. As illustrated in Fig. 4B, the PCB 4 comprises a first area I provided with a first opening 16 and a second opening 16' configured to receive the first portion and the second portion of a corresponding core assembly. Likewise, the PCB 4 comprises a second area II provided with a first opening and a second opening adapted to receive the first portion and the second portion of a corresponding core assembly. The PCB 4, furthermore, comprises a third area III provided with a first opening and a second opening adapted to receive the first portion and the second portion of a corresponding core assembly and a fourth area IV provided with a first opening 16 and a second opening 16' configured to receive the first portion and the second portion of a corresponding core assembly. The core assemblies 8, 8', 8", 8"' extend parallel to each other and are arranged in a zigzag configuration.

Fig. 5A illustrates a front view of a second portion 12 of a core according to a meter assembly of the invention. Fig. 5B illustrates a side view of the second core portion 12 shown in Fig. 5A. Fig. 5C illustrates a perspective view of the second core portion 12 shown in Fig. 5A and in Fig. 5B, whereas Fig. 5D illustrates an end view of the second core portion 12 shown in Fig. 5A, Fig, 5B and in Fig. 5C.

The second portion 12 is L-shaped ad configured to be attached to the first portion shown in Fig. 3A. The second portion 12 comprises a plurality of laminations provided to increase the efficiency of the core assembly.

In Fig. 5B, it can be seen that the second portion 12 comprises a first protruding portion 26, a second protruding portion 26' and a third protruding portion 26" interspaced by air-filled receiving portions 28, 28 ^f . The protruding portions 26, 26', 26" are configured to be received by corresponding receiving members of the first portion (see 22, 22' on Fig. 3A and Fig. 3E). Likewise, the receiving portions 28, 28' are configured to receive corresponding protruding members of the first portion (see 24, 24', 24" on Fig. 3E). In Fig. 5C, it can be seen that the protruding portions 26, 26', 26" extend in extension of the remaining lamination of the longest portion of the second portion 12.

Fig. 6A illustrates a perspective, front view of a cable relieve 40 according to a meter assembly of the invention. Fig. 6B illustrates a perspective side view of the cable relieve 40 shown in Fig. 6A. It can be seen that the cable relieve 40 comprises a base portion 50 and a closing portion 52 rotatably attached thereto. The base portion 50 and the closing portion 52 are basically shaped as semi-cylindrical structures and rotatably attached to teach other by a joint 48. The base portion 50 is provided with a number of locking structures 38', and the closing portion 52 is provided with corresponding locking structures 38 arranged to lockingiy engage with the locking structures 38' of the base portion 50 in order to attach the free end of the base portion 50 to the free end of the closing portion 52. The locking structure 52 is provided with an electrically conducting spike 36 configured to establish an electrical connection to one of the conductors 32, 32', 32" of the cable 30 relived by the cable relieve 40. When the cable relieve 40 is being closed, the locking structures 38' of the base portion 50 and the locking structures 38 of the closing portion 52 wi ll approach each other and the spike 36 wi ll penetrate the outside insulation 34 of the cable 30 and the underlying structure. Eventually, when the cable relieve 40 is closed, the locking structures 38' of the base portion 50 will lockingiy engage with the locking structures 38 of the closing portion 52, and the spike 36 will have established an electrical connection to one of the conductors 32, 32', 32" of the cable 30. Hereby, the spike 36 can be used to measure a voltage (a potential difference between the conductor connected to the spike 36 and a reference point). The base portion 50 and the closing portion 52 of the cable relieve 40 are preferably made in electrically non- conducting materials such as plastic.

The cable relieve 40 is intended to relieve cables 30 and at the same time ensure that the cable relieve 40 is orientated correctly with respect to the cable 30. Since the spike 36 is brought into electrical connection with the connector 32, 32', 32", when the cable relieve 40 is closed, the risk of getting an electric shock is eliminated. It may be an advantage to use a spike made of a metal, preferably copper, it is possible to at least partly cover the spike 36 with a layer of anti-oxidant compound in order to prevent oxidation of the spike 36 and hereby enhance the electrical conductivity of the spike 36. The compound may contain grade zinc and/or metallic zinc.

Fig. 7A illustrates a front view of a core assembly 8 according to a meter assembly of the invention. Fig. 7B illustrates a side view of the core assembly 8 shown in Fig. 7A. Fig. 7C illustrates a perspective view of the core assembly 8 shown in Fig. 7A and Fig. 7B _f whereas Fig. 7D illustrates an end view of the core assembly 8 shown in Fig. 7A, Fig. 7B and Fig. 7C.

The core assembly 8 comprises a first L-shaped portion 10 attached to a second L-shaped portion 12. An air-filled gap 18 is provided between the first portion 10 and the second portion 12; however, it is possible to insert an electrical insert member made of an insulating material into the gap 18. The core assembly 8 constitutes a basically rectangular core construction, when the first portion 10 and the second portion 12 are attached to each other. The first portion 10 and the second portion 12 are mechanically attached to each other by inserting the protruding portion of the first portion 10 (see Fig. 3A and Fig. 3E) into the corresponding receiving portions of the second portion 12 (see Fig. 5B and Fig. 5C) and inserting the protruding portion of the second portion 12 (see Fig. 5B and Fig. 5C) into the corresponding receiving portions of the first portion 10 (see Fig. 3A and Fig. 3E). The first portion 10 and the second portion 12 are joint in the joint portion 42 indicated.

Fig. 8A illustrates a schematic view of a coil-core assembly 8 of a prior art clamp-on type electricity meter configured to measure current being assembled. The coil-core assembly 8 comprises a core assembly 8 arranged above a PCB 4 provided with two bores 44. The core assembly 8 has a basically square configuration. Fig. 8B illustrates a schematic view of the coil-core assembly shown in Fig. 8A, wherein a coil 8 is being coiled around the core assembly 8. The coiling process is time consuming and difficult, since the coil 6 is required to be coiled around the core assembly 8 by inserting the coil wire through the opening in the core assembly 8 and around the lower portion of the core assembly a repetitive number of times. When the coiling process is accomplished, the free ends of the coil wire need to be electrically connected to the PCB 4 as shown in Fig. 8B. This mounting process is difficult in production, because the core must be supported during the soldering process.

Fig. 8C illustrates a schematic view of the core assembly 8 shown in Fig. 8B, wherein a coil 6 has been electrically connected to the PCB 4. The free ends of the coil wires have been inserted into the bores in the PCB 4 (see 44 in Fig. SB) and the solder 46 has been provided to fix the coil 6 to the PCB 4.

Fig. 9A illustrates an end view of an electricity meter according to the invention comprising a cable relieve 40 according to the invention. The cable relieve 40 is integrated in a housing having a base portion 50 and a closing portion 52 detachabiy attached thereto. The housing is provided with openings in the front end and in the rear end. Each opening is provided with an aperture 60 surrounded by a clamping structure 54 adapted to press against and hereby clamp a cable into a secured, fixed position. The clamping structure 54 may be provided as resilient structures made of rubber or another suitable material. The clamping structure 54 shown in Fig. 9A has a ring-shaped geometry and is centrally arranged with respect to the aperture 60. A connection portion 14 of a PCB (provided in the housing and thus not visible in Fig, 9A) protrudes from the joint structure provided between the base portion 50 and the closing portion 52. A locking hook 56 is provided on each side of the connection portion 14. The locking hooks 56 are configured to be used for attaching a transmitter unit (not shown) to the housing of the cable relieve 40.

Fig , 9B illustrates a cross-sectional view of the electricity meter shown in Fig, 9A. It can be seen that the base portion 50 and a closing portion 52 are attached to each other and that a cable 30 extends through the housing of the cable relieve 40 of the electricity meter. The cross section is made along the line C-C indicated in Fig. 9A. The cable 30 comprises a first conductor 32 and a second conductor 32' arranged in different positions in the housing . A first locking plate 62 is provided in the housing to press the first conductor 32 towards the central portion of the housing, hereby establishing electrical contact with a spike (see Fig. 9D and Fig. 10B) . A spring member 64 is provided in the housing and arranged and configured to press the conductor 32 outwards (in the opposite direction than the locking plate 62) . The locking plate 62 is attached by means of screws (see Fig . 10D). Fig . 9C illustrates a top view of the electricity meter shown in Fig . 9A and Fig . 9B, The longitudinal section plane D-D as well as an additional plane E-E extending parallel thereto are indicated in Fig , 9C. The closing porting 52 of the housing is visible in Fig. 9C. It can be seen that the connection portion 14 (of the PCB provided in the housing) protrudes from the left side of the housing .

Fig . 9D illustrates a cross-sectional view (along the section plane E-E) of the electricity meter shown in Fig. 9C. The electricity meter is built in a cable relieve 40 arranged in a housing. A first conductor 32 and a second conductor 32 ^f extend through the housing along two different patches.

A PCB 4 is arranged centrally in the housing and extends along the longitudinal axis of the housing. Four core assemblies 8, 8', 8", 8"' are integrated in the PCB 4. The first conductor 32 extends along the first and second core assemblies 8, 8', whereas the second conductor 32' extends along the third and fourth core assemblies 8", 8"'.

Fig. 9E illustrates a cross-sectional view (along the section plane D-D) of the electricity meter shown in Fig. 9C. The electricity meter is built in a cable relieve 40 arranged in a housing. It can be seen that a first conductor 32 and a second conductor 32' are extending through the housing along two different patches. The first conductor 32 extends along a first and a second core assembly 8, 8', whereas the second conductor 32' extends along a third and a fourth assembly 8", 8"'. The first conductor 32 and the second conductor 32' have been stripped from the main reinforcement of the cable 30 entering the housing in a first end and leaving the housing in the opposite end of the housing. The cable relieve 40 comprises a clamping structure 54 provided in each end of the housing. The clamping structures 54 are arranged and configured to clamp against the cable 30 and hereby secure it to the housing. Hereby, the clamping structure 54 relieves the cable 30.

Fig, 9F illustrates a perspective top view of the electricity meter shown in Fig. 9C. The electricity meter is integrated in a cable relieve 40 clamped on a cable 30. The cable relieve 40 comprises a housing having a base portion 50 and a closing portion 52 detachably attached thereto by means of locking members 58 of the base portion 50 lockingiy received by corresponding openings provided in the closing portion 52, Hereby, it is possible to assemble the housing and attach the closing portion 52 to the base portion 50 of the housing in a fast and easy manner. A connection portion 14 of a PCB, provided in the housing, protrudes from the joint structure provided between the base portion 50 and the closing portion 52. One locking hook 56 is provided over and under the connection portion 14. The locking hooks 56 are adapted to be used for attaching a detachably attached transmitter unit (not shown) to the housing of the cable relieve 40. The cable relieve 40 is provided with a clamping structure 54 provided in each end of the housing. The clamping structures 54 are arranged and configured to clamp against the cable 30 in order to fixedly secure the cable 30 to the housing. Accordingly, the clamping structure 54 is configured to relieve the cable 30.

Fig. 10A illustrates a cross-sectional view (along the section plane A-A) of the electricity meter shown in Fig. IOC. Fig. 10B illustrates a close- up view of the electricity meter shown in Fig. lOA. The electricity meter is built in a cable relieve arranged in a housing, through which a first conductor 32 extends. The conductor 32 is surrounded by insulation 66. A locking plate 62 is arranged to press the conductor 32 towards the central portion of the housing, hereby establishing electrical contact to a spike 36 extending basically perpendicular to the conductor 32. The conductor 32 is arranged to extend along the side portion of a core assembly 8 of the electricity meter. A spring member 64 is arranged to press the conductor 32 outwards (in the opposite direction than the locking plate 62). The spring member 64 is formed as a bendable structure that wil l press against the connector 32 and its surrounding insulation 66. The larger diameter the connector 32 and its surrounding insulation 66 have the more the spring member 64 will be deformed (bent). Fig, 10 C illustrates a schematic view of the electricity meter shown in Fig. 10A. A PCB is centrally arranged and comprises a connection portion 14 protruding from the remaining part of the electricity meter. A first and a second core assembly 8, 8' are provided as integrated components of the PCB.

Fig. 10D iiiustrates a top view of the electricity meter shown in Fig. IOC. The electricity meter comprises a centrally arranged PCB having a connection portion 14 protruding from the remaining part of the electricity meter. A first and a second core assembly 8, 8' are integrated components of the PCB. A conductor 32 extends through the second core assembly 8'. The conductor 32 is kept in the correct position by means of a locking plate 62 attached to the underlying structure by means of a screw 68. The electricity meter comprises an additional locking plate 62 attached to the underlying structure by means of a screw 68.

Fig, 11A illustrates a perspective top view of a core assembly 8 according to the invention. Fig. 11B illustrates a front view of the core assembly 8 shown in Fig. 11A, and Fig. 11C illustrates an exploded view of the first core portion 10 and the second core portion 12.

The core assembly 8 comprises a first core portion 10 provided with a plurality of through-going bore 70 and a second core portion 12 also provided with a plurality of through-going bore 70 configured to receive pins for connecting the sheets of the core portions 10, 12, in Fig, 11A and Fig, 11B, the first core portion 10 and the second core portion 12 are joined in a joint portion 42. In Fig. I IC, it can be seen that the first core portion 10 comprises a rounded end portion 74 configured to be received by a corresponding groove structure 72 provided in the first core assembly 10. Hereby, the joint portion 42 makes it possible for the first core portion 10 and the second core portion 12 to move relative to each other when assembled, where a gap 18 is provided between the first core portion 10 and the second core portion 12.

List of reference numerals

2 Meter assemble

4 Printed circuit board

6, 6' Coil

Q Q ' Q "

O , O , O Core assembly

10 First core portion

12 Second core portion

14 Connection portion

16, 16' Opening

18 Gap

20, 20' Tooth

22, 22' Protruding portion

24, 24', 24" Receiving portion

26, 26', 26" Protruding portion

28, 28' Receiving portion

30 Cci bis

Conductor

34 Outside insulation

36 Spike

38, 38' Locking structure

40 Cable relieve

42 Joint portion

44 Bore

46 Solder

48 Joint

50 Base portion

52 Closing portion

54 Clamping structure

56 Locking hook

58 Locking member 60 Aperture

62 Locking plate 64 Spring member 66 Insulation 68 Screw

70 Bore

72 Groove structure

End portion

I, II, II, IV Area

X, Y, Z Axis