Magnetic Field Detector Module

Abstract

A magnetic field detector module (1) including a pair of magnetic field concentrators (5), an air gap (7) formed between the pair of magnetic field concentrators, a magnetic field sensing cell (2) mounted within the air gap, a plurality of terminals (3) for interconnecting the magnetic field sensing cell to an external circuit, and an insulating housing (4) in which the magnetic field concentrators, the magnetic field sensing cell, and the terminals are assembled. The magnetic field detector module further includes a circuit board (8) on which the magnetic field sensing cell is mounted and a portion of the circuit board is inserted into the air gap, each terminal (3) having a substantially flat shape cut from a sheet of metal disposed substantially perpendicular to the circuit board and including an inner board connection portion having a pair of opposing contacts (9) separated by a slot (11), each contact engaging a respective side of the circuit board.

Description

[Technical Field]

[0001] The present invention relates to a magnetic field detector module, particularly for use in current sensing applications. [Background technology]

[0002] A magnetic field detector module integrated into a current converter is described in patent application publication WO2020 / 157019. In the aforementioned publication, the magnetic field detector module includes a magnetic field sensing cell in the form of an ASIC positioned in the air gap between magnetic field concentrators overmolded in a dielectric and presenting contacts mounted on the circuit board of the current converter. A U-shaped magnetic core surrounding a central passage through which a primary conductor is inserted is connected to the magnetic field detector module. However, such a magnetic field detector module can be integrated into a system for measuring magnetic fields with or without the magnetic core.

[0003] Depending on requirements such as measurement accuracy, measurement range, durability, and environmental conditions in which the magnetic field detector module may be implemented, different magnetic sensing cells and signal processing features of the magnetic field detector module may be required.

[0004] While the magnetic field detector modules described in the aforementioned applications are durable and reliable, it would be beneficial to increase the versatility of the implementation of the magnetic field detector modules in light of a variety of applications and operating environments. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the foregoing, it is an object of the present invention to provide a magnetic field detector module, particularly for use in current sensing applications, that is durable, reliable, versatile, and cost-effective to manufacture and use.

[0006] It would be advantageous to provide a magnetic field detector module that is accurate and compact.

[0007] It would be advantageous in certain applications to provide a magnetic field detector module that allows for some configuration of the module's operating and output characteristics during installation or use of the magnetic field detector module. [Means for solving the problem]

[0008] The object of the present invention is achieved by providing a magnetic field detector module according to claim 1. The dependent claims set out various advantageous features of embodiments of the invention.

[0009] Disclosed herein is a magnetic field detector module including a pair of magnetic field concentrators, an air gap formed between the pair of magnetic field concentrators, a magnetic field sensing cell mounted within the air gap, a plurality of terminals for interconnecting the magnetic field sensing cell to an external circuit, and an insulating housing in which the magnetic field concentrators, the magnetic field sensing cell, and the terminals are assembled.

[0010] The magnetic field detector module further includes a circuit board on which the magnetic field sensing cell is mounted, a portion of the circuit board inserted into the air gap, and each terminal having a substantially flat shape cut from a sheet of metal arranged substantially perpendicular to the circuit board and including an internal board connecting portion having a pair of opposing contacts separated by a slot, each contact engaging a respective side of the circuit board.

[0011] In an advantageous embodiment, said contact comprises at least one resilient arm on one side, which resiliently presses the contact against the circuit board.

[0012] In an advantageous embodiment, the contacts of the terminals are formed mirror-symmetrically.

[0013] In an advantageous embodiment, the contacts of each terminal form a tapered entrance portion that allows sliding insertion of the terminal onto a circuit board, the circuit board being guided into the slot during assembly of the magnetic field detector module.

[0014] In an advantageous embodiment, each terminal includes a securing portion in the form of barbs on an outer edge of the terminal which engage the sides of a cavity formed in the housing.

[0015] In an advantageous embodiment, each terminal includes an external board connection portion in the form of surface mount contacts arranged in mirror symmetry around the circuit board.

[0016] In an advantageous embodiment, the magnetic field concentrator includes a fixed guide that engages a complementary fixed guide in the housing.

[0017] In an advantageous embodiment, the fixed guide on the magnetic field concentrator is in the form of a keyhole slot within which a complementary key rail formed in the housing engages.

[0018] In an advantageous embodiment, the magnetic field sensing cell is in the form of an ASIC having electrical terminals in surface mount connection to circuit traces on a circuit board.

[0019] In an advantageous embodiment, the magnetic field sensing cell comprises a Hall effect sensor.

[0020] In an advantageous embodiment, the terminals are stamped from sheet metal.

[0021] In an advantageous embodiment, the substantially planar terminals are arranged in a juxtaposed parallel configuration relative to one another within the housing, with each terminal being inserted into a corresponding slot provided in the housing.

[0022] In an advantageous embodiment, the housing comprises a plastic molded part forming a shell defining a cavity therein within which the magnetic field concentrator, the circuit board with the sensing cells, and the terminals may all be assembled by being inserted in a common axial direction perpendicular to the mounting surface of the magnetic field detector module.

[0023] In an advantageous embodiment, a current transformer includes a magnetic core having a branch positioned adjacent an outer end of a magnetic field concentrator.

[0024] Further objects and advantageous features of the present invention will be apparent from the claims, the detailed description, and the accompanying drawings. [Brief explanation of the drawings]

[0025] [Figure 1a] 1 is a perspective view of a magnetic field detector module according to one embodiment of the present invention; [Figure 1b] 1 is a perspective view of a magnetic field detector module according to one embodiment of the present invention; [Figure 1c] 1 is a perspective view of a magnetic field detector module according to one embodiment of the present invention; [Figure 2a] FIG. 1B is a perspective view of the embodiment of FIGS. 1a-1c with the housing removed. [Figure 2b] FIG. 1B is a perspective view of the embodiment of FIGS. 1a-1c with the housing removed. [Figure 2c] 2b is a perspective view similar to FIG. 2a, but with a magnetic concentrator according to the deformation. [Figure 3] FIG. 2b is a perspective view of the embodiment of FIG. 2a with the magnetic concentrator removed. DETAILED DESCRIPTION OF THE INVENTION

[0026] Referring to the figure, the magnetic field detector module 1 includes an insulating housing or body 4, a pair of magnetic field concentrators 5 forming a magnetic field gap 7 (also commonly known as an air gap) therebetween, a magnetic field sensing cell 2 mounted within the air gap 7, a circuit board 8 on which the sensing cell is mounted, and a plurality of terminals 3.

[0027] The magnetic field sensing cell 2 may advantageously be in the form of an ASIC (Application Specific Integrated Circuit) including, for example, a Hall Effect magnetic field sensor. The sensing cell has terminals 18 connected to conductive circuit traces on a circuit board 8. Further electrical or electronic components may be mounted on the circuit board 8 for processing and transmitting power or signals between the sensing cell 2 and the terminals 3. The additional electrical or electronic components may be optional depending on the variant.

[0028] The circuit board 8 includes conductive circuit traces that serve to interconnect the sensing cells, and any further electrical or electronic components, if present on the circuit board, to their respective terminals 3 for communicating power and signals between the magnetic field detector module and the external circuitry to which the magnetic field detector module is connected.

[0029] The magnetic field detector module is particularly configured to be mounted and electrically connected to an external circuit board (not shown). In variants (not shown), the magnetic field detector module can be provided with terminals having plug-in or other form of contact portions for plug-in, clamp-on or other form of interconnection to an external system.

[0030] The magnetic field concentrator 5 may be made of FeSi material, which may be formed from stamped metal sheets, a plurality of which are stacked to form a laminated structure. Laminated structures are known per se in the field of magnetic armatures. The magnetic concentrator may be made of a ferrite material having high magnetic permeability, which is also known per se. In an embodiment, the magnetic concentrator may have a detector end 6b, which has a reduced surface area compared to the outer end 6a, allowing the concentrator to concentrate the magnetic flux through the sensing cell 2 positioned in the magnetic field gap 7 while reducing the risk of saturation in the magnetic core.

[0031] In an advantageous embodiment, the magnetic concentrator 5 may advantageously include a fixing guide, for example in the form of a keyhole slot 16, by means of which the concentrator can be inserted into a cavity 17 with a complementary guide, for example a key rail 15 formed inside the housing 4, to accurately position and fix the concentrator to the housing in a stable manner.

[0032] The housing 4 forms a shell having a cavity 17 accessible from at least one open side. In the illustrated embodiment, this open side is the mounting side of the magnetic field detector module, so that the magnetic field concentrator 5, circuit board 8, and terminals 3 may all be inserted into the housing 4 perpendicular to the mounting surface. This allows for cost-effective manufacture of the magnetic field detector module. An insulating potting material may optionally be filled into the cavity 17 once the components of the module are assembled within the housing.

[0033] The terminals 3 are advantageously formed of flat or substantially flat elements, which may be stamped, in particular from sheet metal. The terminals include an internal board connection portion 14 and an external board connection portion 12 for electrically interconnecting circuit traces on the circuit board 8 with circuit traces on an external circuit board (not shown) to which the magnetic field detector module is to be mounted. Each terminal 3 further includes a fixing portion configured to anchor the terminal inside the housing 4. The fixing portions may advantageously include barbs 14 configured to bite into the internal side walls of the housing 4, which may be made, for example, from injection-molded plastic.

[0034] The internal board connection portion 10 may advantageously include a pair of opposing contacts 9 forming a slot 11 therebetween into which the circuit board 8 is inserted. The contacts may advantageously be in the form of at least partially resilient contacts, for example cantilever contacts, having a particular resilience that ensures that the circuit board 8 is clamped between the contacts 9. The contacts 9 of the terminals may advantageously be formed as a mirror-symmetric pair, so that the terminals can be inserted into the housing after the circuit board 8 has been inserted therein, and the resilient contact arms 9 engage the circuit board 8 and electrically bias against contact pads that are connected to conductive circuit traces on the circuit board for electrically interconnecting the terminals 3 to the magnetic field sensing cell 2.

[0035] The substantially flat terminals 3, arranged perpendicular to the circuit board and the air gap 7, allow the terminals 3 to be arranged in a compact side-by-side arrangement within the housing 4. At the same time, this arrangement ensures easy assembly by axial insertion of the terminals into the housing, and excellent contact with conductive circuit traces on the circuit board 8, as a pair of at least partially resilient contacts 9 press against the circuit board.

[0036] By providing a circuit board 8 to interconnect the terminals 3 to the sensing cells 2, various sensing cell types and configurations can be mounted on the circuit board without requiring design changes to the terminals 3. Additionally, other electrical or electronic components can be mounted on the circuit board depending on the application and desired configuration. For example, a temperature sensor may be mounted on the circuit board. One or more electrical shielding layers can also be provided within the circuit board or around the contacts to reduce interference from external electric fields.

[0037] The external board connection portion 12 of the terminal 3 may be configured as a surface mount connection leg 13 for soldered or welded connection to an external circuit board. In variations, the external board connection portion 12 may also include a pin terminal for insertion into a through hole in a circuit board or for plug-in connection to a complementary connector.

[0038] The arrangement of the terminals, the circuit board with the magnetic sensing cells mounted thereon, and the magnetic field concentrator according to embodiments of the present invention also ensures cost-effective manufacturing due to the linear unidirectional insertion of the components inside the housing and simple assembly due to the particularly compact arrangement of the juxtaposed flat terminals, while at the same time ensuring a robust and stable interconnection.

[0039] [List of reference symbols used] Magnetic Field Detector Module 1 Sensing Cell 2 ASIC (e.g. Hall effect) Terminal 18 Terminal 3 Internal board connection part 10 Elastic arm contact 9 Slot 11 External board connection part 12 Surface mount connection contacts 13 (pin contact) fixed part Hanging 14 Insulating housing / body 4 Cavity 17 Magnetic concentrator fixed guide (key rail) 15 Magnetic Concentrator 5 Outer end 6a Detector end 6b Magnetic Gap 7 Fixed guide (slot) 16 Circuit board 8

[0040] [Embodiment] (1) A magnetic field detector module (1), a pair of magnetic field concentrators (5), an air gap (7) formed between the pair of magnetic field concentrators, a magnetic field sensing cell (2) mounted within the air gap, a plurality of terminals (3) for interconnecting the magnetic field sensing cell to an external circuit, and an insulating housing (4) in which the magnetic field concentrators, the magnetic field sensing cell, and the terminals are assembled; The magnetic field detector module further includes a circuit board (8) on which the magnetic field sensing cell is mounted, a portion of the circuit board being inserted into the air gap, and each terminal (3) has a substantially flat shape cut out from a sheet of metal arranged substantially perpendicular to the circuit board and includes an internal board connection portion having a pair of opposing contacts (9) separated by a slot (11), each contact engaging a respective side of the circuit board. (2) A magnetic field concentrator as described in embodiment 1, wherein the contact includes at least one resilient arm on one side, the resilient arm resiliently pressing the contact against the circuit board. (3) A magnetic field detector module according to embodiment 1 or 2, wherein the contacts (9) of the terminals are formed in mirror symmetry. (4) A magnetic field detector module as described in any one of embodiments 1 to 3, wherein the contacts (9) of each terminal (3) form a tapered entrance portion that allows the terminal to be slidably inserted onto the circuit board, and the circuit board is guided into the slot (11) during assembly of the magnetic field detector module. (5) A magnetic field detector module as described in any one of embodiments 1 to 4, wherein each terminal includes a fixing portion in the form of a barb (14) on an outer edge of the terminal, the barb engaging with a side of a cavity (17) formed in the housing (4).

[0041] (6) A magnetic field detector module as described in any one of embodiments 1 to 5, wherein each terminal includes an external substrate connection portion (12) in the form of a surface-mounted contact arranged in mirror symmetry around the circuit board (8). (7) A magnetic field detector module according to any one of claims 1 to 6, wherein the magnetic field concentrator (5) includes a fixed guide (16) that engages with a complementary fixed guide (15) in the housing (4). (8) A magnetic field detector module as described in embodiment 7, wherein the fixed guide on the magnetic field concentrator is in the form of a keyhole slot into which a complementary key rail formed in the housing engages. (9) A magnetic field detector module as described in any one of embodiments 1 to 8, wherein the magnetic field sensing cell is in the form of an ASIC having electrical terminals (18) surface-mounted and connected to circuit traces on the circuit board (8). (10) A magnetic field detector module as described in embodiment 9, wherein the magnetic field sensing cell includes a Hall effect sensor.

[0042] (11) A magnetic field detector module according to any one of embodiments 1 to 10, wherein the terminals are stamped from a sheet metal. (12) A magnetic field detector module as described in any one of embodiments 1 to 11, wherein the substantially flat terminals (3) are arranged in a parallel juxtaposed relationship to each other within the housing (4), and each terminal is inserted into a corresponding slot provided in the housing. (13) A magnetic field detector module as described in any one of embodiments 1 to 12, wherein the housing includes a plastic molded part forming a shell that defines a cavity (17) therein, and within the cavity, the magnetic field concentrator, the circuit board with the sensing cell, and the terminals can all be assembled by being inserted in a common axial direction perpendicular to the mounting surface of the magnetic field detector module. (14) A current converter, A current converter comprising a magnetic field detector module as described in any one of embodiments 1 to 13, wherein the current converter comprises a magnetic core having a branch positioned adjacent to the outer end (6a) of the magnetic field concentrator.

Claims

1. A magnetic field detector module (1), comprising: a pair of magnetic field concentrators (5), an air gap (7) formed between the pair of magnetic field concentrators, a magnetic field sensing cell (2) mounted within the air gap, a plurality of terminals (3) for interconnecting the magnetic field sensing cell to an external circuit, and an insulating housing (4) in which the magnetic field concentrators, the magnetic field sensing cell, and the terminals are assembled; the magnetic field detector module further comprises a circuit board (8) on which the magnetic field sensing cell is mounted, a portion of the circuit board being inserted into the air gap, each terminal (3) having a substantially flat shape cut out from a sheet of metal arranged substantially perpendicular to the circuit board, and including an internal board connection portion having a pair of opposing contacts (9) separated by a slot (11), each contact engaging a respective side of the circuit board; A magnetic field detector module, wherein each terminal comprises an external board connection portion (12) in the form of a surface-mounted contact arranged in mirror symmetry around said circuit board (8).

2. 2. The magnetic field detector module of claim 1, wherein the contact includes at least one resilient arm on one side, the resilient arm resiliently pressing the contact against the circuit board.

3. 2. A magnetic field detector module according to claim 1, wherein the contacts (9) of the terminals are formed mirror-symmetrically.

4. 2. The magnetic field detector module according to claim 1, wherein the contacts (9) of each terminal (3) form a tapered entrance portion that allows sliding insertion of the terminal onto the circuit board, the circuit board being guided into the slot (11) during assembly of the magnetic field detector module.

5. 2. The magnetic field detector module according to claim 1, wherein each terminal comprises a fixing portion in the form of a barb (14) on an outer edge of said terminal, said barb engaging a side of a cavity (17) formed in said housing (4).

6. 2. The magnetic field detector module of claim 1, wherein the magnetic field concentrator (5) includes a fixed guide (16) that engages a complementary fixed guide (15) in the housing (4).

7. the fixed guide on the magnetic field concentrator is in the form of a keyhole slot; The magnetic field detector module of claim 6 , wherein the complementary fixed guide is a key rail formed in the housing.

8. 2. The magnetic field detector module of claim 1, wherein the magnetic field sensing cell is in the form of an ASIC having electrical terminals (18) surface-mounted and connected to circuit traces on the circuit board (8).

9. The magnetic field detector module of claim 8 , wherein the magnetic field sensing cell comprises a Hall effect sensor.

10. 2. The magnetic field detector module according to claim 1, wherein the substantially flat terminals (3) are arranged in a juxtaposed parallel manner relative to one another inside the housing (4), each terminal being inserted into a corresponding slot provided in the housing.

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