EP4792143A1

EP4792143A1 - Current monitoring in a wire within an electrical connector

Info

Publication number: EP4792143A1
Application number: EP24786050.5A
Authority: EP
Inventors: Vianney GRENEZ; Vivek R. Dave
Original assignee: Harting International Innovation AG
Current assignee: Harting International Innovation AG
Priority date: 2023-10-11
Filing date: 2024-10-02
Publication date: 2026-08-19
Also published as: WO2025078243A1; CN122003609A

Abstract

Current detection device for a wire, comprising a sleeve of a flexible material, wherein the sleeve is tubular and is arranged to be fitted over part of a wire; an inductor including a first coil of a first wire formed from a conductive material carried by the sleeve, and a second coil of a second wire provided on the first wire, the second coil is helical in shape and has a first end extending to a first end of the second wire, and the second coil has a second end extending to a second end of the second wire; and an integrator circuit coupled to the first end of the second wire and to the second end of the second wire and providing an output voltage that varies as a function of the magnitude of a current in the coil.

Description

CURRENT MONITORING IN A WIRE WITHIN AN ELECTRICAL CONNECTOR

Technical Field

[0001] The present disclosure relates generally to electrical connectors and to a device for measuring current within a wire of an electrical connector. In particular, the present disclosure relates to a current detection device for a wire and to an electrical connector comprising said device. Also, the present disclosure relates to a method of making said current detection device.

Background Art

[0002] An electrical connector is a device that allows electrical current to flow between two or more electrical circuits. It provides a secure and reliable connection for the transfer of power or signals. Electrical connectors come in various types, shapes, and sizes, depending on the specific application and requirements. In an electrical connector, wires play a crucial role in establishing the electrical connection between the connector and the device it is connected to. The wires are used to carry electrical signals or power between the two mating connectors.

[0003] In some situation, it is useful to measure and/or monitor the current flowing within a wire in an electrical connector. For example, measuring the current can help to identify any faults or abnormalities within the circuit. If the measured current deviates significantly from the expected or normal range, it could indicate a short circuit, overload, or other issues that need to be addressed. Measuring the current can also allow for the evaluation of the circuit's performance. It helps determine if the current flowing through the wire is within the desired range and if the circuit is functioning as intended. Furthermore, by comparing the measured current with the expected values at different points in the circuit, it can help pinpoint the location of a fault or identify components that are not functioning correctly. In certain applications, such as electrical installations or industrial settings, measuring the current can be necessary to ensure compliance with safety regulations and standards.

[0004] Several techniques can be used to monitor the current flowing in the wires of an electrical connector. For examples, current data loggers can be connected in series with the wire within the electrical connector to continuously measure and record current values over a specific period. These loggers store the data internally, which can later be downloaded and analyzed to understand the current profile and trends. Some electrical connectors may have built-in current monitoring modules which typically include current sensing circuitry and interfaces for data acquisition or communication. They allow for real-time monitoring and reporting of current values within the electrical connector. Power monitoring systems can also be used to monitor various electrical parameters, including current, voltage, power, and energy consumption. These systems often include current sensors or transducers that can be installed in the wires of the electrical connector to provide continuous monitoring of current. However, these known solutions could be very expensive or complicated to manufacture and are not always accurate, especially for monitoring wires that are bent or manipulated during connection in an electrical connector.

Disclosure of the Invention

[0005] According to a first aspect, a current detection device for a wire is provided. The current detection device comprises a sleeve of a flexible material, wherein the sleeve is tubular and is arranged to be fitted over part of a wire; an inductor including a first coil of a first wire formed from a conductive material carried by the sleeve, and a second coil of a second wire provided on the first wire, the second coil is helical in shape and has a first end extending to a first end of the second wire, and the second coil has a second end extending to a second end of the second wire; and an integrator circuit coupled to the first end of the second wire and to the second end of the second wire and providing an output voltage that varies as a function of the magnitude of a current in the coil.

[0006] According to a second aspect, an electrical connector is provided, said electrical connector having a housing and a plurality of wires with a portion of each wire received within the housing, wherein a current detection device of the first aspect is on said portion of at least one of the wires.

[0007] According to a third aspect, method of making a current detection device for a wire is provided. The method comprises: providing a first wire of a conductive material; printing a second wire of a conductive material in a coil onto the first wire, forming the first wire into a coil either before or after the printing step, where the second wire has a diameter of between 0.001mm² and 0.9mm², and the second coil has a helical shape having a pitch of between 0.4 degrees and 45 degrees.

[0008] Other aspects and features are defined in the appended claims.

[0009] Examples of the disclosure may make it possible to obtain a current detection device for a wire that is easy to manufacture and that improves the accuracy of current detection signal. Brief Description of the Drawings

[0010] The following detailed description of preferred implementations and best mode will be set forth with regard to the accompanying drawings, in which:

[0011] FIG. 1 illustrates a perspective, partially sectioned view of an electrical connector shown in a connected state;

[0012] FIG. 2 illustrates the connector of FIG. 1 in a disconnected state;

[0013] FIG. 3 is a diagrammatic view of the electrical connector showing multiple wires of a cable coupled to the electrical connector;

[0014] FIG. 4 is a view of a sleeve including a current detecting inductor;

[0015] FIG. 5 is a cross-sectional view of a wire including the inductor;

[0016] FIG. 6 is a diagram of an integrator circuit to which the inductor is connected; and [0017] FIG. 7 is an enlarged, fragmentary view of a portion of the inductor showing a wire of a first coil with a second coil of a different wire wrapped around the wire of the first coil.

Detailed Description of Illustrative Embodiments

[0018] Referring in more detail to the drawings, FIGS. 1-3 illustrate an electrical connector 10 having a first part 12 and a second part 14 that are releasably coupled together to define an electrical connection between the parts. The first and second parts 12, 14 of the electrical connector 10 may each include a housing in which multiple connectors 16 are received, each having mating engagement features, which may include male and female structures, like a plug/insert and a socket that receives the plug/insert. Each of the multiple connectors includes electrical contacts arranged, as desired, to passthrough power or data or both, when the first and second parts are coupled together, and wires 18 from each connector may extend in a common cable 20 (FIG. 1), if desired. One example of such an electrical connector is the Han-

Modular® connector, sold by Harting Technology Group, and may include dozens of wires leading to a like number of electrical contacts of one or more internal connectors. In other arrangements, the electrical connector may be a single connector and not a modular grouping of connectors, with the connector including first and second parts 12, 14 with associated electrical contacts that are electrically coupled together when the two parts 12, 14 are slidably connected together.

[0019] As shown in FIG. 3, the connector parts 12, 14 may be coupled to separate components, like a cable 20 and a circuit board 22 or otherwise, as desired to electrically connect the components through the connector 10. The connector 10 provides multiple passthrough connections, and may have any desired number of electrical contacts. The simplified diagram in FIG. 3 shows five pins or electrical contacts 24 each associated with a separate one of the wires 18. The pins or contacts 24 of each part 12, 14 of the connector 10 engage each other to define passthrough electrical connections. Of course, these pins or electrical contacts are merely representative and any number of contacts 24 and wires 18 may be used, in any desired arrangement.

[0020] As noted above and best shown in FIG. 1, the cable 20 includes multiple individual wires 18 within an outer cable sheath 26. Each wire 18 may lead to a separate contact 24 of the connector part 14, and, as shown in FIG. 5, the wires 18 may each include a conductive core 28, usually of copper, within an insulating layer 30 of a non-conductive material, usually a polymer. The cable sheath 26 may be coupled to the connector part 14 and the individual wires 18 may extend out of the sheath and into an interior of a housing 32 of the connector part 12, as generally shown in FIG. 1. The wires 18 may be individually routed to and connected to respective contacts 24 of the connector part 14.

[0021] To enable detection of an alternating current in a wire 18 of the cable 20, a current detecting inductor 34 is provided around part of a wire 18. In FIG. 1, a wire 18 is shown with a current detecting inductor 34 on part of the wire 18. As shown in FIG. 4, the inductor 34 is formed from an electrically conductive material, like copper, and includes a first coil 36 of a conductive wire that is arranged in a helix that encircles and extends along an axial length of the wire 18, where the axis is a central axis 38 of the helix. The wire of the first coil 36 includes an insulative layer 37 surrounding the conductive inner wire material. Additionally, as shown in FIGS. 4 and 7, the inductor 34 includes a second coil 39 of conductive wire that is arranged in a helix around the wire of the first coil 36, where the helix of the second coil 39 has an inner diameter about equal to the outer diameter of the wire of the first coil 36 (including the insulative layer 37). First and second ends 40, 42 of the second coil 39 are coupled to an integrator circuit 44, with part of the wire (e.g. a return lead 45) of the second coil 39 passing radially within the first coil 36, such as in a Rogowski Coil.

[0022] In at least some implementations, the inductor 34 including the first and second coils 36, 39, is provided on a tubular sleeve 46 that is then fitted onto a wire 18, over the insulating layer 30 of the wire 18, as shown in FIG. 5. The sleeve 46 may be formed of a flexible material to permit the sleeve 46 and inductor 34 to bend as the wire 18 is bent. Representative but non-limiting materials for the sleeve 46 include various flexible plastics, or rubber-based or rubber-like materials, such as PVC, TPU, any elastomer, and silicone. The sleeve 46 and the inductor 34 on the sleeve may have any desired axial length, with some implementations including an axial length of between 1cm and 10cm, where the axis referred to is the axis of the wire 18. In at least some implementations, the sleeve 46 has an inner diameter sized to permit the sleeve to be slid onto the outer surface of the insulating layer 30 of the wire 18, such as between 1 to 2 times the outer diameter of the wire, and a thickness of between 0.3mm and 1cm. The inner diameter of the helix of the first coil 36 is about equal to the outer diameter of the sleeve 46, in this embodiment.

[0023] In at least some implementations, the inductor 34 may be applied to an outer surface 48 of the sleeve 46 in a helical pattern. A first end 50 of the first coil 36 may be closer to a first end 52 of the sleeve 46 than to a second end 54 of the sleeve, and a second end 56 of the first coil 36 may be closer to the second end 54 of the sleeve than to the first end 52. In at least some implementations, a return lead 45, including a portion of the wire of the second coil 39 extending between the second end 56 of the first coil 36 to the second end 42 of the wire of the second coil 39, extends from the second end 56 of the first coil 36, radially inwardly into the interior of the sleeve 46 and back out of the first end 52 of the sleeve so that the second end 42 of the wire of the second coil 39 can be connected to the integrator circuit 44 and define a complete circuit. In at least some implementations, the second coil 39 of the inductor 34 is applied by 3D printing of the copper wire material onto the wire of the first coil 36. The 3D printing process may permit a desired wire cross- sectional area and helix pitch or pitch range to be maintained along the axial length of the second coil 39 which can improve the accuracy of the current detection signal provided by the inductor 34. Further, the sleeve material can ensure that the inductor 34 has a constant diameter. The inductor 34 could be overmolded by the material of the sleeve 6 (e.g. by dipping or otherwise providing the sleeve material onto an inductor), the inductor could be adhered to a sleeve of polymeric or cloth material, or the inductor could be otherwise provided on or in the material of the sleeve.

[0024] In at least some implementations, the material of the second coil 39 is applied as a cylindrical wire, that is, circular in cross-section, although other shapes may be used including oval, a rounded rectangle, or rectangle. In at least some implementations, the wire of the first coil 36 may have a cross-sectional area between 0.01mm² and 0.5mm², and the wire of the second coil 39 may have a cross-sectional area between 0.001mm² and 0.9mm². Further, in at least some implementations, the pitch of the helix of the first coil 36 may be between 1 degree and 60 degrees, with a maximum deviation in the pitch of about 10 degrees along the length of the first coil 36, and the pitch of the helix of the second coil 39 may be between 0.4degrees and 45 degrees, with a maximum deviation in the pitch of about 10 degrees along the length of the second coil 39.

[0025] In at least some implementations, such as is shown in FIG. 5, a shield or shield layer 60 may be provided over the sleeve 46 and inductor 34, to reduce the effects of magnetic fields from other wires interfering with the current detection of a selected wire 18. The shield layer 60 may be formed of any suitable material and may be 3D printed over the sleeve 46 with the inductor 34 thereon, or the sleeve 46 with the inductor 34 thereon may be overmolded by a shield layer 60 (e.g. by dipping or otherwise providing the sleeve material onto an inductor), or the shield layer may be slidably placed over the sleeve, as desired. The shield layer 60 may be formed of any suitable material to damp, attenuate or inhibit an outside magnetic field from reaching the inductor 34, and the shield layer 60 may also help contain or concentrate the magnetic field generate by the selected/intended wire 18 to improve current detection in the selected/intended wire. The shield layer 60 may be formed from aluminum or other metal.

[0026] The integrator circuit 44 may be arranged as known with regard to Rogowski coils, including passive and active integrators. A simple, active integrator circuit 44 is shown in FIG. 6, and includes an amplifier 62 having a negative terminal 64 connected to an input resistor 66, a positive terminal 68 connected to ground, and an RC element including a resistor 70 and a capacitor 72 connected in parallel in the feedback path of the amplifier 62.

[0027] In use, when alternating current is applied to the wire 18, a magnetic field is generated that induces current in the inductor 34, which is provided as an input to the integrator circuit 44 which provides a voltage at output 74 that varies as a function of the magnitude of the current induced in the inductor 34. In this way, the magnitude of the alternating current in the wire 18 can be determined.

[0028] Desirably, the inductor 34 can be provided very close to the exterior surface of the insulating layer 30 of the wire 18, so that individual wires 18 among multiple wires can have current monitoring capability in a relatively small space, such as within a housing or body of an electrical connector. Known Rogowski coils are large and include a large air gap between the Rogowski coil and the wire for which current is being determined/detected. The magnetic field is then weaker at the Rogowski coil and to overcome this, additional coils are provided which makes the device even larger. In at least some implementations, the inductors 34 described herein are very close to the wire 18 being monitored and may be on a sleeve 46 that is directly on the outer surface 30 of the wire 18. So arranged, the strength of the magnetic field is increased in the area of the closely provided inductor 34 and the sensitivity of the device is improved.

[0029] Further, with 3D printed coils 39, the size of the coil wire and the pitch of the coil shape of the second coil 39 can be reliably and repeatably achieved within tight tolerances to improve the accuracy of current monitoring across a production run of current detecting inductors 34. In one non-limiting example, the printed wire of the second coil 39 may be as small as 50 microns in diameter and the pitch of the helix may be as small as 50 microns, enabling a high number of windings per unit/axial length of the second coil. The accuracy of 3D printing or other material deposition process may be better than mechanically winding an already formed wire, although such a process may be used. Also, the flexible nature of the sleeve permits the inductor to be used on wires 18 that may be bent or otherwise manipulated during connection in an electrical connector.

[0030] All terms used in the claims are intended to be given their broadest reasonable construction and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as "a," "the," "said," etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

Claims

1. A current detection device for a wire, comprising: a sleeve of a flexible material, wherein the sleeve is tubular and is arranged to be fitted over part of a wire; an inductor including a first coil of a first wire formed from a conductive material carried by the sleeve, and a second coil of a second wire provided on the first wire, the second coil is helical in shape and has a first end extending to a first end of the second wire, and the second coil has a second end extending to a second end of the second wire; and an integrator circuit coupled to the first end of the second wire and to the second end of the second wire and providing an output voltage that varies as a function of the magnitude of a current in the coil.

2. The device of claim 1 wherein the second coil is formed by 3D printing of the second wire.

3. The device of claim 2 wherein the second wire is formed from copper.

4. The device of claim 1 wherein the first wire has a cross-sectional surface area of between 0.01mm² and 0.5mm², and the second wire has a cross-sectional surface area of between 0.001mm² and 0.9mm².

5. The device of claim 4 wherein the first coil has a pitch of between 1 degree and 60 degrees, and the second coil has a pitch of between 0.4 degrees and 45 degrees.

6. The device of claim 1 wherein the second coil has a pitch of between 0.4 degrees and 45 degrees, and the second wire has a cross-sectional surface area of between 0.001mm² and 0.9mm².

7. The device of claim 1 wherein the first coil has a first end adjacent to a first end of the sleeve and the first coil has a second end adjacent to a second end of the sleeve, a portion of the second wire between the second end of the first coil and the second end of the second wire extends within the interior of the sleeve and is accessible at the first end of the sleeve.

8. An electrical connector having a housing and a plurality of wires with a portion of each wire received within the housing, wherein a current detection device of claim 1 is on said portion of at least one of the wires.

9. A method of making a current detection device for a wire, comprising: providing a first wire of a conductive material; printing a second wire of a conductive material in a coil onto the first wire, forming the first wire into a coil either before or after the printing step, where the second wire has a diameter of between 0.001mm² and 0.9mm², and the second coil has a helical shape having a pitch of between 0.4 degrees and 45 degrees.

10. The method of claim 9 which also includes providing a sleeve about which the first coil is received.

11. The method of claim 10 which includes the steps of providing a first end of the second wire spaced from a first end of the sleeve; providing a first end of the first coil adjacent to a first end of the sleeve; providing a second end of the first coil adjacent to a second end of the sleeve; and providing a second end of the second wire, and a portion of the second wire that extends from the second end of the first coil to the second end of the second wire is received within an interior of the sleeve.