Current sensor and method for producing a current sensor

Abstract

The invention relates to a current sensor (10) comprising an electrical conductor (14), comprising a first current measuring device (22) which has a first Hall sensor (26) that measures a change in the magnetic field of the current flowing through the electrical conductor (14), and a second current measuring device (24) which has a differential Hall sensor (34) that measures a change in the magnetic field of the current flowing through the electrical conductor (14), wherein the first current measuring device (22) comprises a magnetic core (30) extending around the electrical conductor (14), wherein the first Hall sensor (26) is located in an interruption (32) in the magnetic core (30), and wherein the differential Hall sensor (34) is located in a recess (36) in the electrical conductor (14). The invention further relates to a method for producing such a current sensor (10).

Description

[0001] Description

[0002] Current sensor and method for producing a current sensor

[0003] The invention relates to a current sensor, in particular a current sensor for a battery in a vehicle, and a method for producing such a current sensor.

[0004] Current sensors are used to measure the current flowing through an electrical line. In particular, such current sensors are used to measure the charging and discharging current of a battery, especially a vehicle battery, in order to determine the battery's state of charge. The current sensor has an electrical conductor arranged in series with the electrical loads and the battery, so that all charging and discharging currents flow through this electrical conductor.

[0005] On the one hand, the current sensor must have a very wide measuring range to be able to detect all currents occurring during normal operation. On the other hand, the current sensor must be sufficiently accurate to be able to measure the currents occurring in the electrical conductor very precisely, for example, to make an exact statement about the charge level of a battery. Furthermore, such a current sensor must be very robust to withstand the stresses encountered during normal operation. Furthermore, the current sensor should be simple and cost-effective to manufacture.

[0006] The object of the invention is to provide a current sensor which has a wide measuring range and provides a sufficiently high accuracy over the entire measuring range.

[0007] To achieve this objective, a current sensor with an electrical conductor is provided, comprising a first current measuring device comprising a first Hall sensor that measures a change in the magnetic field of the current flowing through the electrical conductor, and a second current sensor device comprising a differential Hall sensor that measures a change in the magnetic field of the current flowing through the electrical conductor. The first current measuring device comprises a magnetic core extending around the electrical conductor in the circumferential direction of the electrical conductor, wherein the first Hall sensor is arranged in an interruption of the magnetic core. Furthermore, the electrical conductor has a recess, and the differential Hall sensor is arranged in this recess.

[0008] Typically, such a current sensor uses two Hall sensors, each with its own magnetic core. However, previous current sensors require a relatively large installation space, as the magnetic cores each require a separate installation space and must be positioned next to each other on the electrical conductor. According to the present application, only one Hall sensor with one magnetic core is used. A second Hall sensor is installed in a recess in the electrical conductor as a so-called differential Hall sensor. Because it is positioned in the recess of the electrical conductor, this Hall sensor does not require a magnetic core.

[0009] In particular, the first Hall sensor and the differential Hall sensor can be positioned closer to each other due to the absence of a magnetic core in the differential Hall sensor, which can further reduce the installation space.

[0010] A further advantage of the above-described design is that the two Hall sensors have different measuring ranges. The first Hall sensor has greater sensitivity and accuracy due to the magnetic core, allowing it to measure small currents with very high accuracy. The differential Hall sensor has a larger measuring range, making it suitable for measuring larger currents or currents across the entire measuring range. In particular, the differential Hall sensor can be used to verify the measurement results of the first Hall sensor when the currents are within the measuring ranges of both Hall sensors.

[0011] Since the first Hall sensor and the differential Hall sensor can be positioned closer together, the first Hall sensor and the differential Hall sensor can be arranged on a common circuit board, for example. This can reduce assembly effort, as both Hall sensors can be mounted and positioned with the assembly of the common circuit board.

[0012] For example, the circuit board can extend with the differential Hall sensor into the recess of the electrical conductor, and with the first Hall sensor into the interruption of the magnetic core. In particular, when mounted, the first Hall sensor and the differential Hall sensor lie on a common plane that extends through the recess of the electrical conductor and the interruption of the magnetic core. This allows for easy positioning of the two Hall sensors on a circuit board.

[0013] The recess preferably extends in a longitudinal direction of the electrical conductor, and the circuit board preferably also extends in the longitudinal direction of the electrical conductor. As a result, a portion of the circuit board can extend into the recess and is oriented such that the circuit board can further extend toward the magnetic core of the first Hall sensor, which is arranged, in particular, in front of or behind the differential Hall sensor or the recess in the longitudinal direction.

[0014] In particular, the recess of the electrical conductor and the interruption of the magnetic core can be located on a common plane, with the printed circuit board extending in this plane.

[0015] The plane preferably extends in the longitudinal direction of the electrical conductor and at right angles to the plane of the electrical conductor. This means that the circuit board is perpendicular to the electrical conductor, allowing it to be easily inserted into the recess. Since the interruption in the magnetic core also extends in this plane at right angles to the plane of the electrical conductor, the circuit board can be inserted into both the recess of the electrical conductor and the interruption in the magnetic core.

[0016] The first Hall sensor and the differential Hall sensor can be arranged offset in the longitudinal direction of the electrical conductor, so that they are also arranged offset on the circuit board.

[0017] The circuit board can have centering elements to align the circuit board in the recess and / or on the magnetic core. This can facilitate the mounting of the circuit board on the electrical conductor and thus the positioning of the first Hall sensor in the interruption of the magnetic field or the differential Hall sensor in the recess of the electrical conductor. For example, the centering elements can be stops that limit the insertion of the circuit board and thus define the position of the circuit board relative to the electrical conductor and the magnetic core.

[0018] Furthermore, the circuit board can have fixing elements to secure the circuit board in the recess and / or to the magnetic core. Once positioned on the electrical conductor and the magnetic core, the circuit board can be fixed in place, preventing the position of the circuit board and thus the Hall sensors from changing.

[0019] To achieve the object, a method for producing a current sensor as described above is further provided, which comprises the following steps:

[0020] - Providing an electrical conductor, wherein the electrical conductor has a recess for the differential Hall sensor running in the longitudinal direction of the electrical conductor,

[0021] - Positioning a magnetic core extending in the circumferential direction around the electrical conductor, wherein the magnetic core has an interruption for the first Hall sensor, - Providing and positioning a circuit board on which the first Hall sensor and the second Hall sensor are provided, wherein the first Hall sensor is positioned in the interruption of the magnetic core and the differential Hall sensor is positioned in the recess of the electrical conductor.

[0022] Preferably, the circuit board is inserted into the recess and the interruption in a plane extending through the longitudinal direction of the electrical conductor and a direction extending at right angles to the plane of the electrical conductor.

[0023] In particular, the printed circuit board can be inserted until the printed circuit board rests with centered elements on the electrical conductor, in particular the recess of the electrical conductor, and / or on the magnetic core.

[0024] Further advantages and features can be found in the following description in conjunction with the attached drawings. These show:

[0025] Figure 1 shows a first perspective view of a current sensor according to the invention;

[0026] Figure 2 shows a detailed view of the current sensor from Figure 1;

[0027] Figure 3 is a second perspective view of the current sensor of Figure 1; and

[0028] Figure 4 shows a third perspective view of the current sensor from Figure 1 .

[0029] Figures 1 to 4 show a current sensor 10 for measuring a current flowing through an electrical conductor 14. The electrical conductor 14 can, for example, be arranged with the terminals 16, 18 in the electrical circuit of a vehicle, with a vehicle battery being connected to one of the terminals 16, 18 and vehicle loads being connected to the other terminals 16, 18, so that the entire charging and discharging current of the battery flows through the electrical conductor and can be detected by the current sensor 10. For example, the current sensor 10 is part of a battery sensor that detects other operating parameters of the battery.

[0030] The current sensor 10 has a circuit board 20 on which a first current measuring device 22 and a second current measuring device 24 are provided.

[0031] The first current measuring device 22 has a first Hall sensor 26, which, as can be seen in Figure 3, is now arranged outside the plane of the electrical conductor 12, in particular on an underside 28 of the electrical conductor. The first current measuring device 22 further has an annular magnetic core 30 that extends in a circumferential direction U around the electrical conductor 12. The magnetic core 30 has an interruption 32, which, as can be seen in particular in Figures 3 and 4, is arranged on the underside 28 of the electrical conductor 12, with the first Hall sensor 26 being arranged in this interruption 32.

[0032] The second current measuring device 24 has a differential Hall sensor 34, which is provided in an elongated recess 36 in the electrical conductor 12.

[0033] The two current measuring devices 22, 24 are arranged one behind the other in the longitudinal direction L of the electrical conductor 12, i.e., in the current direction, and thus measure the same current. The two current measuring devices 22, 24 thus enable redundant current measurement of the current flowing through the electrical conductor 12.

[0034] The magnetic core 30 amplifies the magnetic field generated by the current flowing through the electrical conductor 14, so that the first Hall sensor or the first current measuring device has a higher sensitivity, i.e. is better suited for measuring small currents.

[0035] Due to the position of the differential Hall sensor 34 within the electrical conductor, a sufficiently strong magnetic field is also generated for this Hall sensor 34 to measure the currents. This differential Hall sensor 34 is fundamentally suitable for measuring larger currents. As can be seen in Figures 1 to 4, both Hall sensors 26, 34 are provided on a common circuit board 20. The circuit board 20 extends in the longitudinal direction L of the electrical conductor 12, with the plane of the circuit board 12 further extending perpendicular to the transverse direction of the electrical conductor 12. Furthermore, a communication interface 38 is provided on the circuit board 20 in order to be able to output the measured values ​​of the two current measuring devices 22, 24, for example to a vehicle control system. In addition, further components, for example signal amplifiers, signals and converters or analog-to-digital converters, can be provided on the circuit board 20.

[0036] As can be seen in particular in Figures 1 and 2, the elongated recess 36 extends in the longitudinal direction L over both the first current measuring device 22 and the second current measuring device 24. The length of the printed circuit board 20 in the longitudinal direction L corresponds to the length of the recess 36 or is slightly shorter than this.

[0037] To assemble the current sensor 10, the electrical conductor 14 is first provided, wherein the electrical conductor 14 has the elongated recess 36. The magnetic core 30 is then positioned, for example, pushed onto the electrical conductor 14 in the longitudinal direction L. Once the electrical conductor 14 is in the desired position of the first current measuring device 22, the circuit board 20 can be pushed into the recess 36 in an assembly device perpendicular to the plane of the electrical conductor 14 until the first Hall sensor 24 and the differential Hall sensor 34 are in the desired position in the interruption 32 and 34, respectively.

[0038] As can be seen particularly in Figures 1 and 2, the circuit board has a groove that functions as a centering element 40 for the magnetic core 30. As soon as the magnetic core 30 rests in the groove, the first Hall sensor 26 is in the desired position in the interruption 32 of the magnetic core 30. Furthermore, the circuit board 20 widens in steps with the section facing the underside 28, so that the steps form further centering elements that rest on the underside 28 of the electrical conductor 14 and thus prevent the circuit board 20 from being inserted too far. This ensures that the differential Hall sensor 34 is also in the desired position in the recess 36.

[0039] Furthermore, additional centering elements can be provided to determine the position of the circuit board 20 and thus the Hall sensors 26, 34. Furthermore, fixing elements, such as locking elements, can also be provided to reliably fix the circuit board 20 in position in the recess 36. Furthermore, holding means for the current sensor 10 in the vehicle or a housing that protects the Hall sensors 26, 34 from external influences or mechanical stresses can also be provided.

Claims

Patent claims 1. A current sensor (10) with an electrical conductor (14), with a first current measuring device (22) which has a first Hall sensor (26) which measures a change in the magnetic field of the current flowing through the electrical conductor (14), and with a second current measuring device (24) which has a differential Hall sensor (34) which measures a change in the magnetic field of the current flowing through the electrical conductor (14), wherein the first current measuring device (22) has a magnetic core (30) extending around the electrical conductor (14), and wherein the first Hall sensor (26) is arranged in an interruption (32) of the magnetic core (30), and wherein the differential Hall sensor (34) is arranged in a recess (36) of the electrical conductor (14).

2. Current sensor according to claim 1, characterized in that the first Hall sensor (26) and the differential Hall sensor (34) are arranged on a common printed circuit board (20).

3. Current sensor according to claim 2, characterized in that the printed circuit board (20) with the differential Hall sensor (34) extends into the recess (36) of the electrical conductor (20) and extends with the first Hall sensor (26) into the interruption (32) of the magnetic core (30).

4. Current sensor according to claim 3, characterized in that the recess (36) extends in a longitudinal direction (L) of the electrical conductor (20), and that the printed circuit board (20) extends in the longitudinal direction (L) of the electrical conductor (20).

5. Current sensor according to one of claims 2 to 4, characterized in that the recess (36) of the electrical conductor (20) and the interruption (32) of the magnetic field (30) are located on a common plane, the printed circuit board (20) extending in this plane.

6. Current sensor according to claim 5, characterized in that the plane extends in the longitudinal direction (L) of the electrical conductor (20) and at right angles to the plane of the electrical conductor (20).

7. Current sensor according to one of claims 2 to 6, characterized in that the first Hall sensor (26) and the differential Hall sensor (34) are arranged offset in the longitudinal direction (L) of the electrical conductor (20).

8. Current sensor according to one of claims 2 to 7, characterized in that the circuit board (20) has centering elements (40, 42) in order to align the circuit board (20) in the recess (36) and / or on the magnetic core (30).

9. Current sensor according to one of claims 2 to 8, characterized in that the circuit board (20) has fixing elements in order to fix the circuit board (20) in the recess (36) and / or on the magnetic core (30).

10. A method for producing a current sensor (10) according to any one of the preceding claims, the method comprising the following steps: - Providing an elongated electrical conductor (14), wherein the electrical conductor (14) has a recess (36) extending in the longitudinal direction (L). - positioning a magnetic core (30) with an interruption (32), wherein the magnetic core (30) is positioned such that the interruption (32) is located on a plane extending perpendicular to the plane of the electrical conductor (14) and in the longitudinal direction (L) of the electrical conductor (14), and - Inserting a printed circuit board (20) with a first Hall sensor (26) and a differential Hall sensor (34) in a mounting device (M) perpendicular to the plane of the electrical conductor (14) into the recess (36) until the first Hall sensor (26) is in the interruption (32) and the differential Hall sensor (34) is in the recess (36).

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