Magnetic field detection device

Abstract

The application provides a magnetic field detection device for detecting a magnetic field generated by an external magnetic source, which comprises a magnetic sensor; and further comprises a magnetic concentrator arranged between the external magnetic source and the magnetic sensor; the magnetic concentrator is made of magnetic material and the edge thereof is aligned with the sensing area of the magnetic sensor. The application can obtain the best magnetic concentration effect by arranging the magnetic concentrator and aligning the edge thereof with the sensing area of the magnetic sensor. The magnetic concentrator with the specific structure can concentrate the magnetic field generated by the original current and increase the Hall sensing output.

Description

Technical Field

[0001] This invention relates to the field of measurement technology, and in particular to a magnetic field detection device. Background Technology

[0002] In existing technologies, fully integrated current sensors utilize two Hall effect sensors to sense the primary current and generate a magnetic field to detect the current magnitude. To obtain a larger primary current density, the primary structure size must be reduced to increase the magnetic field. However, this approach increases primary impedance and thermal deformation, directly or indirectly affecting measurement accuracy and zero-point stability. Another method involves directly amplifying the Hall output signal using an IC circuit. This amplification directly amplifies noise, impacting zero-point stability. For low-current detection applications, most open-loop integrated current sensors are unsuitable. Improving the sensitivity of current sensors, linear magnetic sensors, gear sensors, and angle sensors is also crucial. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to improve the sensitivity of the sensor by concentrating the physical field of the magnet to achieve the equivalent amplification effect of the ASIC circuit, and avoid the zero-point noise fluctuation caused by the circuit amplification, thereby providing a magnetic field detection device technology suitable for low current detection applications.

[0004] To address the aforementioned problems, the present invention provides a magnetic field detection device for detecting a magnetic field generated by an external magnetic source. The device includes a magnetic sensor and further includes a magnetizing body disposed between the external magnetic source and the magnetic sensor. The magnetizing body is made of magnetic material, and its edges are aligned with the sensing area of ​​the magnetic sensor.

[0005] This invention achieves optimal magnetic focusing by aligning the edges of a magnetizing element with the sensing area of ​​a magnetic sensor. This specific magnetizing element structure concentrates the primary current to generate a magnetic field, thereby increasing the Hall effect sensor output. Attached Figure Description

[0006] Appendix Figure 1 The diagram shown is a structural schematic of the magnetic field detection device according to a specific embodiment of the present invention.

[0007] Appendix Figure 2 The diagram shown is a structural schematic of the magnetic field detection device according to a specific embodiment of the present invention.

[0008] Appendix Figure 3 The diagram shown is a structural schematic of the magnetic field detection device according to a specific embodiment of the present invention.

[0009] Appendix Figure 4 The diagram shown is a structural schematic of the magnetic field detection device according to a specific embodiment of the present invention.

[0010] Appendix Figure 5 The diagram shown is a structural schematic of the magnetic field detection device according to a specific embodiment of the present invention.

[0011] Appendix Figure 6 The figure shows a comparison of the magnetic field distribution before and after the magnetic field detector is equipped with a magnet in a specific embodiment of the present invention.

[0012] Appendix Figure 7 The figure shows a comparison of the magnetic field strength before and after setting the magnet at different sizes according to a specific embodiment of the present invention. Detailed Implementation

[0013] The specific embodiments of the magnetic field detection device provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0014] Appendix Figure 1 The diagram shown is a structural schematic of a magnetic field detection device according to a specific embodiment of the present invention. In this specific embodiment, the magnetic field detection device is an integrated current sensor. (See attached diagram.) Figure 1 As shown, the device includes a magnetic sensor 11 and a magnetizing element 12 for detecting the magnetic field generated by an external magnetic source 13. In this specific embodiment, the magnetic source 13 is a current source.

[0015] In this specific embodiment, the magnetizing body 12 and the external magnetic source 13 are disposed on opposite sides of the magnetic sensor 11. The magnetizing body 12 is a magnetic material selected from soft magnetic materials, such as iron, nickel, cobalt, and their alloys, and is manufactured using methods selected from electroplating, vacuum sputtering, embedding processes, and molding patches. The magnetic sensor 11 is selected from any of the following: horizontal Hall sensor, vertical Hall sensor, AMR, GMR, and TMR. The edge of the magnetizing body 12 is within the sensing area of ​​the magnetic sensor 11. In other specific embodiments, the edge of the magnetizing body 12 may also be aligned with the sensing area of ​​the magnetic sensor 11. Both methods can achieve the best magnetizing effect. The magnetizing body 12 with the above-described specific structure concentrates the primary current to generate a magnetic field, increasing the Hall sensing output.

[0016] In a preferred embodiment, the magnetizer 12 is rectangular, with its height greater than the higher of its length and width. The direction of the height refers to the axial direction of the line connecting the external magnetic source 13 and the magnetic sensor 11, with the plane perpendicular to this direction being the cross-sectional direction. For example, the cross-section of the magnetizer 12 can be set to a square with a side length ranging from 0.2 mm to 0.5 mm, and the corresponding height should be greater than the side length.

[0017] In another specific embodiment, the magnetizing body 12 may also be circular, elliptical, or polygonal, with its height greater than the lateral dimension of its cross-section. The lateral dimension refers to the diameter of the circle, the major axis of the ellipse, and the maximum lateral width of the polygon. The direction of the height refers to the axial direction of the line connecting the external magnetic source 13 and the magnetic sensor, with the plane perpendicular to it being the cross-sectional direction.

[0018] Appendix Figure 2 The diagram shows a schematic representation of a magnetic field detection device according to a specific embodiment of the present invention. It includes a magnetic sensor 11 and a magnetizing element 22, used to detect the magnetic field generated by an external magnetic source 13. In this embodiment, the magnetizing element 22 and the external magnetic source 13 are disposed on the same side of the magnetic sensor 11, which can also concentrate the primary current to generate a magnetic field and increase the Hall effect sensor output.

[0019] Appendix Figure 3 The diagram shows a schematic of a magnetic field detection device according to a specific embodiment of the present invention. It includes a magnetic sensor 11 and magnetizing bodies 32a and 32b, used to detect the magnetic field generated by an external magnetic source 13. In this embodiment, multiple magnetizing bodies are used, and they are positioned on the opposite side of the magnetic sensor 11 from the external magnetic source 13. This allows for the concentration of primary-side current to generate a magnetic field, increasing the Hall effect output. The edges of magnetizing bodies 32a and 32b are both within the sensing area of ​​the magnetic sensor 11. Magnetizing bodies 32a and 32b are symmetrically arranged with respect to the center of the magnetic sensor 11, avoiding unilateral amplification of external magnetic interference. Since the magnetic sensor 11 typically uses multiple symmetrically arranged sensors to perform differential operations to detect the magnetic field, the symmetrical arrangement of the magnetizing bodies ensures that the multiple symmetrically arranged sensors are in the same amplification environment, preventing external magnetic interference from being amplified by the differential operations of the magnetic sensor 11.

[0020] Appendix Figure 4 The diagram shows a schematic representation of a magnetic field detection device according to a specific embodiment of the present invention. It includes a magnetic sensor 11 and magnets 42a-42c for detecting the magnetic field generated by an external magnetic source 13. In this embodiment, multiple magnets are used, with magnet 42a positioned at the center of the magnetic sensor 11; magnets 42b and 42c are symmetrically arranged with respect to the center of the magnetic sensor 11 to avoid amplifying external magnetic interference on one side. Magnets 42a-42c are all positioned on the opposite side of the external magnetic source 13 from the magnetic sensor 11, which also allows for the concentration of primary current to generate a magnetic field, increasing the Hall effect sensor output. The edge of each magnet 32 ​​is within the sensing area of ​​the magnetic sensor 11.

[0021] Appendix Figure 5The diagram shows a schematic representation of a magnetic field detection device according to a specific embodiment of the present invention. It includes a magnetic sensor 11 and magnets 52a-52c for detecting the magnetic field generated by an external magnetic source 13. In this embodiment, magnet 52a and the external magnetic source 13 are positioned on opposite sides of the magnetic sensor 11, while magnets 52b and 52c are positioned on the same side of the magnetic sensor 11. Magnets 52b and 52c are symmetrically arranged with respect to the center of the magnetic sensor 11 to avoid amplifying external magnetic interference on one side. This arrangement also allows for the concentration of primary current to generate a magnetic field, increasing the Hall effect sensor output. The edge of each magnet is within the sensing area of ​​the magnetic sensor 11.

[0022] Appendix Figure 6 The image shows a comparison of the magnetic field distribution before and after the installation of the magnetizer 12. The left side represents the original state, and the right side represents the magnetic field distribution after the installation of the magnetizer 12. The magnetic field is clearly concentrated.

[0023] The following table and Figure 7 A comparison of magnetic field strength before and after adding magnet 12 at different sizes is shown. It can be seen that the magnetic field strength is improved to varying degrees after adding magnet 12, especially when the height is greater than the length and width, the magnetization rate is particularly obvious.

[0024] Table 1 Comparison of magnetic field strength before and after setting up a magnet at different sizes

[0025]

[0026] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic field detecting device for detecting a magnetic field generated by an external magnetic source, said device comprising a magnetic sensor; characterized in that, The device further comprises a magnetic concentrator, which is disposed on the same side or on the opposite side of the magnetic sensor relative to the external magnetic source; the magnetic concentrator is made of a magnetic material, and the edge thereof is aligned with or located within the sensing area of the magnetic sensor; the magnetic concentrator is of a solid structure, and the height of the magnetic concentrator is greater than the lateral dimension of the cross section; the device comprises a plurality of magnetic concentrators, which are symmetrically disposed relative to the center of the magnetic sensor to resist external magnetic interference.

2. The magnetic field detecting device according to claim 1, characterized by Each magnetic concentrator is independently disposed on the same side or on the opposite side of the magnetic sensor relative to the external magnetic source.

3. The magnetic field detecting device according to claim 1, characterized by The cross section of the magnetic concentrator is any one of a rectangle, a polygon, and a circle.

4. The magnetic field detecting device according to claim 1, characterized by The lateral dimension is in the range of 0.2 mm to 0.5 mm.

5. The magnetic field detecting device according to claim 1, characterized by The magnetic material is selected from any one of iron, nickel, cobalt, and alloys thereof.

6. The magnetic field detecting device according to claim 1, wherein The manufacturing method of the magnetic concentrator is selected from any one of electroplating, vacuum sputtering, and molding patch.

7. The magnetic field detecting device according to claim 1, wherein The magnetic source is a primary current.

8. The magnetic field detecting device according to claim 1, characterized by The magnetic sensor is selected from any one of a horizontal Hall sensor, a vertical Hall sensor, AMR, GMR, and TMR.

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