Current Sensors

Abstract

To provide a current sensor. In the current sensor, the primary current input copper bar comprises a differential copper bar region (11) and a current shunt copper bar region (12) connected in parallel. The differential copper bar region (11) comprises a current conduction path with a U-shaped structure. The number of the current shunt copper bar regions (12) is one or more. Any current shunt copper bar region (12) is arranged with the differential copper bar region (11) in the same horizontal plane or in a different horizontal plane. The primary current input copper bar is integrally formed or formed by connecting two or more independent copper bars. A magnetic induction module fixed on a circuit board is located above the U-shaped current conduction path in the differential copper bar region (11). The output of the magnetic induction module forms the output signal of the current sensor. The current sensor has a large current measurement range, adjustable sensitivity, and strong resistance to external magnetic field interference. The input and output of the sensor are electrically isolated, and the sensor can measure AC and DC. The structure of the current sensor is simple and cost-effective.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The embodiments of the present invention relate to the technical field of electrical measurements, and in particular to current sensors. [Background technology]

[0002] Current sensors are a kind of current detection devices that can convert and output the detected current information into electrical signals or information in other desired forms that meet certain standard requirements, so as to meet the needs of information transmission, processing, storage, display, recording, and control. They are widely used in many fields, including home appliances, smart grids, electric vehicles, wind power generation, and other fields. At present, the most widely used current sensor is the magnetic current sensor, which mainly includes fluxgate current sensor, Hall current sensor, and magnetoresistance current sensor.

[0003] The fluxgate current sensor has good linearity, high accuracy, and good temperature drift performance, but requires a high permeability core, which results in large size, complex circuitry, and high cost.

[0004] Although the Hall current sensor technology is mature, it has low sensitivity, poor temperature drift characteristics, and small bandwidth, and its magnetic field sensitivity direction is perpendicular to the plane in which the Hall element is located. There are mainly two current input methods for the Hall current sensor. One is to sense the magnetic field of the current conductor to be measured through a ring-shaped iron core, which is relatively large in size, and the other is a small chip-level current sensor in which the current to be measured is directly input into a U-shaped copper conduction path and the measurement range is smaller than that of the former.

[0005] Magnetoresistance current sensors mainly include anisotropic magnetoresistor AMR current sensors, giant magnetoresistor GMR current sensors, and tunnel magnetoresistor TMR current sensors. Their magnetic field sensitivity direction is parallel to the plane where the magnetoresistance device is located, achieving high sensitivity and good linearity. However, magnetoresistance devices with high sensitivity generally have a small saturation field, and their internal magnetoresistance sensing elements tend to become magnetically saturated during large current measurement, resulting in a small current measurement range, which affects its use range. The input methods of the measured current of the magnetoresistance current sensor include the following: (1) Using a ring-shaped iron core to sense the magnetic field of the measured current conductor, which is large in size and weight. (2) Taking Allegro's ACS70331 as an example, the measured current is directly input into the single-layer U-shaped copper conduction path of the integrated GMR current sensor; (3) in patent application number 202011547895.2, the measured current is input into a copper strip with a neck recess; (4) in patent application number 201811455342.7, the measured current is input into a measured copper bar-type conductor with a rectangular or rounded rectangular cross section; in this type of input method, the single current input path is easy to exceed the linear operating range of the magnetoresistive sensing element and easily saturate the magnetoresistive sensing element, thereby limiting the current measurement range. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Application number 202011547895.2 [Patent Document 2] Application number 201811455342.7 Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENTS The embodiments of the present invention provide a current sensor to solve problems of existing current sensors, including large volume and small current measurement range. [Means for solving the problem]

[0008] Each embodiment of the present invention is a current sensor including a primary current input copper bar, a magnetic induction module, and a circuit board, The primary current input copper bar includes a primary input terminal, a primary output terminal, a differential copper bar area, and a current shunt copper bar area; The differential copper bar area and the current shunt copper bar area are electrically connected in parallel, the differential copper bar area includes a U-shaped current conduction path, the number of the current shunt copper bar areas is one or more, and either the current shunt copper bar area and the differential copper bar area are located in the same horizontal plane or in different horizontal planes; The number of the primary input terminals is one or more, and the number of the primary output terminals is one or more, and either the primary input terminal or the primary output terminal is electrically connected to the differential copper bar area or the current shunt copper bar area; The primary current input copper bar is formed in one of the following two ways: (1) integrally formed; and (2) formed by connecting two or more independent copper bars, and the independent copper bars include some or all of the primary input terminal, the primary output terminal, the differential copper bar area, and the copper bar area for the current shunt; The magnetic induction module is fixed on the circuit board and located above the U-shaped current conduction path in the differential copper bar area, and the output of the magnetic induction module provides a current sensor, forming an output signal of the current sensor.

[0009] The current sensor provided by each embodiment of the present invention has a large current measurement range, electrically isolates the input and output, can measure AC and DC currents, has adjustable sensitivity, and has strong resistance to external magnetic field interference. Compared with the prior art, the current measurement range is adjusted by shunting the U-shaped current conduction path in parallel, and therefore the current input range can be adjusted by controlling the structure, amount, and plane of the copper bar area for current shunting, thereby realizing large current measurement without iron core and reducing the volume and weight; furthermore, the design of the current sensor is simplified by adopting integrated processing, the structure is simple, and the manufacturing cost is reduced; it is suitable for the magnetic induction unit whose magnetic field sensitivity direction is perpendicular or parallel to the plane where the magnetic induction module is located, and expands the measurement range of the magnetoresistance device with high sensitivity and small saturation field, and has the characteristics of electrical isolation of input and output, ability to measure AC and DC currents, adjustable sensitivity, and strong resistance to external magnetic field interference.

[0010] In order to more clearly show the technical solutions in each embodiment of the present invention or the prior art, the accompanying drawings necessary for use in each embodiment or the prior art are briefly introduced below. Obviously, the accompanying drawings described below are some specific embodiments of the present invention, but for those skilled in the art, the basic concepts of the device structure, driving method and manufacturing method disclosed and promoted by various embodiments of the present invention can be expanded and extended to other structures and drawings, which undoubtedly all fall within the scope of the claims of the present invention. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram of an existing U-shaped copper conduction path. [Diagram 2] FIG. 2 is a schematic diagram of the simulation calculation results in which the x-component of the magnetic field generated in FIG. 1 varies along the x-axis. [Diagram 3] FIG. 2 is a schematic diagram of the results of a simulation calculation in which the z-component of the magnetic field generated in FIG. 1 varies along the x-axis. [Figure 4] FIG. 2 is a schematic diagram of a primary side current input copper bar according to an embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic diagram of the simulation calculation results in which the x-component of the magnetic field generated in FIG. 4 varies along the x-axis. [Figure 6] FIG. 5 is a schematic diagram of the simulation calculation results in which the z-component of the magnetic field generated in FIG. 4 varies along the x-axis. [Figure 7] FIG. 13 is a schematic diagram of another primary side current input copper bar according to an embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram of a simulation calculation result in which the x-component of the magnetic field generated in FIG. 7 varies along the x-axis. [Figure 9] FIG. 13 is a schematic diagram of yet another primary side current input copper bar according to an embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram of a simulation calculation result in which the x-component of the magnetic field generated in FIG. 9 varies along the x-axis. [Figure 11] FIG. 13 is a schematic diagram of yet another primary side current input copper bar according to an embodiment of the present invention. [Figure 12] FIG. 12 is a schematic diagram of the simulation calculation results in which the x-component of the magnetic field generated in FIG. 11 varies along the x-axis. [Figure 13] A schematic diagram showing the principle of the single-bridge differential half-bridge structure of the magnetic induction module. [Figure 14] A schematic diagram showing the principle of the single-bridge differential full-bridge structure of the magnetic induction module. [Figure 15] FIG. 1 is a schematic diagram showing the principle of the double push-pull half-bridge differential structure of the magnetic induction module. [Figure 16] A schematic diagram showing the principle of the double push-pull full-bridge differential structure of the magnetic induction module. [Figure 17] 1 is a cross-sectional view of a current sensor according to an embodiment of the present invention. [Figure 18] FIG. 2 is a cross-sectional view of another current sensor according to an embodiment of the present invention. [Figure 19]13 is a cross-sectional view of yet another current sensor in accordance with an embodiment of the present invention; [Figure 20] FIG. 20 is a schematic plan view of the current sensor shown in FIG. [Figure 21] 13 is a cross-sectional view of yet another current sensor in accordance with an embodiment of the present invention; [Figure 22] 13 is a cross-sectional view of yet another current sensor in accordance with an embodiment of the present invention; [Diagram 23] FIG. 23 is a schematic plan view of the current sensor shown in FIG. 22. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are clearly and completely described below through implementation forms, with reference to the accompanying drawings in each embodiment of the present invention. It is clear that each embodiment described is not all the embodiments of the present invention, but some embodiments of the present invention. Based on the basic concept disclosed and promoted by each embodiment of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0013] One embodiment of the present invention is a current sensor including a primary current input copper bar, a magnetic induction module, a circuit board, and a primary current input copper bar, wherein the primary current input copper bar includes a primary input terminal, a primary output terminal, a differential copper bar area, and a current shunt copper bar area, the differential copper bar area and the current shunt copper bar area are electrically connected in parallel, the differential copper bar area includes a U-shaped current conduction path, the number of the current shunt copper bar areas is one or more, any current shunt copper bar area and the differential copper bus area are located in the same horizontal plane or in different horizontal planes, the number of the primary input terminals is one or more, the number of the primary output terminals is one or more, the primary input terminals are one or more, the number of the primary output terminals is one or more, the primary input terminals are one or more, the primary output terminals are ... and any one of the primary output terminals is electrically connected to the differential copper bar area or electrically connected to the copper bar area for current shunt, the primary current input copper bar is formed by one of the following two situations, namely (1) being integrally formed, or (2) being formed by connecting two or more independent copper bars, the independent copper bars include some or all of the primary input terminals, the primary output terminals, the differential copper bar area, and the copper bar area for current shunt, the magnetic induction module is fixed on the circuit board, the magnetic induction module is located above the U-shaped current conduction path in the differential copper bar area, and the output of the magnetic induction module forms the output signal of the current sensor, providing a current sensor.

[0014] As mentioned above, the current sensor converts the measured current into the input magnetic field of the magnetic induction module through the primary current input copper bar, realizing large current measurement without the need for iron cores, reducing volume and weight, having a simple structure and low processing costs, and expanding the measurement range of the magnetoresistance device with high sensitivity and small saturation field. It has the characteristics of input and output electrical isolation, ability to measure AC current and DC current, adjustable sensitivity, and strong resistance to external magnetic field interference.

[0015] Optionally, the magnetic induction module adopts one of the following three cases: (1) The magnetic induction module includes at least a first magnetic induction unit and a second magnetic induction unit therein, the first magnetic induction unit and the second magnetic induction unit are respectively located above two current conduction paths having a parallel positional relationship in a U-shaped current conduction path, the first magnetic induction unit and the second magnetic induction unit sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane where the magnetic induction module is located; (2) the magnetic induction module includes at least a third magnetic induction unit therein, the vertical projection position of the third magnetic induction unit is located inside the U-shaped enclosed area of ​​the U-shaped current conduction path, the third magnetic induction unit directly senses the magnetic field generated by the primary current input copper bar and generates a voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is perpendicular to the plane in which the magnetic induction module is located; (3) The magnetic induction module includes at least a third magnetic induction unit and a fourth magnetic induction unit therein, the vertical projection position of the fourth magnetic induction unit is located outside the U-shaped enclosed area of ​​the U-shaped current conduction path, the third magnetic induction unit and the fourth magnetic induction unit sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is perpendicular to the plane in which the magnetic induction module is located.

[0016] Optionally, the first magnetic induction unit and the second magnetic induction unit each include one or more magnetoresistive bridge arms, each magnetoresistive bridge arm being comprised of one or more magnetoresistive sensing elements connected in series and parallel; In the first magnetic induction unit and the second magnetic induction unit, a bridge structure adopted by any magnetic induction unit is one of a differential half-bridge structure, a differential full-bridge structure, a double push-pull half-bridge differential structure, and a double push-pull full-bridge differential structure; (1) the differential half-bridge structure is a single-bridge, and the first magnetic induction unit and the second magnetic induction unit together constitute the same single-bridge differential half-bridge structure to form an output signal of the differential half-bridge structure; (2) The differential full-bridge structure is a single bridge, and the first magnetic induction unit and the second magnetic induction unit together constitute the same single-bridge differential full-bridge structure to form an output signal of the differential full-bridge structure; (3) In the double push-pull half-bridge differential structure, the first magnetic induction unit and the second magnetic induction unit both adopt a push-pull half-bridge structure, each of which forms a voltage output signal, and the voltage output signals of the two push-pull half-bridge structures differentially form an output signal of the double push-pull half-bridge differential structure; (4) In the double push-pull full-bridge differential structure, the first magnetic induction unit and the second magnetic induction unit both adopt a push-pull full-bridge structure, each forming a voltage output signal, and the voltage output signals of the two push-pull full-bridge structures differentially form an output signal of the double push-pull full-bridge differential structure.

[0017] Optionally, the primary current input copper bar is electrically isolated from the magnetic induction module and the circuit board, respectively.

[0018] Optionally, the magnetic induction module also includes a signal conditioning circuit, the signal conditioning circuit employing one of an open-loop signal conditioning circuit and a closed-loop signal conditioning circuit.

[0019] The above is the main idea of ​​the present invention. The current sensor provided by the present embodiment of the present invention will be briefly described below in comparison with the prior art, and in combination with the accompanying drawings and some simulation results.

[0020] The following is a brief description of different designs of primary current input copper bars. In this embodiment of the present invention, the primary current input copper bar may also be called the primary current conductor or copper primary conduction path, which mainly serves to introduce the measured current to the current sensor. The U-shaped structure in this embodiment of the present invention refers to a structure in which the current conduction path has a current anti-parallel position relationship, and thus includes, but is not limited to, similar shapes such as "Ω" type, "n" type, etc., using acute, right, obtuse, or round angles as turning points.

[0021] Referring to FIG. 1, FIG. 1 is a schematic diagram of an existing U-shaped copper conductive path. As shown in FIG. 1, the existing U-shaped copper conductive path is a single-layer U-shaped copper conductive path, i.e., a U-shaped copper bar. The horizontal rightward direction in the plane of the U-shaped copper bar is the positive direction of the x-axis, the vertical upward direction in the plane of the U-shaped copper bar is the positive direction of the y-axis, and the direction perpendicular to the plane of the U-shaped copper bar is the z-axis direction, and the current to be measured is directly input into the single-layer U-shaped copper conductive path. The two magnetic induction units 211 and 212 are located in the same plane and are also located above the U-shaped copper bar, i.e., the vertical projection of the U-shaped copper bar along the z-direction covers the two magnetic induction units 211 and 212.

[0022] Suppose the measured current is 50A, the measured current is input into the U-shaped copper bar. Through finite element simulation calculation and analysis, the measured current generates a magnetic field in the plane of the magnetic induction unit above the U-shaped copper bar.

[0023] Reference is made to Fig. 2, which is a schematic diagram showing a simulation calculation result in which the x-component of the magnetic field varies along the x-axis. Reference is made to Fig. 3, which is a schematic diagram showing a simulation calculation result in which the z-component of the magnetic field varies along the x-axis. From Fig. 2 and Fig. 3, it can be seen that the x-component of the magnetic field generated by the measured current varies within a range of -9mT to +9mT along the x-axis, and the z-component of the magnetic field generated by the measured current varies within a range of -15mT to +2.5mT along the x-axis.

[0024] Referring to FIG. 4, FIG. 4 is a schematic diagram of a primary current input copper bar according to an embodiment of the present invention. In this embodiment, the primary current input copper bar includes a differential copper bar area 11, which has a U-shaped current conduction path as shown in FIG. 1, and the primary current input copper bar also includes a current shunt copper bar area 12, and the differential copper bar area 11 and the current shunt copper bar area 12 are located in the same plane and electrically connected in parallel. The primary current input copper bar further includes a primary input terminal 13 and a primary output terminal 14. In other embodiments, the number of current shunt copper bar areas can be two or more, and the current shunt copper bar area and the differential copper bar area can be located on the same horizontal plane or on different horizontal planes.

[0025] 4, optionally, the magnetic induction module includes at least a third magnetic induction unit 213 therein, the vertical projection position of the third magnetic induction unit 213 is located inside the U-shaped enclosed area of ​​the U-shaped current conducting path 11, the third magnetic induction unit 213 directly senses the magnetic field generated by the primary current input copper bar and generates a voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is perpendicular to the plane where the magnetic induction module is located. The third magnetic induction unit 213 and the U-shaped current conducting path 11 are located on the same plane.

[0026] Assuming that the measured current is 50A, which is the same as FIG. 1, the measured current is input to the primary current input copper bar. Through finite element simulation calculation and analysis, the measured current generates a magnetic field in the plane of the magnetic induction unit above the primary current input copper bar. Reference is made to FIG. 5, which is a schematic diagram showing the simulation calculation result of the x-component of the magnetic field generated in FIG. 4 varying along the x-axis. Reference is made to FIG. 6, which is a schematic diagram showing the simulation calculation result of the z-component of the magnetic field generated in FIG. 4 varying along the x-axis. It can be seen from FIG. 5 and FIG. 6 that the magnitude of the magnetic field generated by the measured current is significantly reduced. The range of the x-component of the magnetic field generated by the measured current varying along the x-axis is reduced from -0.75mT to +0.75mT, and the range of the z-component of the magnetic field generated by the measured current varying along the x-axis is reduced from -0.95mT to +0.45mT.

[0027] Compared with FIG. 1, for a magnetic induction unit with the same magnetic field measurement range, the structure shown in FIG. 4 can achieve an increase in the current measurement range. From the simulation result of the z component of the magnetic field in FIG. 6, it can be seen that the x component of the magnetic field and the z component of the magnetic field generated by the primary current input copper bar at different positions along the x-axis direction in this embodiment have obvious changes. Therefore, the current can be detected by placing the magnetic induction unit whose sensitivity direction is perpendicular to the z direction at the position where the x coordinate is zero and using non-differential measurement, and in other embodiments, the current can also be detected by placing the magnetic induction unit whose sensitivity direction is along the in-plane x-axis in different positions and using differential measurement.

[0028] Referring to Fig. 7, a schematic diagram of another primary current input copper bar provided in one embodiment of the present invention is shown, and referring to Fig. 8, a schematic diagram of a simulation calculation result in which the x-component of the magnetic field generated in Fig. 7 varies along the x-axis is shown. In this embodiment, the differential copper bar area 11 and the U-shaped current shunt copper bar area 12 are located in the same plane and are electrically connected in parallel.

[0029] 7, optionally, the magnetic induction module includes at least a first magnetic induction unit 211 and a second magnetic induction unit 212 therein, the first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above the two current conduction paths having a parallel positional relationship in the U-shaped current conduction path 11, the first magnetic induction unit 211 and the second magnetic induction unit 212 sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane where the magnetic induction module is located. The first magnetic induction unit 211 and the second magnetic induction unit 212 are located on the same plane.

[0030] Under the same current conditions as the above embodiment, the magnitude of the magnetic field generated by the measured current shown in Figure 8 is significantly reduced compared to Figure 2. Specifically, the x-component of the magnetic field generated by the measured current varies within the range of -4.5mT to +4.5mT along the x-axis.

[0031] Referring to Fig. 9, a schematic diagram of yet another primary current input copper bar provided in an embodiment of the present invention is shown, and referring to Fig. 10, a schematic diagram of a simulation calculation result in which the x-component of the magnetic field generated in Fig. 9 varies along the x-axis is shown. In this embodiment, the differential copper bar region 11 and the U-shaped current shunt copper bar region 12 are located in different horizontal planes and are electrically connected in parallel.

[0032] 9, optionally, the magnetic induction module includes at least a first magnetic induction unit 211 and a second magnetic induction unit 212 therein, the first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above the two current conducting paths having a parallel positional relationship in the U-shaped current conducting path 11, the first magnetic induction unit 211 and the second magnetic induction unit 212 sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane where the magnetic induction module is located. The first magnetic induction unit 211 and the second magnetic induction unit 212 are located on the same plane.

[0033] Under the same current conditions as the above embodiment, the magnitude of the magnetic field generated by the measured current shown in Figure 10 is significantly reduced compared to Figure 2. Specifically, the x-component of the magnetic field generated by the measured current varies within the range of -3mT to +3mT along the x-axis.

[0034] Referring to Fig. 11, a schematic diagram of yet another primary current input copper bar provided in an embodiment of the present invention is shown, and referring to Fig. 12, a schematic diagram of a simulation calculation result in which the x-component of the magnetic field generated in Fig. 11 changes along the x-axis is shown. As shown in Fig. 11, optionally, two ends of the U-shaped opening of the U-shaped current conducting path are electrically connected. The differential copper bar region 11 and the copper bar region 12 for U-shaped current shunt can be located in the same horizontal plane or in different horizontal planes, and the two are electrically connected in parallel, and then the two ends of the U-shaped opening of the U-shaped current conducting path in the differential copper bar region 11 are connected to form a new current conducting path 111.

[0035] 11, optionally, the magnetic induction module includes at least a first magnetic induction unit 211 and a second magnetic induction unit 212 therein, the first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above the two current conducting paths having a parallel positional relationship in the U-shaped current conducting path 11, the first magnetic induction unit 211 and the second magnetic induction unit 212 sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane where the magnetic induction module is located. The first magnetic induction unit 211 and the second magnetic induction unit 212 are located on the same plane.

[0036] Under the same current conditions as the above embodiment, the magnitude of the magnetic field generated by the measured current shown in Figure 12 is significantly reduced compared to Figure 2. Specifically, the x-component of the magnetic field generated by the measured current varies within the range of -1.4mT to +1.4mT along the x-axis.

[0037] The above embodiments provide that the differential copper bar area in the primary current input copper bar is matched with differently designed current shunt copper bar areas to form various different current paths. Analysis shows that the combination of the differential copper bar area and the differently designed current shunt copper bar area can have a significant effect on the x component of the magnetic field. Therefore, by controlling the structure, amount, plane and thickness of the current shunt copper bar area, the input range of the measured current can be controlled.

[0038] In addition, it can be seen from the above embodiments that the x-components of the magnetic fields generated by the primary current input copper bars of different designs in each embodiment of the present invention in the central region of the cross section where the magnetic induction unit is located vary approximately linearly along the x-axis, with obvious differences at different positions, and the magnetic field directions on the two sides of the center are opposite, resulting in odd symmetrical characteristics. Therefore, the current can be detected by differential measurement by arranging the magnetic sensing units with sensitivity directions along the in-plane x-axis at different positions.

[0039] The following is a brief description of the magnetic induction modules with different bridge structure designs.

[0040] Optionally, the magnetic induction module includes at least a first magnetic induction unit and a second magnetic induction unit therein, the first magnetic induction unit and the second magnetic induction unit are respectively located above two current conduction paths having a parallel positional relationship in the U-shaped current conduction path, the first magnetic induction unit and the second magnetic induction unit sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane in which the magnetic induction module is located.

[0041] From the example of the primary current input copper bar, it can be seen that when the measured current is input to the primary current input copper bar, the primary current input copper bar can generate a differential mode magnetic field at the positions of the first magnetic induction unit 211 and the second magnetic induction unit 212, and the magnetic field x components of the differential mode magnetic field have obvious differences and are in opposite directions on the two sides of the center of the U-shaped differential copper bar area. Without loss of generality, the following assumptions are used for explanation. Assuming that the horizontal right direction is the positive direction of the magnetic field, then the differential mode magnetic field is directed to the right at the position of the first magnetic induction unit 211 and directed to the left at the position of the second magnetic induction unit 212.

[0042] Referring to FIG. 13, FIG. 13 is a schematic diagram showing the principle of a single-bridge differential half-bridge structure. In the magnetic induction module, the first magnetic induction unit 211 and the second magnetic induction unit 212 have the same sensitivity direction, both facing rightward, and the two magnetic induction units together form a single-bridge differential half-bridge structure. The first magnetic induction unit 211 includes a magnetic resistance bridge arm 211a, and the second magnetic induction unit 212 includes a magnetic resistance bridge arm 212a. The two magnetic resistance bridge arms form a differential half-bridge structure, and the output Vout is the output signal of the single-bridge differential half-bridge structure.

[0043] When the current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. When the differential mode magnetic field is sensed under the aforementioned conditions, the resistance value of the magnetic resistance bridge arm 211a decreases, and the resistance value of the magnetic resistance bridge arm 212a increases. According to Biot-Savart law, the Vout output changes linearly with respect to the magnitude of the measured current. Since the sensitivity direction of the first magnetic induction unit 211 and the sensitivity direction of the second magnetic induction unit 212 in the differential half-bridge structure are the same, for an external uniform magnetic field (i.e., common mode magnetic field), the resistance values ​​of the two magnetic resistance bridge arms 211a and 212a increase or decrease simultaneously. At this time, the Vout output has no response, and therefore has good resistance to common mode magnetic field interference.

[0044] Referring to FIG. 14, FIG. 14 is a schematic diagram showing the principle of a single-bridge differential full-bridge structure. In the magnetic induction module, the first magnetic induction unit 211 and the second magnetic induction unit 212 together form a single-bridge differential full-bridge structure. Among them, the first magnetic induction unit 211 includes two magnetoresistance bridge arms 211b1 and 211b2, and the second magnetic induction unit 212 includes two magnetoresistance bridge arms 212b1 and 212b2. The sensitivity directions of the four magnetoresistance bridge arms 211b1, 211b2, 212b1, and 212b2 are all consistent and point to the right, and together they form a differential full-bridge structure. The output terminals V1 and V2 of the differential full-bridge structure form the Vout output signal of the single-bridge differential full-bridge structure.

[0045] When the current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. When the differential mode magnetic field is sensed under the above conditions, the resistance values ​​of the magnetoresistance bridge arms 211b1 and 211b2 decrease, and the resistance values ​​of the magnetoresistance bridge arms 212b1 and 212b2 increase. As a result, the output voltage value V1 decreases, and the output voltage value V2 increases. The corresponding Vout output signal of the single-bridge differential full-bridge structure changes with respect to the differential mode magnetic field. Similarly, since the sensitivity directions of the four magnetoresistance bridge arms 211b1, 211b2, 212b1, and 212b2 are consistent, for an external uniform magnetic field (i.e., a common mode magnetic field), the resistance values ​​of the four magnetoresistance bridge arms 211b1, 211b2, 212b1, and 212b2 increase or decrease simultaneously. At this time, the Vout output has no response and therefore has good immunity to common-mode magnetic field interference.

[0046] Referring to FIG. 15, FIG. 15 is a schematic diagram showing the principle of a double push-pull half-bridge differential structure. In the magnetic induction module, the first magnetic induction unit 211 forms a push-pull half-bridge structure, the second magnetic induction unit 212 forms a push-pull half-bridge structure, and the first magnetic induction unit 211 and the second magnetic induction unit 212 together form a double push-pull half-bridge differential structure. The first magnetic induction unit 211 and the second magnetic induction unit 212 have the same sensitivity direction, as well as approximately the same structure and characteristics. Specifically, the first magnetic induction unit 211 includes two magnetic resistance bridge arms 211c1 and 211c2, forming a push-pull half-bridge structure with an output V1c, and the second magnetic induction unit 212 includes two magnetic resistance bridge arms 212c1 and 212c2, forming a push-pull half-bridge structure with an output V2c. The differential signals at the output terminals V1c and V2c of the two push-pull half-bridge structures form the Vout output signal of the double push-pull half-bridge differential structure.

[0047] The sensitivity direction of the upper magnetoresistance bridge arms 211c1 and 212c1 of the two magnetic induction units is to the left, and the sensitivity direction of the lower magnetoresistance bridge arms 211c2 and 212c2 is to the right. When the current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. When the differential mode magnetic field is sensed under the above conditions, the resistance value of the magnetoresistance bridge arms 211c2 and 212c1 decreases, and the resistance value of the magnetoresistance bridge arms 211c1 and 212c2 increases. As a result, the output voltage value V1c decreases and the output voltage value V2c increases. The corresponding Vout output signal of the double push-pull half-bridge differential structure changes with respect to the differential mode magnetic field. Similarly, the double push-pull half-bridge differential structure has good resistance to common mode magnetic field interference.

[0048] Referring to FIG. 16, FIG. 16 is a schematic diagram showing the principle of a double push-pull half-bridge differential structure. In the magnetic induction module, the first magnetic induction unit 211 forms a push-pull full-bridge structure, and the second magnetic induction unit 212 forms a push-pull full-bridge structure, and the first magnetic induction unit 211 and the second magnetic induction unit 212 together form a double push-pull full-bridge differential structure. The first magnetic induction unit 211 and the second magnetic induction unit 212 have the same sensitivity direction, as well as approximately the same structure and characteristics. Specifically, the first magnetic induction unit 211 includes four magnetic resistance bridge arms 211d1, 211d2, 211d3, and 211d4, forming a push-pull full-bridge structure. The difference between the two output terminals V1d1 and V1d2 of the push-pull full-bridge structure constitutes the output V1d of the first magnetic induction unit 211. The second magnetic induction unit 212 includes four magnetoresistance bridge arms 212d1, 212d2, 212d3, and 212d4, which form a push-pull full-bridge structure. The difference between the two output terminals V2d1 and V2d2 of the push-pull full-bridge structure constitutes the output V2d of the second magnetic induction unit 212. The differential signals of the output terminals V1d and V2d of the two push-pull full-bridge structures form the Vout output signal of the double push-pull full-bridge differential structure.

[0049] The sensitivity direction of the four magnetoresistance bridge arms 211d2, 211d3, 212d2, and 212d3 is to the left, and the sensitivity direction of the four magnetoresistance bridge arms 211d1, 211d4, 212d1, and 212d4 is to the right. When the current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. When the differential mode magnetic field is sensed under the above conditions, the resistance values ​​of the four magnetoresistance bridge arms 211d1, 211d4, 212d2, and 212d3 decrease, and the resistance values ​​of the four magnetoresistance bridge arms 211d2, 211d3, 212d1, and 212d4 increase, so that the output voltage values ​​V1d2 and V2d1 both decrease, and the output voltage values ​​V1d1 and V2d2 both increase. The difference V1d between V1d1 and V1d2 is positive, and the difference V2d between V2d1 and V2d2 is negative, so the Vout output signal formed by the difference between the outputs V1d and V2d of the two push-pull full-bridge structures is numbered with the differential mode magnetic field. Similarly, the double push-pull full-bridge differential structure has good immunity to common mode magnetic field interference.

[0050] In addition to the above four typical bridge structures, it can be understood that the structure of the magnetic induction module can also be modified according to specific application circumstances, such as the differential output of half-bridge structure and full-bridge structure, the sensitivity direction setting of each bridge arm, the setting of two or more magnetic induction units, etc., based on the same principle, thereby forming a magnetic induction module with other bridge structures. Optionally, each of the above magnetic resistance bridge arms is formed by connecting one or more magnetic resistance sensing elements in series and parallel.

[0051] The following is a brief description of the closed-loop negative feedback signal conditioning circuit in the magnetic induction module. Optionally, the magnetic induction module also includes a signal conditioning circuit, which adopts one of an open-loop signal conditioning circuit and a closed-loop signal conditioning circuit.

[0052] Please refer to FIG. 17, which is a schematic diagram of a current sensor provided in an embodiment of the present invention. Please refer to FIG. 18, which is a schematic diagram of another current sensor provided in an embodiment of the present invention. Please refer to FIG. 19, which is a schematic diagram of yet another current sensor provided in an embodiment of the present invention. Optionally, the magnetic induction module 2 includes a first magnetic induction unit 211 and a second magnetic induction unit 212. The closed-loop signal conditioning circuit uses a magnetic field feedback coil 22. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22, the first magnetic induction unit 211, and the second magnetic induction unit 212 constitute a closed-loop magnetic field feedback. The differential voltage signal of the bridge structure in the above magnetic induction module is amplified, and then generates a feedback magnetic field by driving the magnetic field feedback coil 22. The feedback magnetic field inversely offsets the magnetic field difference (i.e., the differential mode magnetic field) generated by the primary current input copper bar 1 at the positions of the first magnetic induction unit 211 and the second magnetic induction unit 212. When the dynamic balance of the magnetic field is realized, the first magnetic induction unit 211 and the second magnetic induction unit 212 operate under the same common mode magnetic field condition, and the feedback current of the magnetic field feedback coil 22 is sampled via the sampling resistor to form the output of the magnetic induction module 2. The primary current input copper bar further includes a current shunt copper bar area 12, a primary input terminal 13, and a primary output terminal 14.

[0053] Optionally, the magnetic field feedback coil 22 is integrated into the closed-loop signal conditioning circuit, or into the circuit board 3, or into the magnetic induction unit, or into the ASIC dedicated integrated circuit, or into the magnetic induction module 2. When the magnetic field feedback coil 22 is integrated into different positions, the working principle is the same, and the operation of the closed-loop magnetic field negative feedback is not affected.

[0054] 17, optionally, the magnetic field feedback coil 22 is integrated inside the magnetic induction module 2, and the plane where the magnetic field feedback coil 22 is located is parallel to the plane where the first magnetic induction unit 211 and the second magnetic induction unit 212 are located. The magnetic field feedback coil 22 is symmetrically distributed on both sides of the center line of the U-shaped current conduction path of the differential copper bar region 11 in the primary current input copper bar 1 in the cross section shown in FIG. 17, furthermore, the current direction of the magnetic field feedback coil 22 on one side of the center line is outward perpendicular to the paper plane, and the current direction of the magnetic field feedback coil 22 on the other side of the center line is inward perpendicular to the paper plane.

[0055] Take an example where the magnetic field direction of the measured current is rightward at the position of the first magnetic induction unit 211 and leftward at the position of the second magnetic induction unit 212, in order to inversely offset the differential mode magnetic field generated by the measured current, the current direction of the conductor horizontally arranged under the first magnetic induction unit 211 of the magnetic field feedback coil 22 is outward perpendicular to the paper, and the current direction of the conductor horizontally arranged under the second magnetic induction unit 212 of the magnetic field feedback coil 22 is inward perpendicular to the paper. Thus, the magnetic field feedback coil 22 generates a horizontally leftward feedback magnetic field at the first magnetic induction unit 211, and the magnetic field feedback coil 22 generates a horizontally rightward feedback magnetic field at the second magnetic induction unit 212 to inversely offset the differential mode magnetic field generated by the measured current, thereby realizing dynamic equilibrium of the magnetic field.

[0056] As shown in Fig. 18, optionally, the magnetic field feedback coil 22 is integrated inside the circuit board 3. As shown in Fig. 19, optional magnetic field feedback coil 22 is integrated inside the first magnetic induction unit 211 and the second magnetic induction unit 212. In other embodiments, the magnetic field feedback coil can be optionally integrated in other positions, not limited to the positions shown in the above figures. Although the distribution or connection of the magnetic field feedback coil is slightly different, the feedback magnetic field generated by the magnetic field feedback coil is always used to offset the differential mode magnetic field generated by the measured current, and finally, the detection of the measured current is realized.

[0057] Based on the above structure, the overall structure of the current sensor provided by this embodiment of the present invention is briefly summarized.

[0058] One embodiment of the present invention provides a first current sensor as shown in FIG. 7, and its cross-sectional view is shown in FIG. 17, the current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4, the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, a copper bar area 12 for current shunt, a primary input terminal 13, and a primary output terminal 14. The primary current input copper bar 1 can be an integrally formed copper bar, that is, the differential copper bar area 11, the copper bar area 12 for current shunt, the primary input terminal 13, and the primary output terminal 14 are located in the same horizontal plane. Optionally, the differential copper bar area 11 and the copper bar area 12 for current shunt are connected in parallel, and the connection points at the two ends are the primary input terminal 13 and the primary output terminal 14, respectively. After the current to be measured flows into the primary input terminal 13, it is shunted through the differential copper bar area 11 and the current shunt copper bar area 12 and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, fix and support the various components in the current sensor. The magnetic induction module 2 is fixed on the circuit board 3, and both are electrically insulated from the primary current input copper bar 1.

[0059] The magnetic induction module 2 includes a first magnetic induction unit 211 and a second magnetic induction unit 212, the first magnetic induction unit 211 and the second magnetic induction unit 212 are located in the same horizontal plane, and both have sensitivity directions horizontally facing rightward. The first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two current conduction paths having a parallel positional relationship in the U-shaped current conduction path of the differential copper bar region 11, and optionally, the current direction of the current conduction path below the first magnetic induction unit 211 is inward perpendicular to the paper plane, and the current direction of the current conduction path below the second magnetic induction unit 212 is outward perpendicular to the paper plane.

[0060] The magnetoresistance sensing elements used by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both tunnel magnetoresistors TMR. As shown in FIG. 13, the two magnetic induction units each include a magnetoresistance bridge arm, and the first magnetic induction unit 211 and the second magnetic induction unit 212 together constitute the same single-bridge differential half-bridge structure, which senses the differential mode magnetic field generated by the primary current input copper bar 1 in a differential manner and generates a differential voltage signal. The magnetic induction module 2 adopts a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated in the magnetic induction module 2, the first magnetic induction unit 211, and the second magnetic induction unit 212 together constitute a closed-loop magnetic field feedback. The output of the magnetic induction module 2 forms the output signal of the current sensor.

[0061] An embodiment of the present invention provides a second current sensor as shown in FIG. 9, and its cross-sectional view is shown in FIG. 18, in which the current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4, and the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, a copper bar area 12 for current shunt, a primary input terminal 13, and a primary output terminal 14.

[0062] Optionally, the current shunt copper bar area 12 is located below or above the plane where the differential copper bar area 11 is located. The differential copper bar area 11 and the current shunt copper bar area 12 are two independent copper bars connected in parallel, and the connection points at the two ends are the primary input terminal 13 and the primary output terminal 14, respectively. Except for the connection points at the two ends, the differential copper bar area 11 and the current shunt copper bar area 12 located in different planes are insulated from each other. After the current to be measured flows into the primary input terminal 13, it is shunted through the differential copper bar area 11 and the current shunt copper bar area 12 and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, fix and support various components in the current sensor. The magnetic induction module 2 is fixed on the circuit board 3, and both are electrically insulated from the primary current input copper bar 1.

[0063] The magnetic induction module 2 includes a first magnetic induction unit 211 and a second magnetic induction unit 212, the first magnetic induction unit 211 and the second magnetic induction unit 212 are located in the same horizontal plane, and both have sensitivity directions horizontally facing rightward. The first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two current conduction paths having a parallel positional relationship in the U-shaped current conduction path of the differential copper bar region 11, and optionally, the current direction of the current conduction path below the first magnetic induction unit 211 is inward perpendicular to the paper plane, and the current direction of the current conduction path below the second magnetic induction unit 212 is outward perpendicular to the paper plane.

[0064] The magnetoresistance sensing elements used by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both giant magnetoresistors GMR. As shown in FIG. 14, the two magnetic induction units each include two magnetoresistance bridge arms, and the first magnetic induction unit 211 and the second magnetic induction unit 212 together configure the same single-bridge differential full-bridge structure, which senses the differential mode magnetic field generated by the primary current input copper bar 1 in a differential manner and generates a differential voltage signal. The magnetic induction module 2 adopts a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated in the magnetic circuit board 3, the first magnetic induction unit 211, and the second magnetic induction unit 212 together configure a closed-loop magnetic field feedback. The output of the magnetic induction module 2 forms the output signal of the current sensor.

[0065] An embodiment of the present invention provides a third current sensor as shown in FIG. 11, and its cross-sectional view is shown in FIG. 17. The current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4. The primary current input copper bar 1 comprises a differential copper bar area 11 having a U-shaped current conduction path, a current shunt copper bar area 12, a primary input terminal 13, and a primary output terminal 14. Optionally, the primary current input copper bar 1 is an integrally formed copper bar, i.e., the differential copper bar area 11, the current shunt copper bar area 12, the primary input terminal 13, and the primary output terminal 14 are located in the same horizontal plane. The main difference between Figure 11 and Figure 7 is that the differential copper bar region 11 in the current sensor shown in Figure 11 connects the two ends of the U-shaped opening of the U-shaped current conducting path through another third current conducting path 111, and a part of the measured current passing through the differential copper bar region 11 is shunted again, further reducing the magnetic field generated by the measured current in the magnetic induction module 2.

[0066] As shown in Figure 15, the first magnetic induction unit 211 adopts a push-pull half-bridge structure to form a voltage output signal, the second magnetic induction unit 212 adopts a push-pull half-bridge structure to form a voltage output signal, the two push-pull half-bridge structures form a double push-pull half-bridge differential structure, and the voltage output of the two push-pull half-bridge structures forms a differential voltage signal. The magnetic induction module 2 adopts a closed-loop signal conditioning circuit matched with the first current sensor to form a closed-loop magnetic field feedback. The output of the magnetic induction module 2 forms the output signal of the current sensor.

[0067] One embodiment of the present invention provides a fourth current sensor as shown in Fig. 19, and its plan view is shown in Fig. 20, the current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4, as shown in Fig. 20, and the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, two current shunt copper bar areas 121 and 122, a primary input terminal 13, and a primary output terminal 14. Optionally, the primary current input copper bar 1 is an integrally formed copper bar, i.e., the differential copper bar area 11, the two current shunt copper bar areas 121 and 122, the primary input terminal 13, and the primary output terminal 14 are located in the same horizontal plane. The differential copper bar area 11 and the current shunt copper bar areas 121&122 are connected in parallel, and the connection points at the two ends are the primary input terminal 13 and the primary output terminal 14, respectively. After the current to be measured flows into the primary input terminal 13, it is shunted through the differential copper bar region 11 and the current shunt copper bar regions 121 and 122 and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, secure and support the various components in the current sensor.

[0068] The magnetic induction module 2 is fixed on the circuit board 3, and both are electrically insulated from the primary current input copper bar 1. The magnetic induction module 2 includes a first magnetic induction unit 211 and a second magnetic induction unit 212, which are located in the same horizontal plane and have a sensitivity direction facing horizontally to the right. As shown in FIG. 19, the first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two current conduction paths having a parallel positional relationship in the U-shaped structure of the differential copper bar region 11, and the current direction of the current conduction path below the first magnetic induction unit 211 is inward perpendicular to the paper plane, and the current direction of the current conduction path below the second magnetic induction unit 212 is outward perpendicular to the paper plane.

[0069] The magnetoresistance sensing elements adopted by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both tunnel magnetoresistors TMR. Each magnetic induction unit includes a push-pull full-bridge structure composed of four magnetoresistance bridge arms. As shown in FIG. 16, the first magnetic induction unit 211 adopts a push-pull full-bridge structure to form a voltage output signal, and the second magnetic induction unit 212 adopts a push-pull full-bridge structure to form a voltage output signal. The two push-pull full-bridge structures form a double push-pull full-bridge differential structure, and the voltage output of the two push-pull full-bridge structures forms a differential voltage signal. The magnetic induction module 2 adopts a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated in the magnetic induction unit, the first magnetic induction unit 211, and the second magnetic induction unit 212 constitute a closed-loop magnetic field feedback. The output of the magnetic induction module 2 forms the output signal of the current sensor.

[0070] An embodiment of the present invention provides a fifth current sensor as shown in FIG. 4, and a cross-sectional view of the position where the magnetic induction unit is located is shown in FIG. 21, where the current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4, and the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, a copper bar area 12 for current shunt, a primary input terminal 13, and a primary output terminal 14.

[0071] Optionally, the primary current input copper bar 1 is an integrally formed copper bar, and the differential copper bar area 11, the current shunt copper bar area 12, the primary input terminal 13, and the primary output terminal 14 are located in the same horizontal plane. The differential copper bar area 11 and the current shunt copper bar area 12 are connected in parallel, and the connection points at the two ends are the primary input terminal 13 and the primary output terminal 14, respectively. After the current to be measured flows into the primary input terminal 13, the current to be measured is shunted through the differential copper bar area 11 and the current shunt copper bar area 12, and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, fix, and support various components in the current sensor.

[0072] The magnetic induction module 2 is fixed on the circuit board 3, and both are electrically insulated from the primary current input copper bar 1. The magnetic induction module 2 includes a third magnetic induction unit 213 with a vertically upward sensitive direction, and the third magnetic induction unit 213 uses a Hall element. As shown in FIG. 21, the vertical projection position of the third magnetic induction unit 213 is located inside the U-shaped enclosed area of ​​the U-shaped current conduction path, the current direction of the left current conduction path below it is inward perpendicular to the paper plane, and the current direction of the right current conduction path below it is outward perpendicular to the paper plane. The measured current generates a vertically downward magnetic field at the position of the third magnetic induction unit 213. The magnetic induction module 2 adopts an open-loop signal conditioning circuit, and the output of the magnetic induction module 2 forms the output signal of the current sensor.

[0073] An embodiment of the present invention provides a sixth current sensor as shown in FIG. 23, and a cross-sectional view of the position where the magnetic induction unit is installed is shown in FIG. 22, where the current sensor includes a primary current input copper bar 1, a magnetic induction module 2, a circuit board 3, and a mechanical support housing 4, and the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, a copper bar area 12 for current shunt, a primary input terminal 13, and a primary output terminal 14.

[0074] The current shunt copper bar area 12 is located below the plane where the differential copper bar area 11 is located. The differential copper bar area 11 and the current shunt copper bar area 12 are two independent copper bars connected in parallel, and the connection points at the two ends are the primary input terminal 13 and the primary output terminal 14, respectively. Except for the connection points at the two ends, the differential copper bar area 11 and the current shunt copper bar area 12, which are located in different planes, are insulated from each other. After the current to be measured flows into the primary input terminal 13, it is shunted through the differential copper bar area 11 and the current shunt copper bar area 12 and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, fix, and support various components in the current sensor.

[0075] The magnetic induction module 2 is fixed on the circuit board 3, and both are electrically insulated from the primary current input copper bar 1. The magnetic induction module 2 includes a third magnetic induction unit 213 and a fourth magnetic induction unit 214, which are located in the same horizontal plane and have a sensitive direction facing vertically upward. Both the third magnetic induction unit 213 and the fourth magnetic induction unit 214 use Hall elements. As shown in FIG. 22, the vertical projection position of the third magnetic induction unit 213 is located inside the U-shaped enclosed area of ​​the U-shaped current conduction path, the current direction of the left current conduction path below it is perpendicular to the paper surface and faces inward, and the current direction of the right current conduction path below it is perpendicular to the paper surface and faces outward. The current to be measured generates a vertically downward magnetic field at the position of the third magnetic induction unit 213. The vertical projection position of the fourth magnetic sensing unit 214 is located outside the U-shaped enclosed area of ​​the U-shaped current conduction path.

[0076] The magnetic induction module 2 employs an open-loop signal conditioning circuit to condition, amplify, and perform temperature compensation and linearity correction on the differential voltage signals of the third magnetic induction unit 213 and the fourth magnetic induction unit 214. The output of the magnetic induction module 2 forms the output signal of the current sensor.

[0077] In summary, the current sensor provided by each embodiment of the present invention has a large current measurement range, electrically isolates the input and output, can measure AC and DC currents, has adjustable sensitivity, and has strong resistance to external magnetic field interference. Compared with the prior art, the advantages of the current sensor provided by each embodiment of the present invention are as follows: the current measurement range is adjusted by parallel shunting the U-shaped structure current conduction path, and therefore the current input range can be adjusted by controlling the structure, amount, and plane of the copper bar area for current shunting, thereby realizing large current measurement without iron core, reducing the volume and weight; furthermore, the design of the current sensor is simplified by adopting integrated processing, the structure is simple, and the manufacturing cost is reduced. The current sensor provided by each embodiment of the present invention is applicable to magnetic induction units whose magnetic field sensitivity direction is perpendicular or parallel to the plane where the magnetic induction module is located. Its advantages are particularly reflected in the measurement of magnetoresistance devices with high sensitivity and small saturation field, such as GMR and TMR, thereby expanding the measurement range of magnetoresistance devices with high sensitivity and small saturation field. The current sensor has the characteristics of input and output electrical isolation, the ability to measure AC and DC currents, adjustable sensitivity, and strong resistance to external magnetic field interference.

[0078] It should be noted that the above description is merely the preferred embodiment of the present invention and the technical principles adopted. Those skilled in the art should understand that the present invention is not limited to the specific embodiment herein, and those skilled in the art can make various obvious modifications, rearrangements, mutual combinations, and substitutions without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail with respect to the above embodiment, the present invention is not limited to the above embodiment. Although the present invention has been described in detail with the above embodiment, the present invention is not limited to the above embodiment. It is also possible to include many other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. The current sensor includes a primary current input copper bar, a magnetic induction module, and a circuit board; The primary current input copper bar includes a primary input terminal, a primary output terminal, a differential copper bar region, and a current shunt copper bar region; The differential copper bar area and the current shunt copper bar area are electrically connected in parallel, the differential copper bar area includes a U-shaped current conduction path, the number of the current shunt copper bar areas is one or more, and either the current shunt copper bar area and the differential copper bar area are located in the same horizontal plane or in different horizontal planes; The number of the primary input terminals is one or more, the number of the primary output terminals is one or more, and either the primary input terminal or the primary output terminal is electrically connected to the differential copper bar area or the current shunt copper bar area; The primary current input copper bar is formed in one of the following two ways: (1) integrally formed; and (2) formed by connecting two or more independent copper bars, the independent copper bars including some or all of the primary input terminal, the primary output terminal, the differential copper bar area, and the current shunt copper bar area; The current sensor is characterized in that the magnetic induction module is fixed on the circuit board and located above the U-shaped current conduction path in the differential copper bar area, and an output of the magnetic induction module forms an output signal of the current sensor.

2. The magnetic induction module adopts one of the following three situations: (1) The magnetic induction module includes at least a first magnetic induction unit and a second magnetic induction unit therein, the first magnetic induction unit and the second magnetic induction unit are respectively located above two current conduction paths having a parallel positional relationship in the U-shaped current conduction path, the first magnetic induction unit and the second magnetic induction unit sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to a plane on which the magnetic induction module is located; (2) the magnetic induction module includes at least a third magnetic induction unit therein, the vertical projection position of the third magnetic induction unit is located inside the U-shaped enclosed area of ​​the U-shaped current conduction path, the third magnetic induction unit directly senses the magnetic field generated by the primary current input copper bar and generates a voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is perpendicular to the plane in which the magnetic induction module is located; (3) The current sensor of claim 1, wherein the magnetic induction module includes at least the third magnetic induction unit and the fourth magnetic induction unit therein, the vertical projection position of the fourth magnetic induction unit is located outside the U-shaped enclosed area of ​​the U-shaped current conduction path, the third magnetic induction unit and the fourth magnetic induction unit sense the magnetic field generated by the primary current input copper bar in a differential manner and generate a differential voltage signal, and the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is perpendicular to the plane in which the magnetic induction module is located.

3. the first magnetic induction unit and the second magnetic induction unit each include one or more magnetoresistive bridge arms, each of the magnetoresistive bridge arms being composed of one or more magnetoresistive sensing elements connected in series and parallel; In the first magnetic induction unit and the second magnetic induction unit, a bridge structure adopted by any of the magnetic induction units is one of a differential half-bridge structure, a differential full-bridge structure, a double push-pull half-bridge differential structure, and a double push-pull full-bridge differential structure; (1) the differential half-bridge structure is a single bridge, and the first magnetic induction unit and the second magnetic induction unit together configure the same single-bridge differential half-bridge structure to form an output signal of the differential half-bridge structure; (2) the differential full-bridge structure is a single bridge, and the first magnetic induction unit and the second magnetic induction unit together configure the same single-bridge differential full-bridge structure to form an output signal of the differential full-bridge structure; (3) In the double push-pull half-bridge differential structure, the first magnetic induction unit and the second magnetic induction unit both adopt a push-pull half-bridge structure, each forming a voltage output signal, and the voltage output signals of the two push-pull half-bridge structures differentially form an output signal of the double push-pull half-bridge differential structure; (4) The current sensor according to claim 2, characterized in that in the double push-pull full-bridge differential structure, the first magnetic induction unit and the second magnetic induction unit both adopt a push-pull full-bridge structure, each forming a voltage output signal, and the voltage output signals of the two push-pull full-bridge structures differentially form an output signal of the double push-pull full-bridge differential structure.

4. The current sensor of claim 1 , wherein two ends of the U-shaped opening of the U-shaped current conducting path are electrically connected.

5. 2. The current sensor according to claim 1, wherein the primary current input copper bar is electrically insulated from the magnetic induction module and the circuit board, respectively.

6. The current sensor of claim 1 , wherein the magnetic induction module further comprises a signal conditioning circuit, the signal conditioning circuit employing one of an open-loop signal conditioning circuit and a closed-loop signal conditioning circuit.

7. 10. The current sensor of claim 1, further comprising a mechanical support housing, said mechanical support housing serving to encase, secure and support various components within said current sensor.

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