Current Sensor

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 INVENTION Embodiments of the present invention relate to the technical field of electrical measurements, and in particular to current sensors. [Background technology]

[0002] A current sensor is a type of current detection device that can convert and output the detected current information into an electrical signal or information in a desired form that meets 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. Currently, the most widely used current sensor is the magnetic current sensor, which mainly includes fluxgate current sensors, Hall current sensors, and magnetoresistive current sensors.

[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 Hall current sensor technology is mature, it suffers from low sensitivity, poor temperature drift, and small bandwidth. Its magnetic field sensitivity direction is perpendicular to the plane in which the Hall element is located. There are two main current input methods for Hall current sensors: one senses the magnetic field of the current conductor being measured through a relatively large ring-shaped iron core; the other is a small chip-level current sensor in which the current being measured is directly input into a U-shaped copper conduction path, resulting in a smaller measurement range than the former.

[0005] Magnetoresistive 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 on which the magnetoresistive device is located, achieving high sensitivity and good linearity. However, magnetoresistive devices with high sensitivity generally have a small saturation field, and their internal magnetoresistive sensing elements tend to become magnetically saturated during large current measurements, resulting in a small current measurement range, which affects their range of use. Magnetoresistive current sensors' measured current input methods 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 current to be measured 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 current to be measured is input into a copper strip with a neck depression; (4) in patent application number 201811455342.7, the current to be measured is input into a copper bar-type conductor to be measured with a rectangular or rounded rectangular cross section; in this type of input method, the single current input path is prone to exceeding the linear operating range of the magnetoresistive sensing element and easily saturating 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] 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 region and the current shunt copper bar region are electrically connected in parallel, the differential copper bar region includes a U-shaped current conduction path, the number of the current shunt copper bar regions is one or more, and either the current shunt copper bar region or the differential copper bar region is located in the same horizontal plane or in different horizontal planes; The number of primary input terminals is one or more, the number of 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) by connecting two or more independent copper bars, and the independent copper bars include some or all of the primary input terminal, primary output terminal, differential copper bar area, and current shunt copper bar area; 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 input and output, can measure AC and DC currents, has adjustable sensitivity, and is highly resistant 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 the current input range can be adjusted by controlling the structure, quantity, and plane of the copper bar area for the current shunt, thereby achieving large current measurement without an iron core and reducing volume and weight. Furthermore, the design of the current sensor is simplified by adopting integrated processing, the structure is simple, and manufacturing costs are reduced. It is suitable for magnetic induction units whose magnetic field sensitivity direction is perpendicular to or parallel to the plane in which the magnetic induction module is located. It extends the measurement range of magnetoresistive devices with high sensitivity and small saturation field, and has the characteristics of electrically isolated input and output, the 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 it is clear to those skilled in the art that 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 all fall within the scope of the claims of the present invention. [Brief explanation of the drawings]

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

[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 described embodiment is not all embodiments of the present invention, but some embodiments of the present invention. Based on the basic concepts 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 current shunt copper bar areas is one or more, any current shunt copper bar area and any differential copper bus area are located in the same horizontal plane or in different horizontal planes, the number of primary input terminals is one or more, the number of primary output terminals is one or more, the primary input terminal is one or more, and any one of the primary output terminals 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 situations, namely (1) integrally formed, or (2) formed by connecting two or more independent copper bars, the independent copper bars including some or all of the primary input terminal, primary output terminal, differential copper bar area, and current shunt copper bar area, 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 current to be measured into the input magnetic field of the magnetic induction module through the primary current input copper bar. This allows for large current measurement without the need for an iron core, reduces volume and weight, has a simple structure and low processing costs, and extends the measurement range of the magnetoresistive device with high sensitivity and a small saturation field. It has the following characteristics: input and output electrical isolation, the ability to measure AC and DC currents, 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, 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 on which the magnetic induction module is located; (2) the magnetic induction module includes at least a third magnetic induction unit therein, and 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, and 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 on 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 differentially sense the magnetic field generated by the primary current input copper bar 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, the 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 form the same single-bridge differential half-bridge structure, forming 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 form the same single-bridge differential full-bridge structure, forming 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 the 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 the 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 this 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 referred to as a primary current conductor or copper primary conduction path, which mainly functions to introduce the current to be measured into 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 an anti-parallel current relationship, and therefore includes, but is not limited to, similar shapes such as an "Ω" shape, an "n" shape, 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 conduction path. As shown in FIG. 1, the existing U-shaped copper conduction path is a single-layer U-shaped copper conduction path, i.e., a U-shaped copper bar. The horizontal rightward direction in the plane of the U-shaped copper bar is the positive x-axis direction, the vertical upward direction in the plane of the U-shaped copper bar is the positive y-axis direction, and the direction perpendicular to the plane of the U-shaped copper bar is the z-axis direction. The current to be measured is directly input into the single-layer U-shaped copper conduction path. Two magnetic induction units 211 and 212 are located in the same plane and above the U-shaped copper bar. That is, the vertical projection of the U-shaped copper bar along the z-direction covers the two magnetic induction units 211 and 212.

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

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

[0024] Referring to FIG. 4, FIG. 4 is a schematic diagram of a primary current input copper bar according to one embodiment of the present invention. In this embodiment, the primary current input copper bar includes a differential copper bar region 11, which has a U-shaped current conduction path as shown in FIG. 1 . The primary current input copper bar also includes a current shunt copper bar region 12, where the differential copper bar region 11 and the current shunt copper bar region 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 regions may be two or more, and the current shunt copper bar region and the differential copper bar region may 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 being located inside the U-shaped enclosed area of ​​the U-shaped current conduction path 11, the third magnetic induction unit 213 directly sensing the magnetic field generated by the primary current input copper bar and generating a voltage signal, the magnetic field sensitivity direction of the magnetic induction unit used by the current sensor being perpendicular to the plane in which the magnetic induction module is located, and the third magnetic induction unit 213 and the U-shaped current conduction path 11 are located on the same plane.

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

[0027] Compared with the magnetic induction unit shown in FIG. 1, for a magnetic induction unit with the same magnetic field measurement range, the structure shown in FIG. 4 can achieve an increased current measurement range. From the simulation results of the z-component of the magnetic field in FIG. 6, it can be seen that the x-component and 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 a position where the x-coordinate is zero and using non-differential measurement. 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 at a different position and using differential measurement.

[0028] Referring to Fig. 7, there is shown a schematic diagram of another primary current input copper bar provided in one embodiment of the present invention, and referring to Fig. 8, there is shown 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. In this embodiment, the differential copper bar region 11 and the U-shaped current shunt copper bar region 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. The first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two parallel current conduction paths in the U-shaped current conduction path 11. The first magnetic induction unit 211 and the second magnetic induction unit 212 differentially sense the magnetic field generated by the primary current input copper bar and generate a differential voltage signal. The magnetic field sensitivity direction of the magnetic induction unit used by the current sensor is parallel to the plane on which 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 in 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 a range of -4.5 mT to +4.5 mT along the x-axis.

[0031] Referring to Fig. 9, there is shown a schematic diagram of yet another primary current input copper bar provided in an embodiment of the present invention, and referring to Fig. 10, there is shown 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. 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, which are respectively located above two parallel current conduction paths in the U-shaped current conduction path 11, and the first magnetic induction unit 211 and the second magnetic induction unit 212 differentially sense the magnetic field generated by the primary current input copper bar 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 on which 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 in 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 a range of -3 mT to +3 mT along the x-axis.

[0034] 11 shows a schematic diagram of yet another primary-side current input copper bar provided in an embodiment of the present invention, and FIG. 12 shows 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. As shown in FIG. 11, optionally, two ends of the U-shaped opening of the U-shaped current conduction path are electrically connected. The differential copper bar region 11 and the U-shaped current shunt copper bar region 12 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 conduction path in the differential copper bar region 11 are connected to form a new current conduction 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, which are respectively located above two parallel current conduction paths in the U-shaped current conduction path 11, and the first magnetic induction unit 211 and the second magnetic induction unit 212 differentially sense the magnetic field generated by the primary current input copper bar 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 on which 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 in 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 a range of -1.4 mT to +1.4 mT along the x-axis.

[0037] The above embodiments provide that the differential copper bar area of ​​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 differently designed current shunt copper bar areas can have a significant impact 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, from the above embodiments, it can be seen 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 symmetric characteristics. Therefore, the current can be detected by differential measurement by arranging the magnetic sensing units with their sensitivity directions along the in-plane x-axis at different positions.

[0039] Below is a brief description of 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 being respectively located above two current conduction paths having a parallel positional relationship within the U-shaped current conduction path, the first magnetic induction unit and the second magnetic induction unit differentially sense the magnetic field generated by the primary current input copper bar 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 a current to be measured 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 assumption is 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 to the left at the position of the second magnetic induction unit 212.

[0042] Referring to Figure 13, Figure 13 is a schematic diagram illustrating 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 magnetoresistive bridge arm 211a, and the second magnetic induction unit 212 includes a magnetoresistive bridge arm 212a. The two magnetoresistive 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 a current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. Under the aforementioned conditions, when a differential-mode magnetic field is sensed, the resistance of the magnetic resistance bridge arm 211a decreases and the resistance of the magnetic resistance bridge arm 212a increases. According to Biot-Savart's law, the Vout output changes linearly with the magnitude of the measured current. Because the sensitivity directions of the first magnetic induction unit 211 and the second magnetic induction unit 212 in the differential half-bridge structure are the same, in an external uniform magnetic field (i.e., a common-mode magnetic field), the resistances of the two magnetic resistance bridge arms 211a and 212a increase or decrease simultaneously. At this time, the Vout output has no response, thus providing good resistance to common-mode magnetic field interference.

[0044] Referring to Figure 14, Figure 14 is a schematic diagram illustrating 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 magnetoresistive bridge arms 211b1 and 211b2, and the second magnetic induction unit 212 includes two magnetoresistive bridge arms 212b1 and 212b2. The sensitivity directions of the four magnetoresistive bridge arms 211b1, 211b2, 212b1, and 212b2 are all aligned and point to the right, forming 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 a current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. Under the above conditions, when a differential-mode magnetic field is sensed, the resistances of the magnetoresistive bridge arms 211b1 and 211b2 decrease, while the resistances of the magnetoresistive bridge arms 212b1 and 212b2 increase. As a result, the output voltage V1 decreases, and the output voltage 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, because the sensitivity directions of the four magnetoresistive bridge arms 211b1, 211b2, 212b1, and 212b2 are aligned, in the case of an external uniform magnetic field (i.e., a common-mode magnetic field), the resistances of the four magnetoresistive bridge arms 211b1, 211b2, 212b1, and 212b2 simultaneously increase or decrease. At this time, the Vout output has no response and therefore has good resistance to common-mode magnetic field interference.

[0046] Referring to Figure 15, Figure 15 is a schematic diagram illustrating 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, and the second magnetic induction unit 212 forms a push-pull half-bridge structure. 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 and approximately the same structure and characteristics. Specifically, the first magnetic induction unit 211 includes two reluctance bridge arms 211c1 and 211c2, forming a push-pull half-bridge structure with an output V1c. The second magnetic induction unit 212 includes two reluctance 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 reluctance bridge arms 211c1 and 212c1 of the two magnetic induction units is to the left, while the sensitivity direction of the lower reluctance bridge arms 211c2 and 212c2 is to the right. When a current to be measured is input to the primary current input copper bar, the magnetic induction module senses the magnetic field. When a differential-mode magnetic field is sensed under the above conditions, the resistance values ​​of the reluctance bridge arms 211c2 and 212c1 decrease, while the resistance values ​​of the reluctance bridge arms 211c1 and 212c2 increase. As a result, the output voltage V1c decreases, and the output voltage 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 Figure 16, Figure 16 is a schematic diagram illustrating 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. 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 and 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 magnetoresistive 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 magnetoresistive bridge arms 211d2, 211d3, 212d2, and 212d3 is leftward, and the sensitivity direction of the four magnetoresistive bridge arms 211d1, 211d4, 212d1, and 212d4 is rightward. When the current to be measured is input to the primary current input copper bar, the magnetic induction module senses a magnetic field. Under the above conditions, when a differential mode magnetic field is sensed, the resistance values ​​of the four magnetoresistive bridge arms 211d1, 211d4, 212d2, and 212d3 decrease, and the resistance values ​​of the four magnetoresistive bridge arms 211d2, 211d3, 212d1, and 212d4 increase, causing both the output voltage values ​​V1d2 and V2d1 to decrease and both the output voltage values ​​V1d1 and V2d2 to increase. The difference V1d between V1d1 and V1d2 is positive, and the difference V2d between V2d1 and V2d2 is negative. Therefore, the output signal Vout 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 resistance to common mode magnetic field interference.

[0050] In addition to the four typical bridge structures described above, the structure of the magnetic induction module can also be modified based on the same principle according to specific application circumstances, such as differential output of half-bridge structure and full-bridge structure, setting of sensitivity direction of each bridge arm, setting of two or more magnetic induction units, etc., 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 employs 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 one embodiment of the present invention. Please refer to FIG. 18, which is a schematic diagram of another current sensor provided in one embodiment of the present invention. Please refer to FIG. 19, which is a schematic diagram of yet another current sensor provided in one 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 magnetic induction module is amplified and then drives the magnetic field feedback coil 22 to generate a feedback magnetic field. 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 magnetic field dynamic balance is achieved, the first magnetic induction unit 211 and the second magnetic induction unit 212 operate under the same common-mode magnetic field conditions, and the feedback current of the magnetic field feedback coil 22 is sampled through 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 on which the magnetic field feedback coil 22 is located is parallel to the plane on which the first magnetic induction unit 211 and the second magnetic induction unit 212 are located. The magnetic field feedback coils 22 are 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, and further, 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] For example, if the magnetic field direction of the current to be measured is rightward at the position of the first magnetic induction unit 211 and leftward at the position of the second magnetic induction unit 212, the current direction of the conductor horizontally disposed below the first magnetic induction unit 211 of the magnetic field feedback coil 22 is outward and perpendicular to the paper, and the current direction of the conductor horizontally disposed below the second magnetic induction unit 212 of the magnetic field feedback coil 22 is inward and perpendicular to the paper, so that the magnetic field feedback coil 22 generates a horizontally leftward feedback magnetic field at the first magnetic induction unit 211 and a horizontally rightward feedback magnetic field at the second magnetic induction unit 212, thereby offsetting the differential mode magnetic field generated by the current to be measured and thereby achieving 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 coils 22 are integrated inside the first magnetic induction unit 211 and the second magnetic induction unit 212. In other embodiments, the magnetic field feedback coils can be optionally integrated at other positions not limited to the positions shown in the above figures. Although the distribution or connection of the magnetic field feedback coils is slightly different, the feedback magnetic field generated by the magnetic field feedback coils is always used to offset the differential mode magnetic field generated by the current to be measured, and finally, the detection of the current to be measured is realized.

[0057] Based on the above structure, the overall structure of the current sensor provided by this embodiment of the present invention will be 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, 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, where the primary current input copper bar 1 includes a differential copper bar area 11 including a U-shaped current conduction path, a current shunt copper bar area 12, 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 current shunt copper bar area 12, 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 current shunt copper bar area 12 are connected in parallel, and the connection points at their 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 within 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, which are located in the same horizontal plane and have their sensitivity directions pointing horizontally to the right. The first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two parallel current conduction paths in the U-shaped current conduction path of the differential copper bar region 11. 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 magnetoresistive sensing elements used by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both tunnel magnetoresistors (TMRs). As shown in FIG. 13, the two magnetic induction units each include a magnetoresistive bridge arm. The first magnetic induction unit 211 and the second magnetic induction unit 212 together form the same single-bridge differential half-bridge structure, which differentially senses the differential-mode magnetic field generated by the primary current input copper bar 1 and generates a differential voltage signal. The magnetic induction module 2 employs a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated into the magnetic induction module 2, the first magnetic induction unit 211, and the second magnetic induction unit 212 together form 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 current shunt copper bar area 12, a primary input terminal 13, and a primary output terminal 14.

[0062] Optionally, the current shunt copper bar area 12 is located above or 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, with the connection points at their two ends corresponding to the primary input terminal 13 and the primary output terminal 14, respectively. Except for the connection points at their 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 encases, fixes, and supports various components within 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, which are located in the same horizontal plane and have their sensitivity directions pointing horizontally to the right. The first magnetic induction unit 211 and the second magnetic induction unit 212 are respectively located above two parallel current conduction paths in the U-shaped current conduction path of the differential copper bar region 11. 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 magnetoresistive sensing elements used by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both giant magnetoresistors (GMRs). As shown in FIG. 14, each of the two magnetic induction units includes two magnetoresistive bridge arms. The first magnetic induction unit 211 and the second magnetic induction unit 212 together form the same single-bridge differential full-bridge structure, which differentially senses the differential-mode magnetic field generated by the primary current input copper bar 1 and generates a differential voltage signal. The magnetic induction module 2 employs a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated into the magnetic circuit board 3, the first magnetic induction unit 211, and the second magnetic induction unit 212 together form 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 includes 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 conduction path through another third current conduction 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 employs a push-pull half-bridge structure to generate a voltage output signal, the second magnetic induction unit 212 employs a push-pull half-bridge structure to generate a voltage output signal, and the two push-pull half-bridge structures form a double push-pull half-bridge differential structure, with the voltage output of the two push-pull half-bridge structures forming a differential voltage signal. The magnetic induction module 2 employs 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. As 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, 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 and 122 are connected in parallel, and the connection points at their 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, fix and support the various components within the current sensor.

[0068] The magnetic induction module 2 is fixed on a 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 their sensitivity directions pointing horizontally to the right. As shown in FIG. 19, the first magnetic induction unit 211 and the second magnetic induction unit 212 are located above two parallel current conduction paths within the U-shaped structure of the differential copper bar region 11. The current flow direction of the current conduction path below the first magnetic induction unit 211 is inward, perpendicular to the paper, and the current flow direction of the current conduction path below the second magnetic induction unit 212 is outward, perpendicular to the paper.

[0069] The magnetoresistive sensing elements employed by the first magnetic induction unit 211 and the second magnetic induction unit 212 are both tunnel magnetoresistors (TMRs). Each magnetic induction unit includes a push-pull full-bridge structure composed of four magnetoresistive bridge arms. As shown in FIG. 16, the first magnetic induction unit 211 employs a push-pull full-bridge structure to generate a voltage output signal, and the second magnetic induction unit 212 employs a push-pull full-bridge structure to generate a voltage output signal. The two push-pull full-bridge structures form a double push-pull full-bridge differential structure, and the voltage outputs of the two push-pull full-bridge structures form a differential voltage signal. The magnetic induction module 2 employs a closed-loop signal conditioning circuit. The closed-loop signal conditioning circuit, the magnetic field feedback coil 22 integrated into 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 current shunt copper bar area 12, 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 region 11, the current shunt copper bar region 12, the primary input terminal 13, and the primary output terminal 14 are located in the same horizontal plane. The differential copper bar region 11 and the current shunt copper bar region 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 region 11 and the current shunt copper bar region 12 and flows out from the primary output terminal 14. The mechanical support housing 4 serves to encase, fix, and support various components within the current sensor.

[0072] The magnetic induction module 2 is fixed on a circuit board 3, and both are electrically isolated from the primary current input copper bar 1. The magnetic induction module 2 includes a third magnetic induction unit 213 with a vertically upward sensitivity direction. The third magnetic induction unit 213 uses a Hall element. As shown in Figure 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 plane of the paper, and the current direction of the right current conduction path below it is outward, perpendicular to the plane of the paper. The current to be measured generates a vertically downward magnetic field at the location of the third magnetic induction unit 213. The magnetic induction module 2 employs 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. 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.

[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 their two ends are the primary input terminal 13 and the primary output terminal 14, respectively. Except for the connection points at their 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 the various components within 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 sensitivity directions 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 of the third magnetic induction unit 213 is located inside the enclosed U-shaped area of ​​the U-shaped current conduction path, with the current flowing in the left current conduction path below it facing inward perpendicular to the paper surface, and the current flowing in the right current conduction path below it facing outward perpendicular to the paper surface. The current to be measured generates a vertically downward magnetic field at the location of the third magnetic induction unit 213. The vertical projection of the fourth magnetic sensing unit 214 is located outside the enclosed U-shaped 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 input and output, can measure AC and DC currents, has adjustable sensitivity, and is highly resistant to external magnetic field interference. Compared with 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 current conduction path, and the current input range can be adjusted by controlling the structure, quantity, and plane of the copper bar area for the current shunt, thereby achieving large current measurement without an iron core and reducing volume and weight. Furthermore, the design of the current sensor is simplified by adopting an integrated process, resulting in a simple structure and reduced manufacturing costs. 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 in which the magnetic induction module is located. This advantage is particularly reflected in the measurement of magnetoresistive devices with high sensitivity and small saturation fields, such as GMR and TMR, thereby extending the measurement range of magnetoresistive devices with high sensitivity and small saturation fields. 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 a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art should understand that the present invention is not limited to the specific embodiments herein, and that those skilled in the art can make various obvious modifications, rearrangements, mutual combinations, and substitutions without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above embodiments. Although the present invention has been described in detail using the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included 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 area, and a current shunt copper bar area; the differential copper bar region and the current shunt copper bar region are electrically connected in parallel, the differential copper bar region includes a U-shaped current conduction path and copper bar portions extending continuously from both ends of the U-shaped current conduction path outward along a direction intersecting an opening direction of the U-shaped current conduction path, the number of the current shunt copper bar regions is one or more, and either the current shunt copper bar region or the differential copper bar region is located in the same horizontal plane or in different horizontal planes; the number of the primary side input terminals is one or more, the number of the primary side output terminals is one or more, and either the primary side input terminal or the primary side 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) 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 magnetic induction module is fixed on the circuit board and positioned above the U-shaped current conduction path within the differential copper bar region, and the output of the magnetic induction module forms the output signal of the current sensor.

2. The magnetic induction module may adopt 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, 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 differentially sense the magnetic field generated by the primary current input copper bar 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 on 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 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.

3. the first magnetic induction unit and the second magnetic induction unit each include one or more magnetoresistive bridge arms, each of which is 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 either 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 form the same single-bridge differential half-bridge structure, forming 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, wherein 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. 2. The current sensor according to 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 isolated from the magnetic induction module and the circuit board, respectively.

6. 10. 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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