Non-contact magnetoresistance current sensor
By designing a non-contact magnetoresistive current sensor, which uses spaced magnetoresistive sensors to form a Wheatstone bridge with the current-carrying conductor, the problems of large size, high cost and high power consumption of traditional current sensors are solved, realizing the design of miniaturized and low-cost current sensors.
Patent Information
- Application Number
- CN202422984356.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2034-12-04
AI Technical Summary
Traditional non-contact current sensors suffer from problems such as large size, high cost, and high power consumption, especially due to the increased resistance caused by the use of magnetic flux concentrators and local deformation of the current-carrying conductor.
A non-contact magnetoresistive current sensor was designed. The magnetoresistive sensor and the current-carrying conductor are spaced apart to form a Wheatstone bridge structure, which avoids the use of a magnetic flux concentrator. The current in the current-carrying conductor is sensed by the magnetoresistive sensor unit, and the signal is processed by the Wheatstone bridge.
This invention achieves a small, low-cost, and low-power current sensor, avoiding localized deformation of the current-carrying conductor and reducing resistance and power consumption.
Smart Images
Figure CN223565770U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a current sensor especially to a non-contact magnetic resistance current sensor. BACKGROUND
[0002] Traditionally, there are two methods to realize the non-contact current sensor: method one, using magnetic flux concentrator to shield the interference of the common mode magnetic field from the outside to the magnetic sensor, the disadvantage is that the volume is big and the cost is high; method two, locally deforming the current-carrying conductor to generate a differential magnetic field in the sensitive area of the magnetic sensor, the disadvantage is that the resistance and power consumption of the current-carrying conductor increase.
[0003] Therefore, it is necessary to provide a scheme to solve the above problems. SUMMARY
[0004] One of the purposes of the utility model is to provide a non-contact magnetic resistance current sensor, on the one hand, the use of the magnetic flux concentrator is avoided, the volume is small, the cost is low, on the other hand, the local deformation of the current-carrying conductor is avoided, the resistance is small, and the power consumption is low.
[0005] To solve the above problems, the utility model provides a non-contact magnetic resistance current sensor, which comprises: a current-carrying conductor; a magnetic resistance sensor located on one side of the current-carrying conductor and spaced from the current-carrying conductor, wherein the center line of the magnetic resistance sensor is aligned with one edge of the current-carrying conductor.
[0006] Further, the magnetic resistance sensor comprises a first magnetic sensitive area located on one side of the center line and a second magnetic sensitive area located on the other side of the center line.
[0007] Further, the first magnetic sensitive area comprises a first magnetic resistance sensor unit and a second magnetic resistance sensor unit, the second magnetic sensitive area comprises a third magnetic resistance sensor unit and a fourth magnetic resistance sensor unit, the first magnetic resistance sensor unit, the second magnetic resistance sensor unit, the third magnetic resistance sensor unit and the fourth magnetic resistance sensor unit are interconnected to form a Wheatstone bridge to sense the current flowing in the current-carrying conductor.
[0008] Further, each magnetic resistance sensor unit comprises a magnetic resistance strip and a plurality of short-circuit strips, the length extension direction of the magnetic resistance strip is parallel to the current direction in the current-carrying conductor, the short-circuit strips form a predetermined included angle with the magnetic resistance strip, and the plurality of short-circuit strips of each magnetic resistance sensor unit are parallel to each other.
[0009] Compared with the prior art, the non-contact magnetic resistance current sensor in the utility model: on the one hand, the use of the magnetic flux concentrator is avoided, the volume is small, and the cost is low; on the other hand, the local deformation of the current-carrying conductor is avoided, the resistance is small, and the power consumption is low. BRIEF DESCRIPTION OF DRAWINGS
[0010] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:
[0011] Figure 1 It is a top view structural schematic diagram of the non-contact magnetic resistance current sensor involved in the present application.
[0012] Figure 2 It is a top view structural schematic diagram of the non-contact magnetic resistance current sensor involved in the present application. Figure 1 It is a sectional view structural schematic diagram of the non-contact magnetic resistance current sensor 100 along AA. As shown in the figure,
[0013] Figure 3 It is a relationship curve of coupling strength and distance between the current-carrying conductor center and the magnetic resistance sensor center involved in the present application.
[0014] Figure 4 It is a voltage output characteristic curve of the non-contact magnetic resistance current sensor involved in the present application. DETAILED DESCRIPTION
[0015] In order to make the above-mentioned purpose, features and advantages of the present application more apparent, obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.
[0016] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "positive", "back", "left", "right", "vertical", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0017] Figure 1 It is a top view structural schematic diagram of the non-contact magnetic resistance current sensor 100 involved in the present application, Figure 2 It is a top view structural schematic diagram of the non-contact magnetic resistance current sensor 100 involved in the present application, Figure 1 It is a sectional view structural schematic diagram of the non-contact magnetic resistance current sensor 100 along AA. As shown in the figure, Figure 1 and 2As shown, the non-contact magnetoresistive current sensor 100 comprises a current-carrying conductor 102 and a magnetoresistive sensor 101 located above and spaced from the current-carrying conductor 102, wherein the center line of the magnetoresistive sensor 101 is aligned with one edge of the current-carrying conductor 102 to obtain the maximum coupling strength. As shown in the figure, the current-carrying conductor 102 is a rectangular conductor, and the magnetoresistive sensor 101 is a rectangular sensor. Figure 2 As shown, the center line of the magnetoresistive sensor 101 is aligned with one edge of the current-carrying conductor 102 means that the center line of the magnetoresistive sensor 101 and the vertical projection of one edge of the current-carrying conductor 102 are superimposed. Of course, according to the orientation of the non-contact magnetoresistive current sensor 100 in the figure, the magnetoresistive sensor 101 can also be considered to be located below, left or right of the current-carrying conductor 102. Therefore, in order to avoid confusion, it can be considered that the magnetoresistive sensor 101 is located on one side of the current-carrying conductor 102. The magnetoresistive sensor 101 is spaced from the current-carrying conductor 102 means that the magnetoresistive sensor 101 and the current-carrying conductor 102 are not in contact, and the magnetoresistive sensor 101 and the current-carrying conductor 102 are spaced from each other by a predetermined distance or a certain distance. Figure 2 As shown, the center line of the magnetoresistive sensor 101 is aligned with one edge of the current-carrying conductor 102 means that the center line of the magnetoresistive sensor 101 and the vertical projection of one edge of the current-carrying conductor 102 are superimposed. Of course, according to the orientation of the non-contact magnetoresistive current sensor 100 in the figure, the magnetoresistive sensor 101 can also be considered to be located below, left or right of the current-carrying conductor 102. Therefore, in order to avoid confusion, it can be considered that the magnetoresistive sensor 101 is located on one side of the current-carrying conductor 102. The magnetoresistive sensor 101 is spaced from the current-carrying conductor 102 means that the magnetoresistive sensor 101 and the current-carrying conductor 102 are not in contact, and the magnetoresistive sensor 101 and the current-carrying conductor 102 are spaced from each other by a predetermined distance or a certain distance.
[0018] The magnetoresistive sensor 101 comprises a first magnetic sensitive area 101a located on one side of the center line and a second magnetic sensitive area 101b located on the other side of the center line. That is, the center line is the center line between the first magnetic sensitive area 101a and the second magnetic sensitive area 101b, the distance from the center line to the center line of the first magnetic sensitive area 101a is equal to the distance from the center line to the center line of the second magnetic sensitive area 101b, and the center line of the magnetoresistive sensor 101 is parallel to the current direction of the current-carrying conductor 102 and the edge of the current-carrying conductor 102. The first magnetic sensitive area 101a comprises a first magnetic resistance sensor unit 1011a and a second magnetic resistance sensor unit 1012a, and the second magnetic sensitive area 101b comprises a third magnetic resistance sensor unit 1011b and a fourth magnetic resistance sensor unit 1012b. The first magnetic resistance sensor unit 1011a, the second magnetic resistance sensor unit 1012a, the third magnetic resistance sensor unit 1011b and the fourth magnetic resistance sensor unit 1012b are interconnected to form a Wheatstone bridge. The magnetic field generated by the current I flowing in the current-carrying conductor 102 in the first magnetic sensitive area 101a is H1, the magnetic field generated by the current-carrying conductor 102 in the second magnetic sensitive area 101b is H2, and the common mode magnetic field in the external environment in the first magnetic sensitive area 101a and the second magnetic sensitive area 101b is H0. The Wheatstone bridge only senses the magnetic field (H1-H2) / 2 generated by the current I flowing in the current-carrying conductor 102, and is completely insensitive to the external common mode magnetic field H0.
[0019] Each of the magnetoresistance sensor units comprises a magnetoresistance strip 103 and a plurality of short-circuit strips 104. The length extension direction of the magnetoresistance strip is parallel to the current direction in the current-carrying conductor 102 and the edge of the current-carrying conductor 102, the short-circuit strips 104 form a predetermined included angle with the magnetoresistance strip 103, and the plurality of short-circuit strips 104 are parallel to each other. Specifically, the first connection end of the first magnetoresistance sensor unit 1011a and the first connection end of the third magnetoresistance sensor unit 1011b are connected to the power supply end VDD, the first connection end of the second magnetoresistance sensor unit 1012a and the first connection end of the fourth magnetoresistance sensor unit 1012b are connected to the ground end GND, the second connection end of the first magnetoresistance sensor unit 1011a and the second connection end of the second magnetoresistance sensor unit 1012a are connected to the first voltage output end Vout1, the second connection end of the third magnetoresistance sensor unit 1011b and the second connection end of the fourth magnetoresistance sensor unit 1012b are connected to the second voltage output end Vout2, the first connection end of each magnetoresistance sensor unit is located on the same side, and the second connection end of each magnetoresistance sensor unit is located on the same side. The short-circuit strips of the first magnetoresistance sensor unit and the third magnetoresistance sensor unit are parallel to each other, the short-circuit strips of the second magnetoresistance sensor unit and the fourth magnetoresistance sensor unit are parallel to each other, and the short-circuit strips of the first magnetoresistance sensor unit and the second magnetoresistance sensor unit form an included angle. The working principle of each magnetoresistance sensor unit and the Wheatstone bridge can refer to the prior art, which is not the focus of the present application and will not be described here.
[0020] Referring to Figure 3 As shown in the figure, the relationship curve of the coupling strength (H1-H2) / (2I) and the center distance dxx of the current-carrying conductor 102 and the magnetoresistance sensor 101 along the x-axis, wherein in this example, the center distance d between the first magnetic sensitive area 101a and the second magnetic sensitive area 101b is 1mm, the width W of the current-carrying conductor 101 is 20mm, and the center distance dzz of the current-carrying conductor 102 and the magnetoresistance sensor 101 along the z-axis is 3mm. It can be seen that when the center line of the magnetoresistance sensor 101 and the edge of the current-carrying conductor 102 are aligned (dxx=W / 2=10mm), the coupling strength (H1-H2) / (2I) is maximum.
[0021] Referring to Figure 4As shown, the voltage output characteristic curve 400 of the non-contact magnetoresistive current sensor 100, wherein the center line of the magnetoresistive sensor 101 and the edge of the current-carrying conductor 102 are aligned, in this example, the center distance d between the first magnetic sensitive area 101a and the second magnetic sensitive area 101b is 1mm, the width W of the current-carrying conductor 102 is 20mm, the center distance dzz of the current-carrying conductor 102 and the magnetoresistive sensor 101 along the z axis is 3mm. It can be seen that the voltage output (Vout1-Vout2) / VDD of the Wheatstone bridge linearly responds to the current I flowing in the current-carrying conductor 102.
[0022] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application.
[0023] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications and variations to the above embodiments within the scope of the present application.
Claims
1. A non-contact magnetoresistive current sensor, characterized by, It comprises: a current-carrying conductor; a magnetoresistance sensor located on one side of the current-carrying conductor and spaced from the current-carrying conductor, wherein a center line of the magnetoresistance sensor is aligned with one edge of the current-carrying conductor.
2. The non-contact magnetoresistive current sensor of claim 1, wherein, The magnetoresistance sensor comprises a first magnetic sensitive area located on one side of the center line and a second magnetic sensitive area located on the other side of the center line.
3. The non-contact magnetoresistive current sensor of claim 2, wherein, The first magnetic sensitive area comprises a first magnetoresistance sensor unit and a second magnetoresistance sensor unit, and the second magnetic sensitive area comprises a third magnetoresistance sensor unit and a fourth magnetoresistance sensor unit, the first magnetoresistance sensor unit, the second magnetoresistance sensor unit, the third magnetoresistance sensor unit and the fourth magnetoresistance sensor unit are interconnected to form a Wheatstone bridge to sense the current flowing in the current-carrying conductor.
4. The non-contact magnetoresistive current sensor of claim 3, wherein, Each magnetoresistance sensor unit comprises a magnetoresistance strip and a plurality of short-circuit strips, the length extension direction of the magnetoresistance strip is parallel to the current direction in the current-carrying conductor, the short-circuit strips form a predetermined included angle with the magnetoresistance strip, and the plurality of short-circuit strips of each magnetoresistance sensor unit are parallel to each other.
5. The non-contact magnetoresistance current sensor according to claim 3, wherein the first connection end of the first magnetoresistance sensor unit and the first connection end of the third magnetoresistance sensor unit are connected to a power supply end VDD, the first connection end of the second magnetoresistance sensor unit and the first connection end of the fourth magnetoresistance sensor unit are connected to a ground end GND, the second connection end of the first magnetoresistance sensor unit and the second connection end of the second magnetoresistance sensor unit are connected to a first voltage output end Vout1, the second connection end of the third magnetoresistance sensor unit and the second connection end of the fourth magnetoresistance sensor unit are connected to a second voltage output end Vout2, the first connection end of each magnetoresistance sensor unit is located on the same side, and the second connection end of each magnetoresistance sensor unit is located on the same side.
6. The non-contact magnetoresistance current sensor according to claim 5, wherein the short-circuit strips of the first magnetoresistance sensor unit and the third magnetoresistance sensor unit are parallel to each other, the short-circuit strips of the second magnetoresistance sensor unit and the fourth magnetoresistance sensor unit are parallel to each other, the short-circuit strips of the first magnetoresistance sensor unit and the second magnetoresistance sensor unit form an included angle.