Direct insertion type three-axis broadband magnetic field sensor, preparation method and application method

Abstract

The invention discloses a direct insertion type three-axis broadband magnetic field sensor, a preparation method and an application method, and belongs to the technical field of magnetic field sensors. The direct insertion type three-axis broadband magnetic field sensor comprises a horizontal substrate and a vertical substrate which are vertically inserted; magnetic resistance coil combined type Wheatstone full-bridge induction circuits which are perpendicular to each other are arranged on the horizontal substrate and used for detecting magnetic fields in the X-axis direction and the Y-axis direction, jacks are formed in the horizontal substrate, the vertical substrate is inserted into the jacks and welded to the welding disc, and a magnetic resistance coil combined type Wheatstone full-bridge induction circuit used for detecting the Z-axis direction is arranged on the vertical substrate. Meanwhile, the invention discloses a preparation method and an application method based on the sensor, by adopting the direct insertion type three-axis broadband magnetic field sensor, the preparation method and the application method, the magnetic field frequency measurement range of the sensor is expanded by adopting a magnetic resistance coil combined Wheatstone full-bridge induction circuit, and the sensor has high signal-to-noise ratio and small size.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic field sensors, and in particular to a direct-insertion three-axis wide-band magnetic field sensor, a preparation method and an application method. Background Art

[0002] A magnetic field sensor is a device that can convert magnetic field changes caused by various changes into electrical signals. With the rapid development of information industry, industrial automation, transportation, power electronics technology, office automation, household appliances, medical instruments, etc. and the popularization of electronic computer applications, a large number of sensors are needed to convert non-electrical parameters that need to be measured and controlled into easy-to-process electrical parameter signals.

[0003] Magnetic field sensors are widely used in various magnetic field measurement fields, such as industry, transportation, consumer electronics, medical and non-destructive testing. In the industrial field, magnetic sensors can be used for accurate measurement of displacement of various metal parts, current measurement of large machinery and instruments, automation control of industrial systems, monitoring of current such as power supplies and inverters, and energy management of distributed power grids. In the field of transportation, magnetic sensors are widely used in systems such as subways, cars, ships, airplanes and high-speed railways. For example, real-time monitoring and control of train position and running speed in subway systems, automatic control and flexible operation of escalators and elevators in subway systems, and security access control systems for subway stations. In automotive systems, magnetic sensors are used to sense the earth's magnetic field to determine the direction and position of the vehicle and provide accurate navigation information for the driver. Similarly, there are magnetic compasses used in navigation, magnetic heading instruments on aircraft, and speed, vibration and position information monitoring in high-speed railways. In the field of consumer electronics, magnetic sensors can be used in various smart wearable devices such as video game controllers, smart watches, smart phones and computers for motion detection and direction positioning. In medicine, magnetic sensors can be used to monitor the current and magnetic field of large equipment such as MRI and CT, and to monitor biological signals such as brain magnetism and muscle magnetism. In the field of non-destructive testing, magnetic sensors are used for consistency analysis of various conductive materials, such as aircraft skin testing, carbon fiber fracture detection, metal pipeline detection, and metal energy storage device detection.

[0004] There are two common three-axis magnetic field sensors in the current market: fluxgate type and chip type. Fluxgate sensors are large in size, usually discrete, and difficult to integrate into other systems. Chip-level magnetic field sensors face problems such as small bandwidth and low sensitivity. Among them, the sensitivity and response frequency of three-axis Hall sensors are very low, making it difficult to meet the increasingly high measurement needs. Due to problems with the manufacturing process, the z-axis of the three-axis tunnel magnetoresistive sensor is usually low in sensitivity, and it is easy to couple into magnetic fields in other directions, causing measurement errors. This leads to very limited applications of three-axis tunnel magnetoresistive sensors. Summary of the invention

[0005] The purpose of the present invention is to provide a direct-insertion three-axis wide-band magnetic field sensor, a preparation method and an application method to solve the above technical problems.

[0006] To achieve the above-mentioned purpose, the present invention provides a direct-insertion three-axis wide-band magnetic field sensor, comprising a horizontal substrate and a vertical substrate that are vertically plugged in, the horizontal substrate and the vertical substrate are arranged in an outer shell, the horizontal substrate is provided with a mutually perpendicular magnetic resistance coil combined Wheatstone full-bridge induction circuit for detecting magnetic fields in the X-axis and Y-axis directions, the horizontal substrate is provided with a jack, a welding disk is provided at the edge of the jack, a plug-in portion at the bottom of the vertical substrate is plugged in the jack and welded to the welding disk, and the vertical substrate is provided with a magnetic resistance coil combined Wheatstone full-bridge induction circuit for detecting the Z-axis direction.

[0007] Preferably, the magnetoresistor-coil combined Wheatstone full-bridge induction circuit comprises a Wheatstone full-bridge structure, a magnetoresistor and a coil. The magnetoresistor and the coil are respectively arranged on two bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetoresistor and the coil are consistent.

[0008] Preferably, the magnetoresistor-coil combined Wheatstone full-bridge induction circuit comprises a Wheatstone full-bridge structure, a magnetoresistor and a coil. The magnetoresistor and the coil are arranged on one of the bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetoresistor and the coil are consistent.

[0009] Preferably, the reluctance coil combined Wheatstone full-bridge induction circuit is connected to an instrument amplifier to achieve a single output.

[0010] Preferably, the magnetoresistive coil combined Wheatstone full-bridge induction circuit is connected to a differential output terminal to achieve differential output.

[0011] Preferably, the plug-in portion is provided with a welding plate, and the bottom of the vertical substrate is stepped.

[0012] A method for preparing the above-mentioned direct-insertion three-axis wide-band magnetic field sensor comprises the following specific steps:

[0013] Step S1: preparing a horizontal substrate and a vertical substrate;

[0014] Step S2: inserting the vertical substrate into the insertion hole of the horizontal substrate and fixing the connection by welding;

[0015] Step S3: After placing the output pins, the horizontal substrate and the vertical substrate, which are arranged perpendicular to each other, are placed into the outer shell, and are encapsulated by glue filling.

[0016] An application method of the above-mentioned direct-insertion three-axis wide-band magnetic field sensor, the specific process is as follows:

[0017] The magnetoresistive coil combined Wheatstone full-bridge induction circuit couples the magnetic field to be measured, changes the impedance of the magnetic resistance and the coil, and causes an unbalanced output of the magnetoresistive coil combined Wheatstone full-bridge induction circuit. The output voltage of the magnetoresistive coil combined Wheatstone full-bridge induction circuit is positively correlated with the magnetic field to be measured.

[0018] Preferably, at zero input, the bridge arm output is:

[0019]

[0020] Among them, X1, X2, X3 and X4 are the impedances of the components on the four bridge arms of the combined Wheatstone full-bridge induction circuit of the reluctance coil, and U is the supply voltage of the combined Wheatstone full-bridge induction circuit of the reluctance coil. When the impedances of the four components are the same, the output voltage difference V of the bridge arm is equal to 0. If a constant magnetic field is given, so that the impedances of the four components change by ΔX at the same time, and the total impedance of the bridge remains unchanged, and the impedances of the two bridge arms change in the opposite direction, then the output voltage should be:

[0021]

[0022] Since the impedance of the four components is the same, all X, then at this time:

[0023]

[0024] Simplified:

[0025]

[0026] Therefore, the present invention adopts the above-mentioned direct-insertion three-axis wide-band magnetic field sensor, preparation method and application method, which has the following beneficial effects:

[0027] (1) A Wheatstone full-bridge sensing circuit using a combined magnetoresistor coil includes a Wheatstone full-bridge structure, a magnetoresistor and a coil. The magnetoresistor and the coil are respectively arranged on two bridge arms of the Wheatstone full-bridge structure or on one of the bridge arms of the Wheatstone full-bridge structure. The measurement structure combining the magnetoresistor and the coil makes the sensor's sensitivity in the low frequency band dominated by the magnetoresistor, and the sensitivity in the high frequency band dominated by the coil, thereby expanding the sensor's magnetic field frequency measurement range. The impedance parameters of the magnetoresistor and the coil are consistent, avoiding the problem of low Z-axis signal-to-noise ratio caused by the limitation of the coating direction during chip-level packaging.

[0028] (2) The horizontal substrate and the vertical substrate are connected by vertical plugging and fixed by welding, so that the sensitive directions of the sensors are perpendicular to each other, thereby reducing the problem of strong Z-direction channel crosstalk introduced by the coating process during chip-level packaging. The discrete construction method reduces the size of the sensor. The size of the sensor of the present invention is only 15mm x 15mm x10mm.

[0029] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the horizontal substrate and the vertical substrate of the present invention;

[0031] Figure 2 It is a circuit principle diagram of the magnetic resistance coil combined Wheatstone full-bridge induction circuit of the present invention;

[0032] Figure 3 It is a schematic diagram of the horizontal substrate structure of the present invention;

[0033] Figure 4 This is a schematic diagram of the vertical substrate structure of the present invention;

[0034] Figure 5 It is a frequency response curve diagram within the passband of the present invention.

[0035] Reference numerals

[0036] 1. Horizontal substrate; 11. Socket; 2. Vertical substrate; 21. Plug-in portion; 3. Welding pad. DETAILED DESCRIPTION

[0037] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "installation", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0039] Example 1

[0040] like Figure 1As shown, a direct-insertion three-axis wide-band magnetic field sensor includes a horizontal substrate 1 and a vertical substrate 2 that are vertically plugged in. The horizontal substrate 1 and the vertical substrate 2 are arranged in an outer shell (not shown in the figure). A mutually perpendicular magnetoresistive coil combined Wheatstone full-bridge induction circuit is arranged on the horizontal substrate 1. The principle of the magnetoresistive coil combined Wheatstone full-bridge induction circuit is as follows: Figure 2 As shown, it is used to detect the magnetic field in the X-axis and Y-axis directions, such as Figure 3 As shown, the horizontal substrate 1 is provided with a socket 11, and a welding pad 3 is provided at the edge of the socket 11. The plug-in portion 21 at the bottom of the vertical substrate 2 is inserted into the socket 11 and welded to the welding pad 3. The plug-in portion 21 is provided with a welding pad 3. Figure 4 As shown, the bottom of the vertical substrate 2 is stepped, which is conducive to fixing the vertical substrate 2 and the horizontal substrate 1, while reducing the impact on the layout of components on the horizontal substrate 1. The vertical substrate 2 is provided with a magnetoresistive coil combined Wheatstone full-bridge induction circuit for detecting the Z-axis direction.

[0041] The magnetic resistance coil combined Wheatstone full-bridge induction circuit includes a Wheatstone full-bridge structure, a magnetic resistance and a coil. In this embodiment, the magnetic resistance and the coil are respectively arranged on the two bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetic resistance and the coil are consistent. The magnetic resistance coil combined Wheatstone full-bridge induction circuit is connected to an instrumentation amplifier to realize a single output. Alternatively, the magnetic resistance coil combined Wheatstone full-bridge induction circuit is connected to a differential output terminal to realize a differential output.

[0042] Example 2

[0043] The magnetoresistor coil combined Wheatstone full-bridge induction circuit comprises a Wheatstone full-bridge structure, a magnetoresistor and a coil. The magnetoresistor and the coil are arranged on one of the bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetoresistor and the coil are consistent.

[0044] A preparation method based on the above-mentioned direct-insertion three-axis wide-band magnetic field sensor, the specific steps are as follows:

[0045] Step S1: preparing a horizontal substrate 1 and a vertical substrate 2.

[0046] Step S2: insert the vertical substrate 2 into the insertion hole 11 of the horizontal substrate 1 and fix the connection by welding.

[0047] Step S3: After placing the output pins, the horizontal substrate 1 and the vertical substrate 2 which are arranged perpendicular to each other are placed into the outer shell, and are encapsulated by glue filling.

[0048] An application method based on the above-mentioned direct-insertion three-axis wide-band magnetic field sensor, a magnetoresistive coil combined Wheatstone full-bridge induction circuit couples the magnetic field to be measured, changes the impedance of the magnetoresistive coil and the coil, resulting in an unbalanced output of the magnetoresistive coil combined Wheatstone full-bridge induction circuit, and the output voltage of the magnetoresistive coil combined Wheatstone full-bridge induction circuit is positively correlated with the magnetic field to be measured.

[0049] At zero input, the bridge arm output is:

[0050]

[0051] Among them, X1, X2, X3 and X4 are the impedances of the components on the four bridge arms of the combined Wheatstone full-bridge induction circuit of the reluctance coil, and U is the supply voltage of the combined Wheatstone full-bridge induction circuit of the reluctance coil. When the impedances of the four components are the same, the output voltage difference V of the bridge arm is equal to 0. If a constant magnetic field is given, so that the impedances of the four components change by ΔX at the same time, and the total impedance of the bridge remains unchanged, and the impedances of the two bridge arms change in the opposite direction, then the output voltage should be:

[0052]

[0053] Since the impedance of the four components is the same, all X, then at this time:

[0054]

[0055] Simplified:

[0056]

[0057] The sensor made of the above structure is powered by ±5V, and the internal configuration forms a differential output. The Helmholtz coil is used to generate a DC-1MHz wide-frequency magnetic field of about 40uT. The sensor is used for frequency response testing. Its frequency response is as follows Figure 5 As shown in the figure, the final result is that within the range of DC-1MHz, the sensor sensitivity is not less than 20mV / V / uT.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A direct-insertion three-axis wide-band magnetic field sensor, characterized in that: The invention comprises a horizontal substrate and a vertical substrate which are vertically plugged in. The horizontal substrate and the vertical substrate are arranged in an outer shell. A Wheatstone full-bridge induction circuit with magnetoresistive coils perpendicular to each other is arranged on the horizontal substrate for detecting magnetic fields in the directions of the X-axis and the Y-axis. A socket is arranged on the horizontal substrate. A welding disk is arranged on the edge of the socket. A plug-in portion at the bottom of the vertical substrate is plugged in the socket and welded to the welding disk. A magnetoresistive coil combined Wheatstone full-bridge induction circuit for detecting the direction of the Z-axis is arranged on the vertical substrate.

2. The direct-insertion three-axis wide-band magnetic field sensor according to claim 1, characterized in that: The magnetic resistance coil combined Wheatstone full-bridge induction circuit comprises a Wheatstone full-bridge structure, wherein the magnetic resistance and the coil are respectively arranged on two bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetic resistance and the coil are consistent.

3. The direct-insertion three-axis wide-band magnetic field sensor according to claim 1, characterized in that: The magnetic resistance coil combined Wheatstone full-bridge induction circuit comprises a Wheatstone full-bridge structure, the magnetic resistance and the coil are arranged on one of the bridge arms of the Wheatstone full-bridge structure, and the impedance parameters of the magnetic resistance and the coil are consistent.

4. A direct-insertion three-axis wide-band magnetic field sensor according to claim 2 or 3, characterized in that: The reluctance coil combined Wheatstone full-bridge sensing circuit is connected with an instrumentation amplifier to achieve a single output.

5. The direct-insertion three-axis wide-band magnetic field sensor according to claim 2 or 3, characterized in that: The magnetoresistive coil combined Wheatstone full-bridge induction circuit is connected to a differential output terminal to realize differential output.

6. The direct-insertion three-axis wide-band magnetic field sensor according to claim 1, characterized in that: The plug-in part is provided with a welding plate, and the bottom of the vertical base plate is in a stepped shape.

7. A method for preparing a direct-insertion three-axis wide-band magnetic field sensor according to claim 1, characterized in that: The specific steps are as follows: Step S1: preparing a horizontal substrate and a vertical substrate; Step S2: inserting the vertical substrate into the insertion hole of the horizontal substrate and fixing the connection by welding; Step S3: After placing the output pins, the horizontal substrate and the vertical substrate, which are arranged perpendicular to each other, are placed into the outer shell, and are encapsulated by glue filling.

8. An application method of the direct-insertion three-axis wide-band magnetic field sensor according to claim 1, characterized in that: The specific process is as follows: The magnetoresistive coil combined Wheatstone full-bridge induction circuit couples the magnetic field to be measured, changes the impedance of the magnetic resistance and the coil, and causes an unbalanced output of the magnetoresistive coil combined Wheatstone full-bridge induction circuit. The output voltage of the magnetoresistive coil combined Wheatstone full-bridge induction circuit is positively correlated with the magnetic field to be measured.

9. The application method of the direct-insertion three-axis wide-band magnetic field sensor according to claim 8, characterized in that: At zero input, the bridge arm output is: Among them, X1, X2, X3 and X4 are the impedances of the components on the four bridge arms of the combined Wheatstone full-bridge induction circuit of the reluctance coil, and U is the supply voltage of the combined Wheatstone full-bridge induction circuit of the reluctance coil; when the impedances of the four components are the same, the output voltage difference V of the bridge arm is equal to 0. If a constant magnetic field is given, so that the impedances of the four components change by ΔX at the same time, and the total impedance of the bridge remains unchanged, and the impedances of the two bridge arms change in the opposite direction, then the output voltage should be: Since the impedance of the four components is the same, all X, then at this time: Simplified:

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