A signal conditioning circuit for a magnetic field monitoring sensor

Abstract

The application discloses a signal conditioning circuit of a magnetic field monitoring sensor, relates to the field of signal conditioning of a magnetic field monitoring sensor, and the signal conditioning circuit of the magnetic field monitoring sensor comprises a power module and a magnetic field signal processing module; the magnetic field signal processing module comprises a first sensing signal unit, a second sensing signal unit and a third sensing sensing signal unit; the first sensing signal unit, the second sensing signal unit and the third sensing signal unit measure the magnetic fields in X, Y and Z directions of a test environment respectively, and obtain final magnetic field signals; the application improves the magnetic field detection sensitivity, improves the magnetic field detection sensitivity, enhances the adaptability of the magnetic field sensor, and adapts to the induction of different magnetic field signals from a low frequency band to a high frequency band.

Description

Technical Field

[0001] This application relates to the field of signal conditioning for magnetic field monitoring sensors, and in particular to a signal conditioning circuit for a magnetic field monitoring sensor. Background Technology

[0002] With the increasing automation of J-ships, a large number of their electronic devices are used for communication, navigation, monitoring, diagnosis, and control, greatly improving the safety and operational efficiency of J-ship transportation. However, at the same time, various human and natural electromagnetic activities are highly concentrated, intertwined, and overlapping in certain time, spatial, and frequency domains, bringing about complex electromagnetic compatibility (EMC) problems. EMC problems are generally divided into conducted interference and radiated interference, requiring magnetic field sensors to detect spatial radiated interference signals. Radiated interference is mainly measured using non-contact methods. In near-field measurements, the electric field detection sensitivity of current magnetic field sensor signal processing circuits is relatively low. There is an urgent need for a signal conditioning circuit for a magnetic field monitoring sensor with high magnetic field detection sensitivity to enhance the adaptability of the magnetic field sensor and adapt to the sensing of different magnetic field signals from low to high frequency bands. Utility Model Content

[0003] The purpose of this application is to provide a signal conditioning circuit for a magnetic field monitoring sensor, which can improve the magnetic field detection sensitivity, enhance the adaptability of the magnetic field sensor, and adapt to the sensing of different magnetic field signals from low frequency band to high frequency band.

[0004] To achieve the above objectives, this application provides the following solution:

[0005] This application provides a signal conditioning circuit for a magnetic field monitoring sensor, including a power supply module and a magnetic field signal processing module; the magnetic field signal processing module includes a first sensing signal unit, a second sensing signal unit, and a third sensing signal unit; the first sensing signal unit, the second sensing signal unit, and the third sensing signal unit measure the magnetic field in the X, Y, and Z directions of the test environment, respectively, to obtain the final magnetic field signal.

[0006] Optionally, the first sensing signal unit includes a first RC filter circuit, a first large signal overvoltage protection circuit, and a first amplification subunit; the first RC filter circuit is used to filter the original magnetic field signal in the X direction of the test environment to obtain a first filtered magnetic field signal, and transmit the first filtered magnetic field signal to the first amplification subunit; the first amplification subunit is used to amplify the first filtered magnetic field signal to obtain a first amplified magnetic field signal.

[0007] Optionally, the second sensing signal unit includes a second RC filter circuit, a second large signal overvoltage protection circuit, and a second amplification subunit; the second RC filter circuit is used to filter the original magnetic field signal in the Y direction of the test environment to obtain a second filtered magnetic field signal, and transmit the second filtered magnetic field signal to the second amplification subunit; the second amplification subunit is used to amplify the second filtered magnetic field signal to obtain a second amplified magnetic field signal.

[0008] Optionally, the third sensing signal unit includes a third RC filter circuit, a third large signal overvoltage protection circuit, and a third amplification subunit; the third RC filter circuit is used to filter the original magnetic field signal in the Z direction of the test environment to obtain a third filtered magnetic field signal, and transmit the third filtered magnetic field signal to the third amplification subunit; the third amplification subunit is used to amplify the third filtered magnetic field signal to obtain a third amplified magnetic field signal.

[0009] Optionally, the first RC filter circuit includes a first through-hole capacitor, a second through-hole capacitor, a first resistor, a second resistor, a third resistor, and a first capacitor; one end of the first resistor is connected to one end of the first through-hole capacitor and one end of the second resistor, the other end of the first resistor is connected to one end of the second through-hole capacitor and one end of the third resistor, and the other ends of the second resistor and the third resistor are respectively connected to the two ends of the first capacitor.

[0010] The first large signal overvoltage protection circuit includes a first switching diode group and a second switching diode group; the first switching diode group includes a first diode and a second diode, and the second switching diode group includes a third diode and a fourth diode; the anode of the first diode is connected to the anode of the third diode, the cathode of the first diode is connected to the anode of the second diode, the cathode of the second diode is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; the first capacitor is also connected to the cathode of the first diode, the anode of the second diode, the cathode of the third diode, and the anode of the fourth diode;

[0011] The first amplification subunit includes a first amplifier, a fourth resistor, a fifth resistor, a second capacitor, and a third capacitor. The two ends of the fourth resistor are connected to the RG- and RG+ pins of the first amplifier, respectively. The other ends of the second and third resistors are also connected to the IN- and IN+ pins of the first amplifier, respectively. The VS+ pin of the first amplifier is connected to the reference voltage terminal, and the VS- pin of the first amplifier is grounded. The VREF pin of the first amplifier is connected to one end of the third capacitor and the target voltage terminal, and the other end of the third capacitor is grounded. The OUT pin of the first amplifier is connected to one end of the second capacitor, and the other end of the second capacitor is connected to one end of the fifth resistor and the output terminal of the first sensing signal unit, and the other end of the fifth resistor is grounded.

[0012] Optionally, the second RC filter circuit includes a third through-hole capacitor, a fourth through-hole capacitor, a sixth resistor, a seventh resistor, an eighth resistor, and a fourth capacitor; one end of the sixth resistor is connected to one end of the third through-hole capacitor and one end of the seventh resistor, the other end of the sixth resistor is connected to one end of the fourth through-hole capacitor and one end of the eighth resistor, and the other ends of the seventh resistor and the eighth resistor are respectively connected to the two ends of the fourth capacitor.

[0013] The second major signal overvoltage protection circuit includes a third switching diode group and a fourth switching diode group; the third switching diode group includes a fifth diode and a sixth diode, and the fourth switching diode group includes a seventh diode and an eighth diode; the anode of the fifth diode is connected to the anode of the seventh diode, the cathode of the fifth diode is connected to the anode of the sixth diode, the cathode of the sixth diode is connected to the cathode of the eighth diode, and the cathode of the seventh diode is connected to the anode of the eighth diode; the fourth capacitor is also connected to the cathode of the fifth diode, the anode of the sixth diode, the cathode of the seventh diode, and the anode of the eighth diode;

[0014] The second amplification subunit includes a second amplifier, a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor. The two ends of the ninth resistor are connected to the RG- and RG+ pins of the second amplifier, respectively. The other ends of the seventh and eighth resistors are also connected to the IN- and IN+ pins of the second amplifier, respectively. The VS+ pin of the second amplifier is connected to the reference voltage terminal, and the VS- pin of the second amplifier is grounded. The VREF pin of the second amplifier is connected to one end of the sixth capacitor and the target voltage terminal, and the other end of the sixth capacitor is grounded. The OUT pin of the second amplifier is connected to one end of the fifth capacitor, and the other end of the fifth capacitor is connected to one end of the tenth resistor and the output terminal of the second sensing signal unit, and the other end of the tenth resistor is grounded.

[0015] Optionally, the third RC filter circuit includes a fifth through-core capacitor, a sixth through-core capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a seventh capacitor; one end of the eleventh resistor is connected to one end of the fifth through-core capacitor and one end of the twelfth resistor, the other end of the eleventh resistor is connected to one end of the sixth through-core capacitor and one end of the thirteenth resistor, and the other ends of the twelfth resistor and the thirteenth resistor are respectively connected to the two ends of the seventh capacitor.

[0016] The third major signal overvoltage protection circuit includes a fifth switching diode group and a sixth switching diode group; the fifth switching diode group includes a ninth diode and a tenth diode, and the sixth switching diode group includes an eleventh diode and a twelfth diode; the anode of the ninth diode is connected to the anode of the eleventh diode, the cathode of the ninth diode is connected to the anode of the tenth diode, the cathode of the tenth diode is connected to the cathode of the twelfth diode, and the cathode of the eleventh diode is connected to the anode of the twelfth diode; the seventh capacitor is also connected to the cathode of the ninth diode, the anode of the tenth diode, the cathode of the eleventh diode, and the anode of the twelfth diode;

[0017] The third amplification subunit includes a third amplifier, a fourteenth resistor, a fifteenth resistor, and an eighth capacitor. The two ends of the fourteenth resistor are connected to the RG- and RG+ pins of the third amplifier, respectively. The other ends of the twelfth and thirteenth resistors are also connected to the IN- and IN+ pins of the third amplifier, respectively. The VS+ pin of the third amplifier is connected to the reference voltage terminal, and the VS- pin of the third amplifier is grounded. The VREF pin of the third amplifier is connected to the target voltage terminal. The OUT pin of the third amplifier is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is connected to one end of the fifteenth resistor and the output terminal of the third sensing signal unit. The other end of the fifteenth resistor is grounded.

[0018] Optionally, the power module includes a reference voltage conversion unit; the reference voltage conversion unit includes a thirteenth diode, a fourteenth diode, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, a first inductor, a second inductor, and a light-emitting diode;

[0019] The anode of the thirteenth diode is connected to the original power supply terminal. The cathode of the thirteenth diode is connected to one end of the eleventh capacitor, the cathode of the fourteenth diode, and one end of the first inductor. The other end of the eleventh capacitor is connected to ground. The anode of the fourteenth diode is connected to one end of the second inductor, and the cathode of the fourteenth diode is connected to one end of the first inductor. The other end of the first inductor is connected to one end of the twelfth capacitor, one end of the thirteenth capacitor, one end of the sixteenth resistor, one end of the fourteenth capacitor, one end of the fifteenth capacitor, one end of the sixteenth capacitor, one end of the seventeenth capacitor, and the reference voltage terminal. The other ends of the second inductor, the twelfth capacitor, and the thirteenth capacitor are connected to ground. The other end of the sixteenth resistor is connected to the anode of the LED, and the cathode of the LED is grounded. The other ends of the fourteenth, fifteenth, sixteenth, and seventeenth capacitors are connected and grounded.

[0020] Optionally, the power module includes a target voltage conversion unit; the target voltage conversion unit includes a seventeenth resistor, an eighteenth resistor, a ninth capacitor, a tenth capacitor, and a fourth amplifier; one end of the eighteenth resistor is connected to one end of the seventeenth resistor, one end of the ninth capacitor, and the positive input terminal of the fourth amplifier, and the other end of the eighteenth resistor is connected to a reference voltage terminal; the other end of the ninth capacitor is connected to the other end of the seventeenth resistor, the positive power supply terminal of the fourth amplifier, ground, and one end of the tenth capacitor; the negative input terminal of the fourth amplifier is connected to the output terminal of the fourth amplifier and the other end of the tenth capacitor; the positive power supply terminal of the fourth amplifier is connected to the reference voltage terminal, and the negative power supply terminal of the fourth amplifier is connected to the other end of the ninth capacitor, the other end of the seventeenth resistor, one end of the tenth capacitor, and ground; the output terminal of the fourth amplifier outputs the target voltage.

[0021] According to the specific embodiments provided in this application, the following technical effects are disclosed:

[0022] This application provides a signal conditioning circuit for a magnetic field monitoring sensor. The signal conditioning circuit includes a power supply module and a magnetic field signal processing module. The magnetic field signal processing module includes a first sensing signal unit, a second sensing signal unit, and a third sensing signal unit. The first sensing signal unit, the second sensing signal unit, and the third sensing signal unit measure the magnetic field in the X, Y, and Z directions of the test environment, respectively, to obtain the final magnetic field signal. This enables the measurement of magnetic fields in the X / Y / Z directions within a frequency range of 20Hz to 200kHz, thereby improving the magnetic field detection sensitivity, enhancing the adaptability of the magnetic field sensor, and adapting to the sensing of different magnetic field signals from low-frequency to high-frequency bands. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a structural diagram of a signal conditioning circuit for a magnetic field monitoring sensor provided in Embodiment 1 of this application.

[0025] Figure 2 This is a structural diagram of a magnetic field signal processing module provided in Embodiment 1 of this application.

[0026] Figure 3 This is a schematic diagram of the reference voltage conversion unit provided in Embodiment 1 of this application.

[0027] Figure 4This is a schematic diagram of the target voltage conversion unit provided in Embodiment 1 of this application.

[0028] Figure 5 This is a schematic diagram of the socket connection relationship provided in Embodiment 1 of this application.

[0029] Figure 6 This is a schematic diagram of the magnetic field monitoring sensor provided in Embodiment 1 of this application.

[0030] Figure 7 This is a block diagram of a magnetic field calibration system based on an excitation coil, as provided in Embodiment 1 of this application. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1.

[0034] like Figure 1 As shown, this embodiment provides a signal conditioning circuit for a magnetic field monitoring sensor, including a power supply module and a magnetic field signal processing module; the magnetic field signal processing module includes a first sensing signal unit, a second sensing signal unit, and a third sensing signal unit; the first sensing signal unit, the second sensing signal unit, and the third sensing signal unit measure the magnetic field in the X, Y, and Z directions of the test environment, respectively, to obtain the final magnetic field signal.

[0035] This embodiment uses the MS-II type magnetic field monitoring sensor to specifically describe the signal conditioning circuit of the magnetic field monitoring sensor. The MS-II type magnetic field monitoring sensor can measure the magnetic field in three directions (X / Y / Z) within the frequency range of 20Hz to 200kHz. The magnetic field strength and dynamic range requirements are shown in Table 1 below.

[0036] Table 1 shows the monitorable magnetic field strength and dynamic range.

[0037] 1 100Hz B~G ≥50dB 2 1kHz B~G ≥50dB 3 2kHz B~G ≥50dB 4 10kHz B~G ≥50dB 5 100kHz A~E ≥40dB

[0038] The MS-II type magnetic field monitoring sensor has the following interface and electrical characteristics: 1) Input voltage: +12VDC; 2) Power consumption: <1.5W; 3) Output impedance: 50Ω; 4) Connector: F104Z14J066-139 eight-pin aviation connector. The MS-II type magnetic field monitoring sensor has dimensions of <110mm×110mm×110mm and a weight of ≤2kg.

[0039] Magnetic field monitoring sensors utilize Faraday's law of electromagnetic induction to convert collected electromagnetic field signals into signals recognizable by the user system (MCU / AD). A schematic diagram of the magnetic field sensor principle is shown below. Figure 6 As shown.

[0040] Technical specifications of MS-II magnetic field monitoring sensor: a) Frequency range: low frequency 20Hz~100Hz, high frequency 100Hz~200kHz; b) Detectable magnetic field strength: B~G@100Hz~10kHz, dynamic range ≥50dB; A~E@200kHz, dynamic range ≥40dB.

[0041] A new mode for electromagnetic environment signal sensing: Real-time dynamic sensing of electromagnetic signal changes, with plug-and-play sensor nodes, strong scalability, and real-time secure transmission of sensed signal data. Traditional methods for sensing electromagnetic environment signals rely on integrated foreign instruments, which suffer from drawbacks such as large size, high cost, limited scalability, and inconvenience for system-level testing. This solution adopts an embedded design concept, enabling the system to meet the requirements of online testing, miniaturization, and complete domestic production.

[0042] The MS-II type magnetic field monitoring sensor needs to process electromagnetic field induction signals ranging from 20Hz to 200kHz, B to G, with a dynamic range ≥50dB. Based on the induction characteristics of the magnetic field antenna, the signal output from the antenna induction of magnetic field A at the low-frequency end is extremely weak, possibly only a few µV in extreme cases. However, at the high-frequency end, the magnetic field antenna outputs a larger signal for high-frequency, high-field-strength magnetic fields. Roughly estimated, the dynamic range of the magnetic field antenna output signal is approximately 4000 times greater than the dynamic range of the magnetic field strength. Low-frequency, weak field strength requires the front-end signal conditioning circuit to have an extremely low noise figure and high amplification gain, but high-frequency, strong field strength will directly cause the front-end signal conditioning circuit to prematurely enter saturation, losing its signal processing capability.

[0043] Therefore, the signal conditioning circuit design of the magnetic field monitoring sensor provided in this embodiment adopts a domestically produced broadband precision instrumentation amplifier with low noise, high gain, and large dynamic range. Since the magnetic field antenna is more sensitive to high-frequency magnetic fields, an RC filter circuit and a large-signal overvoltage protection circuit are added at the front end to avoid the influence of out-of-band high-frequency magnetic fields on the signal conditioning circuit.

[0044] The signal conditioning circuit of the magnetic field monitoring sensor includes three channels: XYZ, such as... Figure 2 As shown.

[0045] The first sensing signal unit includes a first RC filter circuit, a first large signal overvoltage protection circuit, and a first amplification subunit; the first RC filter circuit is used to filter the original magnetic field signal in the X direction of the test environment to obtain a first filtered magnetic field signal, and transmit the first filtered magnetic field signal to the first amplification subunit; the first amplification subunit is used to amplify the first filtered magnetic field signal to obtain a first amplified magnetic field signal.

[0046] Figure 2 The signal conditioning circuit in the image is the main conditioning circuit. Based on the induction characteristics of the magnetic field antenna, at low frequencies, the signal induced by the antenna in a 70dBpT magnetic field is extremely weak, possibly only a few µV in extreme cases. However, at high frequencies, the signal induced by the magnetic field antenna in high-frequency, high-field-strength magnetic fields is much larger. Roughly estimated, the dynamic range of the magnetic field antenna's output signal is approximately 4000 times greater than the dynamic range of the magnetic field strength. Low-frequency, weak field strength requires the front-end signal conditioning circuit to have an extremely low noise figure and high amplification gain, but high-frequency, strong field strength will directly cause the front-end signal conditioning circuit to enter saturation prematurely, losing its signal processing capability.

[0047] Therefore, the signal conditioning circuit design for the magnetic field sensor utilizes a domestically produced, low-noise, high-gain, and wide dynamic range broadband precision instrumentation amplifier. Since the magnetic field antenna is more sensitive to high-frequency magnetic fields, an RC filter circuit and a large-signal overvoltage protection circuit were added at the front end to avoid the influence of out-of-band high-frequency magnetic fields on the signal conditioning circuit.

[0048] The first RC filter circuit includes a first through-hole capacitor Z1, a second through-hole capacitor Z2, a first resistor R1, a second resistor R2, a third resistor R3, and a first capacitor C1. One end of the first resistor R1 is connected to one end of the first through-hole capacitor Z1 and one end of the second resistor R2, and the other end of the first resistor R1 is connected to one end of the second through-hole capacitor Z2 and one end of the third resistor R3. The other ends of the second resistor R2 and the third resistor R3 are respectively connected to the two ends of the first capacitor C1.

[0049] The first large signal overvoltage protection circuit includes a first switching diode group and a second switching diode group; the first switching diode group includes a first diode D1 and a second diode D2, and the second switching diode group includes a third diode D3 and a fourth diode D4; the anode of the first diode D1 is connected to the anode of the third diode D3, the cathode of the first diode D1 is connected to the anode of the second diode D2, the cathode of the second diode D2 is connected to the cathode of the fourth diode D4, and the cathode of the third diode D3 is connected to the anode of the fourth diode D4; the first capacitor is also connected to the cathode of the first diode D1, the anode of the second diode D2, the cathode of the third diode D3, and the anode of the fourth diode D4.

[0050] The first amplification subunit includes a first amplifier U1, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and a third capacitor C3. The two ends of the fourth resistor R4 are connected to the RG- and RG+ pins of the first amplifier U1, respectively. The other ends of the second resistor R2 and the third resistor are also connected to the IN- and IN+ pins of the first amplifier U1, respectively. The VS+ pin of the first amplifier U1 is connected to the reference voltage terminal VS+, and the VS- pin of the first amplifier U1 is grounded. The VREF pin of the first amplifier U1 is connected to one end of the third capacitor C3 and the target voltage terminal VC, and the other end of the third capacitor C3 is grounded. The OUT pin of the first amplifier U1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to one end of the fifth resistor R5 and the output terminal of the first sensing signal unit, and the other end of the fifth resistor R5 is grounded.

[0051] The second sensing signal unit includes a second RC filter circuit, a second large signal overvoltage protection circuit, and a second amplification subunit. The second RC filter circuit is used to filter the original magnetic field signal in the Y direction of the test environment to obtain a second filtered magnetic field signal, and transmit the second filtered magnetic field signal to the second amplification subunit. The second amplification subunit is used to amplify the second filtered magnetic field signal to obtain a second amplified magnetic field signal.

[0052] The second RC filter circuit includes a third through-core capacitor Z3, a fourth through-core capacitor Z4, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, and a fourth capacitor C4; one end of the sixth resistor R6 is connected to one end of the third through-core capacitor Z3 and one end of the seventh resistor R7, the other end of the sixth resistor R6 is connected to one end of the fourth through-core capacitor Z4 and one end of the eighth resistor R8, and the other ends of the seventh resistor R7 and the eighth resistor R8 are respectively connected to the two ends of the fourth capacitor C4;

[0053] The second major signal overvoltage protection circuit includes a third switching diode group and a fourth switching diode group; the third switching diode group includes a fifth diode D5 and a sixth diode D6, and the fourth switching diode group includes a seventh diode D7 and an eighth diode D8; the anode of the fifth diode D5 is connected to the anode of the seventh diode D7, the cathode of the fifth diode D5 is connected to the anode of the sixth diode D6, the cathode of the sixth diode D6 is connected to the cathode of the eighth diode D8, and the cathode of the seventh diode D7 is connected to the anode of the eighth diode D8; the fourth capacitor C4 is also connected to the cathode of the fifth diode D5, the anode of the sixth diode D6, the cathode of the seventh diode D7, and the anode of the eighth diode D8;

[0054] The second amplification subunit includes a second amplifier U2, a ninth resistor R9, a tenth resistor R10, a fifth capacitor C5, and a sixth capacitor C6. The two ends of the ninth resistor R9 are connected to the RG- and RG+ pins of the second amplifier U2, respectively. The other ends of the seventh resistor R7 and the eighth resistor R8 are also connected to the IN- and IN+ pins of the second amplifier U2, respectively. The VS+ pin of the second amplifier U2 is connected to the reference voltage terminal VS+, and the VS- pin of the second amplifier U2 is grounded. The VREF pin of the second amplifier U2 is connected to one end of the sixth capacitor C6 and the target voltage terminal VC, and the other end of the sixth capacitor C6 is grounded. The OUT pin of the second amplifier U2 is connected to one end of the fifth capacitor C5, and the other end of the fifth capacitor C5 is connected to one end of the tenth resistor R10 and the output terminal of the second sensing signal unit. The other end of the tenth resistor R10 is grounded.

[0055] The third sensing signal unit includes a third RC filter circuit, a third large signal overvoltage protection circuit, and a third amplification subunit. The third RC filter circuit is used to filter the original magnetic field signal in the Z direction of the test environment to obtain a third filtered magnetic field signal, and transmit the third filtered magnetic field signal to the third amplification subunit. The third amplification subunit is used to amplify the third filtered magnetic field signal to obtain a third amplified magnetic field signal.

[0056] The third RC filter circuit includes a fifth through-core capacitor Z5, a sixth through-core capacitor Z6, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a seventh capacitor C7. One end of the eleventh resistor R11 is connected to one end of the fifth through-core capacitor Z5 and one end of the twelfth resistor R12, and the other end of the eleventh resistor R11 is connected to one end of the sixth through-core capacitor Z6 and one end of the thirteenth resistor R13. The other ends of the twelfth resistor R12 and the thirteenth resistor R13 are respectively connected to the two ends of the seventh capacitor C7.

[0057] The third major signal overvoltage protection circuit includes a fifth switching diode group and a sixth switching diode group; the fifth switching diode group includes a ninth diode D9 and a tenth diode D10, and the sixth switching diode group includes an eleventh diode D11 and a twelfth diode D12; the anode of the ninth diode D9 is connected to the anode of the eleventh diode D11, the cathode of the ninth diode D9 is connected to the anode of the tenth diode D10, the cathode of the tenth diode D10 is connected to the cathode of the twelfth diode D12, and the cathode of the eleventh diode D11 is connected to the anode of the twelfth diode D12; the seventh capacitor C7 is also connected to the cathode of the ninth diode D9, the anode of the tenth diode D10, the cathode of the eleventh diode D11, and the anode of the twelfth diode D12;

[0058] The third amplification subunit includes a third amplifier U3, a fourteenth resistor R14, a fifteenth resistor R15, and an eighth capacitor C8. The two ends of the fourteenth resistor R14 are connected to the RG- and RG+ pins of the third amplifier U3, respectively. The other ends of the twelfth resistor R12 and the thirteenth resistor R13 are also connected to the IN- and IN+ pins of the third amplifier U3, respectively. The VS+ pin of the third amplifier U3 is connected to the reference voltage terminal VS+, and the VS- pin of the third amplifier U3 is grounded. The VREF pin of the third amplifier U3 is connected to the target voltage terminal VC. The OUT pin of the third amplifier U3 is connected to one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is connected to one end of the fifteenth resistor R15 and the output terminal of the third sensing signal unit. The other end of the fifteenth resistor R15 is grounded.

[0059] The VREF pins of the first amplifier U1, the second amplifier U2, and the third amplifier U3 are connected together and connected to the target voltage terminal VC.

[0060] The power module includes a reference voltage conversion unit; such as Figure 3 As shown, the reference voltage conversion unit provides a good power supply for the signal conditioning circuit and is designed with input overvoltage, reverse connection protection, high frequency filter and power-on indicator.

[0061] The reference voltage conversion unit includes a thirteenth diode D13, a fourteenth diode D14, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a sixteenth capacitor C16, a seventeenth capacitor C17, a first inductor L1, a second inductor L2, and a light-emitting diode LED1.

[0062] The anode of the thirteenth diode D13 is connected to the original power supply terminal DC. The cathode of the thirteenth diode D13 is connected to one end of the eleventh capacitor C11, the cathode of the fourteenth diode D14, and one end of the first inductor L1. The other end of the eleventh capacitor C11 is connected to ground. The anode of the fourteenth diode D14 is connected to one end of the second inductor L2, and the cathode of the fourteenth diode D14 is connected to one end of the first inductor L1. The other end of the first inductor L1 is connected to one end of the twelfth capacitor C12, one end of the thirteenth capacitor C13, and the sixteenth resistor R16. One end of the fourteenth capacitor C14, one end of the fifteenth capacitor C15, one end of the sixteenth capacitor C16, one end of the seventeenth capacitor C17, and the reference voltage terminal VS+ are connected; the other end of the second inductor L2, the other end of the twelfth capacitor C12, and the other end of the thirteenth capacitor C13 are connected to ground; the other end of the sixteenth resistor R16 is connected to the positive terminal of the light-emitting diode LED1, and the negative terminal of the light-emitting diode LED1 is grounded; the other ends of the fourteenth capacitor C14, the other ends of the fifteenth capacitor C15, the other ends of the sixteenth capacitor C16, and the other ends of the seventeenth capacitor C17 are connected and grounded.

[0063] The power module includes a target voltage conversion unit; such as Figure 4 As shown, the target voltage conversion unit includes a seventeenth resistor R17, an eighteenth resistor R18, a ninth capacitor C9, a tenth capacitor C10, and a fourth amplifier U4. One end of the eighteenth resistor R18 is connected to one end of the seventeenth resistor R17, one end of the ninth capacitor C9, and the positive input terminal of the fourth amplifier U4. The other end of the eighteenth resistor R18 is connected to the reference voltage terminal VS+. The other end of the ninth capacitor C9 is connected to the other end of the seventeenth resistor R17, the positive power supply terminal of the fourth amplifier U4, ground, and one end of the tenth capacitor C10. The negative input terminal of the fourth amplifier U4 is connected to the output terminal of the fourth amplifier U4 and the other end of the tenth capacitor C10. The positive power supply terminal of the fourth amplifier U4 is connected to the reference voltage terminal VS+. The negative power supply terminal of the fourth amplifier U4 is connected to the other end of the ninth capacitor C9, the other end of the seventeenth resistor R17, one end of the tenth capacitor C10, and ground. The output terminal of the fourth amplifier U4 outputs the target voltage. Figure 4 The power supply module in the circuit is a reference voltage generation circuit, which provides a reference voltage for the precision instrumentation amplifier.

[0064] The connection relationship of socket J1 is as follows Figure 5 As shown, the connector pin definitions are illustrated. The left-hand interface of socket J1 connects to the original power supply (DC), the output of the first sensing signal unit, the output of the second sensing signal unit, and the output of the third sensing signal unit, respectively. The voltage of the original power supply (DC) is 12V. Socket J1 is a (CON-JL24-8ZJB)JL24 type socket.

[0065] The capacitors C1, C4, and C7 are all 1000pF, 25V. The capacitors C3, C6, C9, C14-C17 are all 100nF, 25V. The thirteenth capacitor, C13, is also 100nF, 25V. The capacitors C2, C5, C8, and C10 are all 10uF, 25V. The capacitors C11 and C12 are both 10uF, 26V. The LED1 is NCD0603R1. The resistors R16, R17, and R18 are all 10KΩ, 5%. The resistors R4, R9, and R14 are all 12.7KΩ, 1%. The resistors R2, R3, R5, R7, R8, R10, R12, R13, and R15 are all 3KΩ, 1%. The first amplifier U1, the second amplifier U2, and the third amplifier U3 can be either a TPA1286U precision instrumentation amplifier or an SGM621 amplifier. The fourth amplifier U4 can be an RS8411 operational amplifier. The fourteenth diode is a TVS diode (Transient Voltage Suppression diode).

[0066] To improve component reliability and extend product lifespan, the impact of applied stress and temperature on components is reduced during circuit design to ensure reliable circuit operation. Different derating methods are applied to different components. Class I derating is used for conventional components such as resistors and capacitors.

[0067] Magnetic field calibration system based on excitation coil, such as Figure 7 As shown, this magnetic field calibration system uses an excitation coil as a magnetic field generator to establish the required standard magnetic field inside the coil. This standard field is then used to calibrate the frequency response and linearity characteristics of the magnetic field sensor. The signal generated by the system's signal generator is amplified by a power amplifier and then passed through a series sampling resistor (i.e.,...). Figure 7 A precision resistor is connected to an excitation coil device (the excitation coil device is a magnetic field loop). A first spectrum analyzer and a second spectrum analyzer are connected to the sampling resistor end. The measured voltage is converted into the current flowing through the coil. Based on the geometric parameters of the coil, the number of coil housings, and the measured current, the magnetic field strength on the central axis of the coil can be accurately calculated.

[0068] The MS-II magnetic field monitoring sensor has the following functions: it can measure the magnetic field in the X, Y, and Z directions of the environment. It features X, Y, and Z direction sensing signal units, and its performance characteristics have been verified through simulation and actual testing. Magnetic field sensor specifications: a) Magnetic field strength range B to G can be monitored within the frequency range of 100Hz to 10kHz, with a dynamic range ≥50dB; b) Magnetic field strength range A to E can be monitored within the frequency range of 200kHz, with a dynamic range ≥40dB. These performance characteristics have been verified through simulation and actual testing.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A signal conditioning circuit for a magnetic field monitoring sensor, characterized in that, The signal conditioning circuit of the magnetic field monitoring sensor includes a power supply module and a magnetic field signal processing module; the magnetic field signal processing module includes a first sensing signal unit, a second sensing signal unit, and a third sensing signal unit; the first sensing signal unit, the second sensing signal unit, and the third sensing signal unit measure the magnetic field in the X, Y, and Z directions of the test environment, respectively, to obtain the final magnetic field signal.

2. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 1, characterized in that, The first sensing signal unit includes a first RC filter circuit, a first large signal overvoltage protection circuit, and a first amplification subunit; the first RC filter circuit is used to filter the original magnetic field signal in the X direction of the test environment to obtain a first filtered magnetic field signal, and transmit the first filtered magnetic field signal to the first amplification subunit; the first amplification subunit is used to amplify the first filtered magnetic field signal to obtain a first amplified magnetic field signal.

3. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 1, characterized in that, The second sensing signal unit includes a second RC filter circuit, a second large signal overvoltage protection circuit, and a second amplification subunit; the second RC filter circuit is used to filter the original magnetic field signal in the Y direction of the test environment to obtain a second filtered magnetic field signal, and transmit the second filtered magnetic field signal to the second amplification subunit; the second amplification subunit is used to amplify the second filtered magnetic field signal to obtain a second amplified magnetic field signal.

4. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 1, characterized in that, The third sensing signal unit includes a third RC filter circuit, a third large signal overvoltage protection circuit, and a third amplification subunit. The third RC filter circuit is used to filter the original magnetic field signal in the Z direction of the test environment to obtain a third filtered magnetic field signal, and transmit the third filtered magnetic field signal to the third amplification subunit. The third amplification subunit is used to amplify the third filtered magnetic field signal to obtain a third amplified magnetic field signal.

5. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 2, characterized in that, The first RC filter circuit includes a first through-hole capacitor, a second through-hole capacitor, a first resistor, a second resistor, a third resistor, and a first capacitor; one end of the first resistor is connected to one end of the first through-hole capacitor and one end of the second resistor, the other end of the first resistor is connected to one end of the second through-hole capacitor and one end of the third resistor, and the other ends of the second resistor and the third resistor are respectively connected to the two ends of the first capacitor. The first large signal overvoltage protection circuit includes a first switching diode group and a second switching diode group; the first switching diode group includes a first diode and a second diode, and the second switching diode group includes a third diode and a fourth diode; the anode of the first diode is connected to the anode of the third diode, the cathode of the first diode is connected to the anode of the second diode, the cathode of the second diode is connected to the cathode of the fourth diode, and the cathode of the third diode is connected to the anode of the fourth diode; the first capacitor is also connected to the cathode of the first diode, the anode of the second diode, the cathode of the third diode, and the anode of the fourth diode; The first amplification subunit includes a first amplifier, a fourth resistor, a fifth resistor, a second capacitor, and a third capacitor. The two ends of the fourth resistor are connected to the RG- and RG+ pins of the first amplifier, respectively. The other ends of the second and third resistors are also connected to the IN- and IN+ pins of the first amplifier, respectively. The VS+ pin of the first amplifier is connected to the reference voltage terminal, and the VS- pin of the first amplifier is grounded. The VREF pin of the first amplifier is connected to one end of the third capacitor and the target voltage terminal, and the other end of the third capacitor is grounded. The OUT pin of the first amplifier is connected to one end of the second capacitor, and the other end of the second capacitor is connected to one end of the fifth resistor and the output terminal of the first sensing signal unit, and the other end of the fifth resistor is grounded.

6. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 3, characterized in that, The second RC filter circuit includes a third through-core capacitor, a fourth through-core capacitor, a sixth resistor, a seventh resistor, an eighth resistor, and a fourth capacitor; one end of the sixth resistor is connected to one end of the third through-core capacitor and one end of the seventh resistor, the other end of the sixth resistor is connected to one end of the fourth through-core capacitor and one end of the eighth resistor, and the other ends of the seventh resistor and the eighth resistor are respectively connected to the two ends of the fourth capacitor. The second major signal overvoltage protection circuit includes a third switching diode group and a fourth switching diode group; the third switching diode group includes a fifth diode and a sixth diode, and the fourth switching diode group includes a seventh diode and an eighth diode; the anode of the fifth diode is connected to the anode of the seventh diode, the cathode of the fifth diode is connected to the anode of the sixth diode, the cathode of the sixth diode is connected to the cathode of the eighth diode, and the cathode of the seventh diode is connected to the anode of the eighth diode; the fourth capacitor is also connected to the cathode of the fifth diode, the anode of the sixth diode, the cathode of the seventh diode, and the anode of the eighth diode; The second amplification subunit includes a second amplifier, a ninth resistor, a tenth resistor, a fifth capacitor, and a sixth capacitor. The two ends of the ninth resistor are connected to the RG- and RG+ pins of the second amplifier, respectively. The other ends of the seventh and eighth resistors are also connected to the IN- and IN+ pins of the second amplifier, respectively. The VS+ pin of the second amplifier is connected to the reference voltage terminal, and the VS- pin of the second amplifier is grounded. The VREF pin of the second amplifier is connected to one end of the sixth capacitor and the target voltage terminal, and the other end of the sixth capacitor is grounded. The OUT pin of the second amplifier is connected to one end of the fifth capacitor, and the other end of the fifth capacitor is connected to one end of the tenth resistor and the output terminal of the second sensing signal unit, and the other end of the tenth resistor is grounded.

7. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 4, characterized in that, The third RC filter circuit includes a fifth through-core capacitor, a sixth through-core capacitor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, and a seventh capacitor; one end of the eleventh resistor is connected to one end of the fifth through-core capacitor and one end of the twelfth resistor, the other end of the eleventh resistor is connected to one end of the sixth through-core capacitor and one end of the thirteenth resistor, and the other ends of the twelfth and thirteenth resistors are respectively connected to the two ends of the seventh capacitor. The third major signal overvoltage protection circuit includes a fifth switching diode group and a sixth switching diode group; the fifth switching diode group includes a ninth diode and a tenth diode, and the sixth switching diode group includes an eleventh diode and a twelfth diode; the anode of the ninth diode is connected to the anode of the eleventh diode, the cathode of the ninth diode is connected to the anode of the tenth diode, the cathode of the tenth diode is connected to the cathode of the twelfth diode, and the cathode of the eleventh diode is connected to the anode of the twelfth diode; the seventh capacitor is also connected to the cathode of the ninth diode, the anode of the tenth diode, the cathode of the eleventh diode, and the anode of the twelfth diode; The third amplification subunit includes a third amplifier, a fourteenth resistor, a fifteenth resistor, and an eighth capacitor. The two ends of the fourteenth resistor are connected to the RG- and RG+ pins of the third amplifier, respectively. The other ends of the twelfth and thirteenth resistors are also connected to the IN- and IN+ pins of the third amplifier, respectively. The VS+ pin of the third amplifier is connected to the reference voltage terminal, and the VS- pin of the third amplifier is grounded. The VREF pin of the third amplifier is connected to the target voltage terminal. The OUT pin of the third amplifier is connected to one end of the eighth capacitor, and the other end of the eighth capacitor is connected to one end of the fifteenth resistor and the output terminal of the third sensing signal unit. The other end of the fifteenth resistor is grounded.

8. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 7, characterized in that, The power module includes a reference voltage conversion unit; the reference voltage conversion unit includes a thirteenth diode, a fourteenth diode, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, a first inductor, a second inductor, and a light-emitting diode; The anode of the thirteenth diode is connected to the original power supply terminal. The cathode of the thirteenth diode is connected to one end of the eleventh capacitor, the cathode of the fourteenth diode, and one end of the first inductor. The other end of the eleventh capacitor is connected to ground. The anode of the fourteenth diode is connected to one end of the second inductor, and the cathode of the fourteenth diode is connected to one end of the first inductor. The other end of the first inductor is connected to one end of the twelfth capacitor, one end of the thirteenth capacitor, one end of the sixteenth resistor, one end of the fourteenth capacitor, one end of the fifteenth capacitor, one end of the sixteenth capacitor, one end of the seventeenth capacitor, and the reference voltage terminal. The other ends of the second inductor, the twelfth capacitor, and the thirteenth capacitor are connected to ground. The other end of the sixteenth resistor is connected to the anode of the LED, and the cathode of the LED is grounded. The other ends of the fourteenth, fifteenth, sixteenth, and seventeenth capacitors are connected and grounded.

9. The signal conditioning circuit of the magnetic field monitoring sensor according to claim 8, characterized in that, The power module includes a target voltage conversion unit; the target voltage conversion unit includes a seventeenth resistor, an eighteenth resistor, a ninth capacitor, a tenth capacitor, and a fourth amplifier; one end of the eighteenth resistor is connected to one end of the seventeenth resistor, one end of the nineth capacitor, and the positive input terminal of the fourth amplifier, and the other end of the eighteenth resistor is connected to a reference voltage terminal; The other end of the ninth capacitor is connected to the other end of the seventeenth resistor, the positive power supply terminal of the fourth amplifier, ground, and one end of the tenth capacitor; the negative input terminal of the fourth amplifier is connected to the output terminal of the fourth amplifier and the other end of the tenth capacitor; the positive power supply terminal of the fourth amplifier is connected to the reference voltage terminal, and the negative power supply terminal of the fourth amplifier is connected to the other end of the ninth capacitor, the other end of the seventeenth resistor, one end of the tenth capacitor, and ground; the output terminal of the fourth amplifier outputs the target voltage.

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