Current measuring device

Abstract

The application relates to a current measuring device. The current measuring device comprises a power supply interface, a sampling resistance module, a current transmitting module, a Hall effect current sensing module, a giant magnetoresistance effect current sensing module, a tunnel magnetoresistance effect measuring module and a magnetic flux gate current sensor module; the current measuring device is connected with an external power supply through the power supply interface. The method can meet the requirement of comprehensive comparison of different current detection methods in teaching demand.

Description

Technical Field

[0001] This application relates to the field of measurement technology, and in particular to a current measuring device. Background Technology

[0002] In today's rapidly evolving technological landscape, current detection, as a fundamental component of electronics, plays a crucial role in various engineering applications and scientific research. However, traditional current detection experimental devices suffer from a series of limitations, including bulky size, cumbersome operating procedures, and insufficient adaptability. This presents a significant challenge, particularly for training users to apply current detection technology in real-world projects.

[0003] Currently, several current measurement devices have been proposed, including portable resistance current detectors, high-safety multimeters for current detection experiments, and multifunctional voltmeters for physics experiments, to efficiently train users on their mastery of current detection technology.

[0004] However, the above methods cannot meet the requirements of teaching for a comprehensive comparison of different current detection methods. Summary of the Invention

[0005] Therefore, it is necessary to provide a current measuring device that can meet the needs of teaching and make comprehensive comparisons of different current detection methods, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a current measuring device, comprising:

[0007] The device includes a power interface, a sampling resistor module, a current transmitter module, a Hall effect current sensing module, a giant magnetoresistive effect current sensing module, a tunnel magnetoresistive effect measurement module, and a fluxgate current sensor module. The current measuring device is connected to an external power supply via the power interface.

[0008] A sampling resistor module is used to form an ohmic circuit and a first measurement terminal is provided on the ohmic circuit; the first measurement terminal is used to provide a test port for the user to test the first current signal of the branch on the ohmic circuit;

[0009] The current transmitter module is used to form a current conversion circuit, and a second test terminal is provided on the current conversion circuit; the second test terminal is used to provide users with a test port to test the second current signal of the branch on the current conversion circuit;

[0010] The Hall effect current sensing module is used to form a Hall circuit, and a third test terminal is provided on the Hall circuit; the third test terminal is used to provide the user with a signal port to test the third current signal of the branch on the Hall circuit;

[0011] The giant magnetoresistive effect current sensing module is used to form a giant magnetoresistive circuit, and a fourth test terminal is provided on the giant magnetoresistive circuit; the fourth test terminal is used to provide the user with a signal port to test the fourth current signal of the branch on the giant magnetoresistive circuit;

[0012] The tunnel magnetoresistive effect measurement module is used to form a tunnel magnetoresistive circuit and has a fifth test terminal on the tunnel magnetoresistive circuit. The fifth test terminal is used to provide the user with a signal port to test the fifth current signal of the branch on the tunnel magnetoresistive circuit.

[0013] The fluxgate current sensor module is used to form a fluxgate circuit and has a sixth test terminal on the fluxgate circuit. The sixth test terminal is used to provide the user with a signal port to test the sixth current signal of the branch on the fluxgate circuit.

[0014] In one embodiment, the sampling resistor module includes a resistor assembly, a socket assembly, a resistor input terminal, a resistor output terminal, a chip input terminal, and a chip output terminal.

[0015] The resistor assembly is connected to both the resistor input terminal and the resistor output terminal.

[0016] The socket assembly is connected to the chip input terminal and the chip output terminal, respectively;

[0017] A socket assembly used to amplify the current signal output by a current measuring device.

[0018] In one embodiment, the resistor assembly includes a plurality of first resistor elements with different resistance values;

[0019] The socket assembly includes a chip socket assembly and a resistor pin assembly. The chip socket assembly is used to connect chips with different package types, and the resistor pin assembly is used to connect second resistor elements with different resistance values. The second resistor elements are used to cooperate with the chip to output a current signal that meets the requirements.

[0020] In one embodiment, the current transmitter module includes a resistor input terminal, a first power input terminal, a first ground terminal, and a current transmitter.

[0021] A current transmitter includes an input signal isolation circuit, a current conversion circuit, and an output circuit.

[0022] In one embodiment, the current transmitter is model SIN-SDJI-5A, the current measurement range of the current transmitter is 0-5A, the output current range of the current transmitter is 4-20mA, and the operating power supply of the current transmitter is 24VDC.

[0023] In one embodiment, the Hall effect current sensing module includes a sensor chip, a first voltage output terminal, a second power supply input terminal, a second ground terminal, and a circuit under test input interface.

[0024] The sensor chip model is ACS712, the current measurement range of the sensor chip is ±5A, and the frequency range of the sensor chip is 0-80kHz.

[0025] In one embodiment, the giant magnetoresistive effect current sensing module includes a giant magnetoresistive chip, a third power supply input terminal, a third grounding terminal, a current output terminal, a second voltage output terminal, and a circuit under test input interface.

[0026] The giant magnetoresistive chip is the ACS70331 model. The current detection range of the giant magnetoresistive chip is ±2.5A, the frequency range is 0-1MHz, the operating temperature range is -20°C - 85°C, and the sensitivity is 200mV / A.

[0027] In one embodiment, the tunnel magnetoresistive effect measurement module includes a fourth power input terminal, a fourth ground terminal, a third voltage output terminal, and multiple first current sensors with different ranges.

[0028] The first current sensor includes a current-perforated hole, which is used to penetrate the object to be measured.

[0029] The first current sensor is a TMR7401 current sensor. The power supply voltage of the first current sensor is 5V, and the rated output voltage of the first current sensor is 3.7V.

[0030] In one embodiment, the fluxgate current sensor module includes a measured current input terminal, a measured current output terminal, a fifth power supply input terminal, a fifth ground terminal, a fourth voltage output terminal, and multiple second current sensors with different ranges.

[0031] The current and voltage relationships differ for second current sensors with different ranges.

[0032] In one embodiment, the power interface, sampling resistor module, current transmitter module, Hall effect current sensing module, giant magnetoresistive effect current sensing module, tunnel magnetoresistive effect measurement module, and fluxgate current sensor module all support a variety of different connection methods.

[0033] The aforementioned current measuring device includes: a power interface, a sampling resistor module, a current transmitter module, a Hall effect current sensing module, a giant magnetoresistive effect current sensing module, a tunneling magnetoresistive effect measurement module, and a fluxgate current sensor module. The current measuring device is connected to an external power source via the power interface. The sampling resistor module forms an ohmic circuit and has a first measurement terminal on it. The first measurement terminal provides a test port for the user to test the first current signal of a branch in the ohmic circuit. The current transmitter module forms a current conversion circuit and has a second test terminal on it. The second test terminal provides a test port for the user to test the second current signal of a branch in the current conversion circuit. The Hall effect current sensing module forms a Hall circuit and has a third test terminal on it. The system comprises the following terminals: a third test terminal for providing a signal port for testing the third current signal of a branch on the Hall circuit; a giant magnetoresistive effect current sensing module for forming a giant magnetoresistive circuit, with a fourth test terminal on the circuit; a tunneling magnetoresistive effect measurement module for forming a tunneling magnetoresistive circuit, with a fifth test terminal on the circuit; a fluxgate current sensor module for forming a fluxgate current circuit, with a sixth test terminal on the circuit; and a fluxgate current sensor module for providing a signal port for testing the sixth current signal of a branch on the fluxgate current circuit. This method meets the requirement for comprehensive comparison of different current detection methods in teaching. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a diagram illustrating the application environment of the current measuring device in one embodiment;

[0036] Figure 2 This is a schematic diagram of a current measuring device in one embodiment;

[0037] Figure 3 This is a schematic diagram of a sampling resistor module in one embodiment;

[0038] Figure 4 This is a schematic diagram of a socket assembly in one embodiment;

[0039] Figure 5 This is a schematic diagram showing the low-end placement of the sampling resistor in one embodiment;

[0040] Figure 6 This is a schematic diagram showing the sampling resistor placed at its high end in one embodiment;

[0041] Figure 7 This is a schematic diagram of a current transmitter module in one embodiment;

[0042] Figure 8 This is a schematic diagram of a Hall effect current sensing module in one embodiment;

[0043] Figure 9 This is a schematic diagram of a giant magnetoresistive effect current sensing module in one embodiment;

[0044] Figure 10 This is a schematic diagram of a tunnel magnetoresistance effect measurement module in one embodiment;

[0045] Figure 11 This is a schematic diagram of a fluxgate current sensor module in one embodiment;

[0046] Figure 12 This is a schematic diagram of a fluxgate current sensor module in another embodiment;

[0047] Explanation of reference numerals in the attached figures:

[0048] 01-Current measurement system; 10-Current measurement device; 20-External power supply;

[0049] 100 - Power interface; 101 - Sampling resistor module; 102 - Current transmitter module;

[0050] 103 - Hall effect current sensing module; 104 - Giant magnetoresistive effect current sensing module;

[0051] 105 - Tunnel magnetoresistive effect measurement module; 106 - Fluxgate current sensor module;

[0052] 1010 - First measuring terminal; 1020 - Second test terminal;

[0053] 1030 - Third test terminal; 1040 - Fourth test terminal;

[0054] 1050 - Fifth test terminal; 1060 - Sixth test terminal;

[0055] 1011 - Resistor assembly; 1012 - Receptacle assembly; 1013 - Resistor input terminal;

[0056] 1014 - Resistor output terminal; 1015 - Chip input terminal; 1016 - Chip output terminal;

[0057] 10110 - First resistive element; 10120 - Chip socket assembly;

[0058] 10121 - Resistor pin assembly; 10122 - Chip; 10123 - Second resistor element;

[0059] 1021 - Resistor input terminal; 1022 - First power supply input terminal; 1023 - First grounding terminal;

[0060] 1024 - Current transmitter; 10240 - Input signal isolation circuit; 10241 - Current conversion circuit; 10242 - Output circuit; 1031 - Sensor chip; 1032 - First voltage output terminal;

[0061] 1033 - Second power supply input terminal; 1034 - Second grounding terminal; 1035 - Input interface for the circuit under test;

[0062] 1041 - Giant magnetoresistive chip; 1042 - Third power supply input terminal; 1043 - Third grounding terminal;

[0063] 1044 - Current output terminal; 1045 - Second voltage output terminal; 1046 - Interface for circuit under test;

[0064] 1051 - Fourth power supply input; 1052 - Fourth grounding terminal; 1053 - Third voltage output terminal;

[0065] 1054 - First current sensor; 1061 - Input terminal for measured current; 1062 - Output terminal for measured current;

[0066] 1063 - Fifth power supply input terminal; 1064 - Fifth grounding terminal; 1065 - Fourth voltage output terminal;

[0067] 1066 - Second current sensor. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0069] In today's rapidly evolving technological environment, current detection, as a fundamental component of electronics, plays a crucial role in various engineering applications and scientific research fields. However, traditional current detection experimental devices suffer from a series of limitations, such as their large size, cumbersome operating procedures, and insufficient adaptability. These limitations pose significant challenges for users when training personnel on current detection techniques.

[0070] To avoid the aforementioned limitations, various current measuring devices have been proposed, including portable resistance current meters, high-safety multimeters for current measurement experiments, and multi-functional voltmeters for physics experiments. Portable resistance current meters make resistance current meters portable, while high-safety multimeters for current measurement experiments incorporate safety measures such as waterproofing, protection against electric shock, and high-current protection to address safety issues in laboratory and teaching environments during current measurement. In addition, multi-functional voltmeters for physics experiments can measure the voltage, current, and resistance of various components in a circuit.

[0071] However, the aforementioned current testing devices share a common limitation: they focus only on a single current detection principle and lack integrated development of current detection methods based on different principles. This makes it impossible to meet the requirement for comprehensive comparison of different current detection methods in teaching. This application aims to solve this problem.

[0072] Having described the background technology of the current measuring device provided in the embodiments of this application, the following is a brief description of the implementation environment involved in the current measuring device provided in the embodiments of this application. The current measuring device provided in the embodiments of this application can be applied to, for example... Figure 1 The application environment shown is illustrated. The current measurement system 01 includes a current measuring device 10 and an external power supply 20. The current measuring device 10 is connected to the external power supply 20. The user measures the corresponding current by operating different current measuring components on the current measuring device 10 and using different current measurement principles (e.g., Ohm's law, Hall effect, giant magnetoresistance effect, tunneling magnetoresistance effect, fluxgate effect).

[0073] Those skilled in the art will understand that Figure 1 The structure shown is merely a block diagram of a portion of the structure related to the solution of this application and does not constitute a limitation on the application environment in which the solution of this application is applied. The specific application environment may include more or fewer components than shown in the figure, or a combination of certain components, or different component arrangements.

[0074] Having described the application scenarios of the current measuring device 10 provided in the embodiments of this application above, the current measuring device 10 described in this application will now be described in detail. Figure 2As shown, the current measuring device 10 includes: a power interface 100, a sampling resistor module 101, a current transmitter module 102, a Hall effect current sensing module 103, a giant magnetoresistive effect current sensing module 104, a tunnel magnetoresistive effect measurement module 105, and a fluxgate current sensor module 106; the current measuring device 10 is connected to an external power supply 20 through the power interface 100.

[0075] The sampling resistor module 101 is used to form an ohmic circuit and a first measurement terminal 1010 is provided on the ohmic circuit; the first measurement terminal 1010 is used to provide a test port for the user to test the first current signal of the branch on the ohmic circuit.

[0076] The current transmitter module 102 is used to form a current conversion circuit, and a second test terminal 1020 is provided on the current conversion circuit; the second test terminal 1020 is used to provide a test port for the user to test the second current signal of the branch on the current conversion circuit.

[0077] The Hall effect current sensing module 103 is used to form a Hall circuit and a third test terminal 1030 is provided on the Hall circuit; the third test terminal 1030 is used to provide a signal port for the user to test the third current signal of the branch on the Hall circuit.

[0078] The giant magnetoresistive effect current sensing module 104 is used to form a giant magnetoresistive circuit, and a fourth test terminal 1040 is provided on the giant magnetoresistive circuit; the fourth test terminal 1040 is used to provide the user with a signal port to test the fourth current signal of the branch on the giant magnetoresistive circuit.

[0079] The tunnel magnetoresistive effect measurement module 105 is used to form a tunnel magnetoresistive circuit and a fifth test terminal 1050 is provided on the tunnel magnetoresistive circuit; the fifth test terminal 1050 is used to provide the user with a signal port to test the fifth current signal of the branch on the tunnel magnetoresistive circuit.

[0080] The fluxgate current sensor module 106 is used to form a fluxgate circuit and has a sixth test terminal 1060 on the fluxgate circuit; the sixth test terminal 1060 is used to provide a signal port for the user to test the sixth current signal of the branch on the fluxgate circuit.

[0081] The following sections will provide a detailed description of each of the following modules: sampling resistor module 101, current transmitter module 102, Hall effect current sensing module 103, giant magnetoresistive effect current sensing module 104, tunneling magnetoresistive effect measurement module 105, and fluxgate current sensor module 106.

[0082] First, regarding the sampling resistor module 101, see... Figure 3The sampling resistor module 101 includes a resistor assembly 1011, a socket assembly 1012, a resistor input terminal 1013, a resistor output terminal 1014, a chip input terminal 1015, and a chip output terminal 1016.

[0083] The resistor assembly 1011 is connected to the resistor input terminal 1013 and the resistor output terminal 1014 respectively;

[0084] The socket assembly 1012 is connected to the chip input terminal 1015 and the chip output terminal 1016 respectively;

[0085] The socket assembly 1012 is used to amplify the current signal output by the current measuring device 10.

[0086] The resistor assembly 1011 includes multiple first resistor elements 10110 with different resistance values, see [link to documentation]. Figure 3 The diagram shows four different first resistor elements 10110 with different resistance values: 1W 1Ω, 1W 10Ω, 1 / 4W 1Ω, and 1 / 4W 10Ω, with a precision of one ten-thousandth.

[0087] Among them, see Figure 4 The socket assembly 1012 includes a chip socket assembly 10120 and a resistor pin assembly 10121. The chip socket assembly 10120 is used to connect chips 10122 with different package forms, and the resistor pin assembly 10121 is used to connect second resistor elements 10123 with different resistance values. The second resistor element 10123 is used to cooperate with the chip 10122 to output a current signal that meets the requirements.

[0088] In this embodiment, the first resistive element 10110 in the circuit is a precision resistor with a known resistance value. By measuring the voltage across the first resistive element 10110, the current in the first resistive element 10110 is calculated using Ohm's law. It should be noted that common series connection methods for the first resistive element 10110 include placing it at the low end and placing it at the high end.

[0089] See Figure 5 Low-end placement refers to grounding one end of the first resistor element 10110. Its advantages include facilitating direct measurement of the voltage across the first resistor element 10110 when the measuring instrument (such as the ground terminal of a non-isolated oscilloscope) shares a common ground with the power supply; and reducing the common-mode voltage when using a differential operational amplifier for gain amplification, thus lowering the cost of ordinary operational amplifiers. The disadvantages of low-end placement are that one end must be grounded, limiting its application to any part of the circuit; and the current sensing resistor introduces ground level interference, which may affect the load.

[0090] See Figure 6In this method, the first resistor element, 10110, is not grounded and simply needs to be connected in series in the circuit under test. The advantage of this method is its flexible placement and that it does not affect the grounding of the original circuit. The disadvantages are that it is impossible to directly use a probe with one end grounded to measure the voltage signal across the sampling resistor; and when using a differential op-amp for gain amplification, the common-mode voltage requirement for the op-amp is relatively high, which may increase costs.

[0091] The aforementioned sampling resistor module is equipped with four types of first resistor elements with a precision of 1 / 10,000 (1W 1Ω, 1W 10Ω, 1 / 4W 1Ω, and 1 / 4W 10Ω), applicable to various power / current applications. In addition, the experimental box is equipped with a chip socket assembly 10120 and a resistor pin assembly 10121, which are used to design differential amplifier circuits with different parameters. The chip socket assembly 10120 can accommodate chips in different packages, and the resistor pin assembly 10121 can accommodate second resistor elements 10123 with different resistance values.

[0092] The chip socket assembly 10120 can be a chip socket assembly in DIP14 package or a chip socket assembly in DIP8 package.

[0093] See Figure 3 The chip socket assembly 10120 is connected to the chip input terminal 1015 and the chip output terminal 1016 respectively, and is used to amplify the current signal output by the current measuring device 10.

[0094] It should be noted that the chip input terminal 1015, the chip output terminal 1016, the resistor input terminal 1013, and the resistor output terminal 1014 all support different wiring methods, which can meet a variety of different wiring requirements.

[0095] In this embodiment, the design of the sampling resistor module 101 provides the necessary hardware support for designing a resistance sampling measurement circuit. Users can connect the first resistor element 10110 in series with the circuit using either a "high-end placement" or "low-end placement" method, and then use the chip 10122 and the second resistor element 10123 reserved on the sampling resistor module 101 to achieve circuit design that meets the needs of various scenarios, without the need for additional auxiliary tools such as breadboards.

[0096] In this embodiment, when using the sampling resistor module to measure current, the circuit under test can be connected to any of the first resistor elements 10110 according to actual needs. By measuring the voltage waveform of the first resistor element 10110, and based on the voltage waveform of the first resistor element 10110 and the resistance value corresponding to the first resistor element 10110, the corresponding current waveform can be determined. In addition, if the measured voltage signal of the first resistor element 10110 is too small, a chip 10122 of appropriate size can be placed on the chip socket assembly 10120 to amplify the small voltage signal. In other words, the structure of the sampling resistor module 101 provides great convenience for current measurement using a current sampling scheme.

[0097] Second, regarding the current transmitter module 102, see... Figure 7 The current transmitter module 102 includes a resistor input terminal 1021, a first power input terminal 1022, a first ground terminal 1023, and a current transmitter 1024.

[0098] The current transmitter 1024 includes an input signal isolation circuit 10240, a current conversion circuit 10241, and an output circuit 10242.

[0099] The current transmitter 1024 is model SIN-SDJI-5A. The current measurement range of the current transmitter 1024 is 0-5A, the output current range of the current transmitter 1024 is 4-20mA, and the operating power supply of the current transmitter 1024 is 24VDC.

[0100] In this embodiment, the current transmitter 1024 can convert a large AC current signal into a 4-20mA standard AC current signal and provide the 4-20mA standard AC current signal to a computer, display instrument, or PLC for control. In other words, the current transmitter 1024 is a device for detecting AC current. The function of the current transmitter 1024 is to convert a large AC current into a smaller AC current in a linear proportion for easy detection.

[0101] The current conversion circuit 10241 is the core of the current transmitter. It is a precision full-wave rectifier circuit that can convert the measured current into the corresponding output quantity. The current conversion circuit 10241 is characterized by its simple circuit and good linearity, but its disadvantage is that waveform distortion has a significant impact on it.

[0102] The advantages of the input signal isolation circuit 10240 include: (1) it has driving capability and generally has a large output current; (2) it is low-cost; (3) it does not require an auxiliary power supply during operation and is easy to use; (4) it can measure high-frequency AC signals that Hall sensors cannot measure. The disadvantages of the input signal isolation circuit 10240 include: (1) because the output is large, secondary isolation is required for the acquisition by the microcontroller MCU to protect the device; (2) there is a phase difference between the primary and secondary sides, and phase compensation needs to be performed in the software when the MCU acquires the data, which is quite troublesome; (3) it requires a large size to measure large currents, which affects installation.

[0103] In this embodiment, the current conversion circuit 10241 is model SIN-SDJI-5A, with a current measurement range of 0-5A, an output current range of 4-20mA, and an accuracy of 0.5 class. It operates on 24VDC power and requires a 250Ω resistor to convert the current into a voltage signal.

[0104] It should be noted that when using the current conversion circuit 10241 for current measurement, it can be achieved by connecting the second resistor element 10123 in the sampling resistor module 101, and the current being measured is connected to the wire as per the attached... Figure 7 In the current conversion circuit 10241, the arrow points through the current via, and a 250Ω resistor is connected to the resistor input terminal 1021 to measure the voltage value of the resistor and determine the current value of the circuit under test based on the voltage value of the resistor.

[0105] It should be noted that the resistor input terminal 1021, the first power input terminal 1022, and the first ground terminal 1023 all support different wiring methods, which can meet a variety of different wiring requirements.

[0106] Thirdly, see Figure 8 The Hall effect current sensing module 103 includes a sensor chip 1031, a first voltage output terminal 1032, a second power input terminal 1033, a second ground terminal 1034, and a circuit under test input interface 1035.

[0107] The sensor chip 1031 is model ACS712. The current measurement range of the sensor chip 1031 is ±5A, and the frequency range of the sensor chip 1031 is 0-80kHz.

[0108] It's important to note that the Hall effect refers to the phenomenon where, when a small current passes through a semiconductor wafer placed in a magnetic field, the current is deflected by the magnetic field, creating a voltage difference across the semiconductor in the direction perpendicular to the current. This voltage difference is called the Hall voltage. The magnitude of the Hall voltage is directly proportional to the magnetic field strength and the current flowing through the semiconductor. Based on this direct proportionality between the Hall voltage and the magnetic field strength, a current measuring device can be designed to provide a constant control current. In this case, the magnitude of the Hall current is only affected by the magnetic field strength, and therefore, changes in the Hall voltage can reflect changes in the magnetic field strength. Since the magnetic field is generated by the corresponding current and has a clear linkage with it, this is the basic principle of using a Hall element to measure current intensity.

[0109] The Hall sensor is characterized by its ability to measure AC and DC currents from DC to 200kHz, which is different from the current transmitter module 102, which can only measure AC current and cannot measure DC current.

[0110] In this embodiment, the Hall element chip selected for sensor chip 1031 is model ACS712, which is an integrated linear current sensor chip based on the Hall effect, providing an economical and accurate solution. Sensor chip 1031 is powered by a 5V power supply, with a current measurement range of ±5A, an accuracy of 1.5 class, and a frequency range of 0-80kHz. The output of sensor chip 1031, model ACS712, is superimposed on 0.5Vcc, and the relationship between its output voltage and current is shown in the following formula (1):

[0111]

[0112] In the embodiments of this application, see Figure 8 When using the Hall effect current sensing module 103 to measure current, the first voltage output terminal VCC and the second ground terminal GND are connected to the positive terminal of the 5V power supply and the ground, respectively. The two circuits under test on the right side of the sensor chip 1031 are connected to the interface 1035 and connected in series to the circuit under test. At this time, the relationship between the voltage output of the second power input terminal 1033OUT and the current in the actual circuit under test is given by the above formula (1). That is to say, by measuring the voltage of the second power input terminal OUT, the measured current value can be obtained by conversion using formula (1).

[0113] It should be noted that the first voltage output terminal 1032, the second power input terminal 1033, the second ground terminal 1034, and the circuit under test input interface 1035 all support different wiring methods, which can meet a variety of different wiring requirements.

[0114] Fourth, giant magnetoresistive effect current sensing module 104, see Figure 9It includes a giant magnetoresistive chip 1041, a third power input terminal 1042, a third ground terminal 1043, a current output terminal 1044, a second voltage output terminal 1045, and a circuit under test input interface 1046.

[0115] The giant magnetoresistive chip 1041 is an ACS70331 model chip. The current detection range of the giant magnetoresistive chip 1041 is ±2.5A, the frequency range of the giant magnetoresistive chip 1041 is 0-1MHz, the operating temperature range of the giant magnetoresistive chip 1041 is -20°C to 85°C, and the sensitivity of the giant magnetoresistive chip 1041 is 200mV / A.

[0116] The giant magnetoresistance (GMR) effect refers to the phenomenon where a slight change in the applied magnetic field can cause a drastic change in the resistance of a multilayer film (the resistivity can decrease by more than 10 times compared to that of ordinary magnetic materials and alloys). This phenomenon is particularly pronounced in permalloy and ferromagnetic materials. GMR sensors are widely used in the measurement of current, magnetic field, angular displacement, acceleration, and other parameters.

[0117] The GMR effect exhibits a larger rate of change in magnetoresistance, making GMR elements more sensitive to weak magnetic fields. They can accurately measure both DC and AC currents and offer advantages such as small size, wide response frequency, and no residual magnetic field. However, their manufacturing process is relatively complex and costly, limiting their application primarily to high-precision, low-current measurements. GMR sensors are more sensitive than Hall effect sensors and have a wider range of applications.

[0118] In this embodiment, the giant magnetoresistive chip 1041 is an ACS70331, which is powered by a single 3.3V power supply, has a current detection range of ±2.5A, a frequency range of 0-1MHz, and an operating temperature range of -20°C to 85°C. Its sensitivity is 200mV / A, meaning that when measuring a 1A current, its output voltage is 200mV.

[0119] See Figure 9 When using the Hall effect current sensing module 103 for current measurement, the positive terminal of a 3.3V external power supply is connected to ground between the third power input terminal VCC and the third ground terminal. The second voltage output terminal Dout is not connected, and the current output terminal Aout outputs the current value. The measured current is determined by the attached... Figure 9 The circuit under test on the right is connected to interface 1046. By measuring the voltage at the current output terminal Aout, the voltage is converted into the measured current value according to the 200mV / A sensitivity mentioned above.

[0120] It should be noted that the third power input terminal 1042, the third ground terminal 1043, the current output terminal 1044, the second voltage output terminal 1045, and the circuit under test input interface 1046 all support different wiring methods, which can meet a variety of different wiring requirements.

[0121] Fifth, Tunnel Magnetoresistance Effect Measurement Module 105, see Figure 10 It includes a fourth power input 1051, a fourth grounding terminal 1052, a third voltage output terminal 1053, and multiple first current sensors 1054 with different ranges.

[0122] The first current sensor 1054 includes a current-perforated hole for penetrating the object to be measured.

[0123] The first current sensor 1054 is a TMR7401 current sensor. The first current sensor 1054 is supplied with a power supply voltage of 5V and has a rated output voltage of 3.7V.

[0124] The tunneling magnetoresistive effect (TMR) refers to the effect in a ferromagnetic-insulator thin film (approximately 1 nanometer)-ferromagnetic material where the tunneling resistance varies with the relative orientation of the two ferromagnetic materials. Due to its advantages such as high magnetoresistive capacity and high magnetic field sensitivity, the TMR effect is a fourth-generation magnetic sensor technology. TMR sensors offer advantages such as high accuracy, high sensitivity, low power consumption, small size, good temperature stability, and a wide operating temperature range.

[0125] In this embodiment, a first current sensor 1054 with two measurement ranges is included: a first current sensor 1054 with a 300mA range and a first current sensor 1054 with a 600mA range. For the 300mA range first current sensor 1054, the output voltage... With the measured current Satisfy the following formula (2):

[0126]

[0127] For the first current sensor 1054 with a range of 600mA, the output voltage... With the measured current Satisfy the following formula (3):

[0128]

[0129] In the embodiments of this application, see Figure 10The current to be measured passes through the current through hole in the first current sensor 1054 in the direction of current “I” in the figure. The positive terminal of the +5V power supply and the ground are connected to “+5V” and “GND” respectively. The voltage at “Vout” is measured. The current value can be obtained according to the conversion relationship shown in formula (2) or (3) (this depends on whether the selected first current sensor has a range of 300mA or 600mA).

[0130] It should be noted that the fourth power input 1051, the fourth grounding terminal 1052, and the third voltage output terminal 1053 all support different wiring methods, which can meet a variety of different wiring requirements.

[0131] Sixth, fluxgate current sensor module 106, see Figure 11 It includes a measured current input terminal 1061, a measured current output terminal 1062, a fifth power supply input terminal 1063, a fifth grounding terminal 1064, a fourth voltage output terminal 1065, and multiple second current sensors 1066 with different ranges.

[0132] The current and voltage relationships of the second current sensor 1066 vary depending on its range.

[0133] The fluxgate principle refers to the phenomenon where the inductance of an easily saturated magnetic core changes with the magnitude of the excitation current. This change in inductance leads to a change in magnetic flux, which acts like a door opening or closing, hence the name fluxgate principle. The advantages of the fluxgate principle include a very high upper current limit, minimal temperature influence, low heat generation, and high accuracy—significantly higher than ordinary Hall effect sensors. Furthermore, because fluxgate probes are based on magnetic materials, they possess much more stable temperature characteristics than Hall effect sensors. The disadvantage of the fluxgate principle is that its internal circuitry is relatively susceptible to interference from external magnetic fields.

[0134] See Figure 11 The fluxgate current sensor module 106 is equipped with four types of second current sensors 1066 based on fluxgate technology: CAFR-6A, CAFR-15A, HIT30, and RIT02M. Figure 11 Only two types of second current sensors (CAFR-6A and CAFR-15A 1066) were showcased. They employ excitation closed-loop control technology, eliminating the need for a complex magnetic shielding system compared to traditional solutions. They also utilize self-excitation demagnetization technology, resulting in low zero drift and an expanded measurement range. The CAFR series second current sensor 1066 operates at 5V, with current measurement ranges of ±20A (CAFR-6A) and ±50A (CAFR-15A), an accuracy of 0.8%, and a frequency range of 0-300kHz.

[0135] The relationship between the output voltage Vout and the measured current I of the second current sensor 1066 of CAFR-6A is shown in Equation (4) below. The relationship between the output voltage Vout and the measured current I of the second current sensor 1066 of CAFR-15A is shown in Equation (5) below.

[0136]

[0137]

[0138] The second current sensor 1066 of the HIT30 is powered by ±15V, with a current measurement range of ±30A, an accuracy of 0.5%, and a frequency range of 0-100kHz. The relationship between the measured current I and the voltage Vout across the resistor corresponding to the second current sensor 1066 of the HIT30 is shown in the following equation (6):

[0139]

[0140] The second current sensor 1066 of the RIT02M is powered by ±15V, with a current measurement range of ±0.2A, an accuracy of 0.2%, and a frequency range of 0-100kHz. The relationship between the measured current I and the voltage Vout across the resistor corresponding to the second current sensor 1066 of the RIT02M is shown in the following equation (7):

[0141]

[0142] It should be noted that the measured current input terminal 1061, the measured current output terminal 1062, the fifth power supply input terminal 1063, the fifth grounding terminal 1064, and the fourth voltage output terminal 1065 all support different wiring methods, which can meet a variety of different wiring requirements.

[0143] In the embodiments of this application, see Figure 11 Taking the second current sensor 1066 of CAFR-6A as an example, the three measured current input terminals 1061 on the top of the CAFR-6A chip (these three terminals are internally connected, i.e., at the same potential, and three terminals are set to increase the current carrying capacity), and the three measured current output terminals 1062 on the bottom (these three terminals are internally connected, i.e., at the same potential, and three terminals are set to increase the current carrying capacity). The "+5V" and "0" on the experimental box are connected to the positive terminal and ground of the external 5V power supply. The voltage of "Vout" relative to "Ref" is measured, and the current value can be converted according to the above formula (4) or formula (5).

[0144] It should be noted that enlarged views of the second current sensor 1066 in HIT30 and RIT02M are shown below. Figure 12The direction of “I” is the direction through which the measured current passes. “V+” and “V-” are connected to the positive and negative terminals of the ±15V power supply, respectively. The voltage of “OUT” relative to “GND” is measured. The current value can be obtained by following the conversion formula of the above formula (6) or formula (7).

[0145] 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 application.

[0146] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A current measuring device, characterized by, The current measurement device comprises: a power supply interface, a sampling resistance module, a current transmission module, a Hall effect current sensing module, a giant magnetoresistance effect current sensing module, a tunnel magnetoresistance effect measurement module and a magnetic flux gate current sensor module; the current measurement device is connected with an external power supply through the power supply interface; the sampling resistance module comprises a resistance component; the resistance component comprises a plurality of first resistance elements with different resistance values; the series connection mode of the first resistance elements comprises low-end placement and high-end placement; the low-end placement means that one end of the first resistance element is grounded; the high-end placement means that the first resistance element is not grounded; The first resistance elements are connected in series into a circuit in the high-end placement or the low-end placement, and a reserved chip and a second resistance element on the sampling resistance module are used to realize circuit design meeting various scene requirements; The sampling resistance module is used to form an ohmic circuit, and a first measurement terminal is arranged on the ohmic circuit; the first measurement terminal is used to provide a test port for a user to test a first current signal of a branch on the ohmic circuit; The current transmission module is used to form a current conversion circuit, and a second test terminal is arranged on the current conversion circuit; the second test terminal is used to provide a test port for the user to test a second current signal of a branch on the current conversion circuit; The Hall effect current sensing module is used to form a Hall circuit, and a third test terminal is arranged on the Hall circuit; the third test terminal is used to provide a signal port for the user to test a third current signal of a branch on the Hall circuit; The giant magnetoresistance effect current sensing module is used to form a giant magnetoresistance circuit, and a fourth test terminal is arranged on the giant magnetoresistance circuit; the fourth test terminal is used to provide a signal port for the user to test a fourth current signal of a branch on the giant magnetoresistance circuit; The tunnel magnetoresistance effect measurement module is used to form a tunnel magnetoresistance circuit, and a fifth test terminal is arranged on the tunnel magnetoresistance circuit; the fifth test terminal is used to provide a signal port for the user to test a fifth current signal of a branch on the tunnel magnetoresistance circuit; The magnetic flux gate current sensor module is used to form a magnetic flux gate circuit, and a sixth test terminal is arranged on the magnetic flux gate circuit; the sixth test terminal is used to provide a signal port for the user to test a sixth current signal of a branch on the magnetic flux gate circuit.

2. The current measuring device of claim 1, wherein, The sampling resistance module further comprises a socket component, a resistance access terminal, a resistance exit terminal, a chip access terminal and a chip exit terminal; The resistance component is connected with the resistance access terminal and the resistance exit terminal respectively; The socket component is connected with the chip access terminal and the chip exit terminal respectively; The socket component is used to amplify a current signal output by the current measurement device.

3. The current measuring device of claim 2, wherein, The socket assembly comprises a chip socket assembly for connecting chips in different package forms and a resistance pin assembly for connecting second resistance elements with different resistance values; the second resistance elements are used to cooperate with the chips to output required current signals.

4. The current measuring device of claim 1, wherein, The current sending module comprises a resistance access end, a first power supply access end, a first ground end and a current sender. The current sender comprises an input signal isolation circuit, a current conversion circuit and an output circuit.

5. The current measuring device of claim 4, wherein, The model of the current sender is SIN-SDJI-5A, the current measurement range of the current sender is 0-5A, the output current range of the current sender is 4-20mA, and the working power supply of the current sender is 24VDC.

6. The current measuring device of claim 1, wherein, The Hall effect current sensing module comprises a sensor chip, a first voltage output end, a second power supply access end, a second ground end and a measured circuit access interface. The model of the sensor chip is ACS712, the current measurement range of the sensor chip is ±5A, and the frequency range of the sensor chip is 0-80kHz.

7. The current measuring device of claim 1, wherein, The giant magnetoresistance effect current sensing module comprises a giant magnetoresistance chip, a third power supply access end, a third ground end, a current output end, a second voltage output end and a measured circuit access interface. The giant magnetoresistance chip is a chip with a model of ACS70331, the current detection range of the giant magnetoresistance chip is ±2.5A, the frequency range of the giant magnetoresistance chip is 0-1MHz, the working temperature range of the giant magnetoresistance chip is -20°C-85°C, and the sensitivity of the giant magnetoresistance chip is 200mV / A.

8. The current measuring device of claim 1, wherein, The tunnel magnetoresistance effect measurement module comprises a fourth power supply access end, a fourth ground end, a third voltage output end and a plurality of first current sensors with different ranges. The first current sensor comprises a current through hole for penetrating a to-be-measured object. The model of the first current sensor is a TMR7401 current sensor, the power supply voltage of the first current sensor is 5V, and the rated output voltage of the first current sensor is 3.7V.

9. The current measuring device of claim 1, wherein, The magnetic flux gate current sensor module comprises a measured current input end, a measured current output end, a fifth power supply access end, a fifth ground end, a fourth voltage output end and a plurality of second current sensors with different ranges. The second current sensors with different ranges have different current-voltage relationships.

10. The current measuring device according to any one of claims 1 to 9, characterized in that The power supply interface, the sampling resistance module, the current sending module, the Hall effect current sensing module, the giant magnetoresistance effect current sensing module, the tunnel magnetoresistance effect measurement module and the magnetic flux gate current sensor module all support a plurality of different connection modes.

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