A demonstration device for investigating the Hall effect

Abstract

A demonstration device for exploring the Hall effect includes a measurement system, an electromagnetic system, and a magnetoelectric conversion system. The electromagnetic system generates a magnetic field signal under the action of the measured current. The magnetoelectric conversion system receives the magnetic field signal, converts it into a corresponding voltage signal, and outputs it to the measurement system for processing. The measurement system includes a lithium iron phosphate battery, a toggle switch, an ESP32 microcontroller, an ADS1115 chip, a voltage measurement port, and a current measurement port, used to measure the Hall voltage and its operating current output by the magnetoelectric conversion system. The VDD pin of the ADS1115 chip and the 3V3 pin of the ESP32 microcontroller are connected to the positive terminal of the lithium iron phosphate battery via wires and the toggle switch. The ESP32 microcontroller has at least three GND pins. The GND pins of the ADS1115 chip and the first GND pin of the ESP32 microcontroller are connected to the negative terminal of the lithium iron phosphate battery. The SCL, SDA, and ADDR pins of the ADS1115 chip are connected to pins 22, 21, and the second GND pin of the ESP32 microcontroller via wires, respectively.

Description

Technical Field

[0001] This utility model relates to the field of magnetic field measurement demonstration technology, specifically to a demonstration device for exploring the Hall effect. Background Technology

[0002] With the increasing demand for basic physics teaching and popular science on sensor principles, the Hall effect, as an important phenomenon in the field of electromagnetic induction, is widely used in teaching experiments, scientific research verification, and engineering training. The Hall effect refers to the generation of an electromotive force (EMF) perpendicular to both the current and magnetic field directions when a current-carrying conductor or semiconductor is placed in a magnetic field perpendicular to the current direction. This EMF is called the Hall voltage, which is expressed as U = (1 / ne)·(BI / d), where U is the Hall voltage, I is the current through the Hall sensor, B is the magnetic field strength perpendicular to the plane of the Hall sensor, n is the carrier concentration, and e is the carrier charge. This phenomenon not only provides a theoretical basis for technologies such as magnetic field measurement, current detection, and displacement sensing, but has also become an indispensable demonstration content in physics teaching.

[0003] Currently, common Hall effect demonstration devices typically include a magnetic field generating structure, a Hall sensor, a signal acquisition circuit, and a display module. Their principle is to generate a voltage output from the Hall element under the influence of a controllable magnetic field, and then use a processing system to read and display the data. However, existing devices still have significant limitations in terms of structural design and functional performance: on the one hand, most devices use movable permanent magnets or simple electromagnets, resulting in a limited range of magnetic field strength adjustment and a lack of good controllability and repeatability; on the other hand, the Hall voltage signal itself is relatively weak, and traditional circuit designs often lack effective filtering, isolation, and anti-interference mechanisms, leading to large fluctuations and poor stability in the measured data during experiments. Some demonstration devices fail to effectively integrate modern microcontrollers and high-precision analog-to-digital converter chips, resulting in limited data processing capabilities and a lack of multi-channel expansion, dynamic display, and data recording capabilities, making it difficult to meet the current digital needs of teaching and experiments.

[0004] In view of the above, this application proposes a demonstration device for exploring the Hall effect, so as to realize the complete conversion link of magnetic field to electrical signal, improve the demonstration accuracy and teaching interactivity, and provide a more valuable experimental platform for related applications. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a demonstration device for exploring the Hall effect, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A demonstration device for exploring the Hall effect includes a measurement system, an electromagnetic system, and a magnetoelectric conversion system. The electromagnetic system generates a magnetic field signal at the Hall sensor of the magnetoelectric conversion system under the action of the measured current. The magnetoelectric conversion system receives the magnetic field signal, converts it into a corresponding Hall voltage signal, and outputs it to the measurement system for processing. The measurement system simultaneously measures the operating current signal of the magnetoelectric conversion system.

[0008] The measurement system includes a lithium iron phosphate battery, an A toggle switch, an ESP32 microcontroller, an ADS1115 chip, a voltage measurement port, and a current measurement port.

[0009] The VDD pin of the ADS1115 chip and the 3V3 pin of the ESP32 microcontroller are connected to the positive terminal of the lithium iron phosphate battery via wires and the A toggle switch. The ESP32 microcontroller has at least three GND pins. The GND pin of the ADS1115 chip and the first GND pin of the ESP32 microcontroller are connected to the negative terminal of the lithium iron phosphate battery. The SCL, SDA, and ADDR pins of the ADS1115 chip are connected to pins 22, 21, and the second GND pin of the ESP32 microcontroller via wires, respectively.

[0010] The current signal provided by the current measurement port flows through a first resistor set in series, and the two ends of the first resistor are respectively connected to the A0 and A1 pins of the ADS1115 chip through wires;

[0011] The voltage measurement port is connected to a voltage divider circuit via a wire. The voltage divider circuit consists of a second resistor and a third resistor connected in series. The A2 and A3 pins of the ADS1115 chip are respectively connected to the two ends of the third resistor in the voltage divider circuit via wires to collect the voltage divider signal.

[0012] The magnetoelectric conversion system includes a power supply, a B toggle switch, a potentiometer, and a Hall sensor. The positive terminal of the power supply is connected to the input terminal of the potentiometer via a wire and the toggle switch. The output terminal of the potentiometer is connected to one end of a first resistor via a wire. The other end of the first resistor is connected to the VCC pin of the Hall sensor. The OUT pin of the Hall sensor is connected to the positive terminal of the voltage measurement port, and the GND pin is connected to the negative terminal of the voltage measurement port and the negative terminal of the power supply, respectively.

[0013] The electromagnetic system includes a first electromagnet, a second electromagnet, a C-type toggle switch, and a pointer-type ammeter. The pointer-type ammeter is connected in series in the branch of the first electromagnet. The first and second electromagnets are connected in parallel via wires and the C-type toggle switch to a DC power supply with an output range of 3-12V. The first and second electromagnets connected in parallel generate an adjustable magnetic field. The Hall sensor is located within the magnetic field's area of ​​action, and its sensing end receives the magnetic field and outputs a corresponding voltage signal to the voltage measurement port.

[0014] Optionally, the 3V3 pin of the ESP32 microcontroller is connected to the positive terminal of the lithium iron phosphate battery via a toggle switch, the GND pin of the ESP32 microcontroller is connected to the negative terminal of the lithium iron phosphate battery, and the positive and negative terminals of the lithium iron phosphate battery are respectively connected to the positive and negative terminals of the charging module.

[0015] Optionally, the first resistor is a 1Ω sampling resistor.

[0016] Optionally, the second resistor is a 510Ω resistor, and the third resistor is a 100Ω resistor.

[0017] Optionally, the power supply consists of three 1.5V dry cell batteries connected in series.

[0018] Optionally, the Hall sensor is a 95A linear Hall sensor.

[0019] Optionally, the positive terminal of the DC power supply is connected to parallel node N1 via a wire and the C-toggle switch. Parallel node N1 branches into two parallel branches. One branch connects the pointer ammeter and the input terminal of the first electromagnet sequentially via a wire, and the output terminal of the first electromagnet is connected to parallel node N2 via a wire. The other branch connects the input terminal of the second electromagnet via a wire, and the output terminal of the second electromagnet is connected to parallel node N2 via a wire. Parallel node N2 is connected to the negative terminal of the DC power supply via a wire.

[0020] This invention provides a demonstration device for exploring the Hall effect, which has the following beneficial effects:

[0021] 1. This utility model provides a demonstration device for exploring the Hall effect. By utilizing the ADS1115 high-precision analog-to-digital converter chip and combining it with differential sampling circuit design, common-mode interference and noise are effectively reduced, the measurement accuracy of voltage and current signals is improved, and the accurate acquisition of the Hall sensor output signal is achieved.

[0022] 2. This utility model provides a demonstration device for exploring the Hall effect. By combining the ESP32 microcontroller and the ADS1115 chip, it realizes the synchronous acquisition and digital processing of Hall voltage and operating current, providing a solid foundation for subsequent data analysis and visualization.

[0023] 3. This utility model provides a demonstration device for exploring the Hall effect. It generates an adjustable magnetic field by using two DC electromagnets connected in parallel. Combined with a Hall sensor, it realizes the conversion of magnetic field strength into voltage signal, enhances the demonstration effect of the device, and facilitates teaching and experimental observation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the measurement system circuit of this utility model;

[0025] Figure 2 This is a schematic diagram of the measurement system structure of this utility model;

[0026] Figure 3 This is a schematic diagram of the structure of this utility model.

[0027] In the diagram: 1. Measurement system; 2. Electromagnetic system; 21. C toggle switch; 3. Magnetoelectric conversion system; 31. Power supply; 32. Potentiometer; 33. Hall sensor; 34. B toggle switch; 4. Lithium iron phosphate battery; 5. ESP32 microcontroller; 51. A toggle switch; 6. ADS1115 chip; 7. Voltage measurement port; 8. Current measurement port; 9. First resistor; 10. Second resistor; 11. Third resistor; 12. Charging module; 13. Pointer ammeter; 14. First electromagnet; 15. Second electromagnet. Detailed Implementation

[0028] In order to make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0029] In the description of this utility model, it should be understood that the terms "lateral", "longitudinal", "end", "edge", "sidewall", "upper", "lower", "upper part", "lower part", "directly above", "surface", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", "end", "head", "tail", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] This application proposes a demonstration device for exploring the Hall effect, as detailed below:

[0031] For reference Figure 1-2 This application mainly consists of three parts: a measurement system 1, an electromagnetic system 2, and a magnetoelectric conversion system 3. It is a complete link that converts current into magnetic field and then into electrical signal and processes it into readable value, thereby ensuring measurement accuracy, anti-interference and stability.

[0032] For reference Figure 1-2 The measurement system 1 includes a lithium iron phosphate battery 4, an A toggle switch 51, an ESP32 microcontroller 5, an ADS1115 chip 6, a voltage measurement port 7, and a current measurement port 8. It should be noted that the above structures are all mature existing technologies, and this application will not elaborate on this part.

[0033] For reference Figure 1 The 3V3 pin of the ESP32 microcontroller 5 is connected to the positive terminal of the lithium iron phosphate battery 4 via a toggle switch A 51, and the GND pin of the ESP32 microcontroller 5 is connected to the negative terminal of the lithium iron phosphate battery 5. The positive and negative terminals of the lithium iron phosphate battery 4 are connected to the positive and negative terminals of the charging module 12, respectively. By setting a switch between the positive terminal of the lithium iron phosphate battery 4 and the 3V3 pin of the ESP32, the power supply to the ESP32 microcontroller 5 can be cut off or connected as needed, reducing the system's standby power consumption. Furthermore, the lithium iron phosphate battery 4 directly provides a stable operating voltage to the ESP32 microcontroller 5, reducing voltage regulation losses. Simultaneously, the lithium iron phosphate battery 4 is connected in parallel with the charging module 12, allowing the lithium iron phosphate battery 4 to charge when the system is running or stopped, improving the system's battery life and operational flexibility.

[0034] It should be noted that the ESP32 microcontroller has at least three GND pins (see reference). Figure 2 The following GND pins for ESP32 microcontroller 5 (first, second, and third) refer to one of the GND pins on the ESP32 microcontroller 5. The use of "first" and "second" does not imply any specific order. For details, please refer to [reference needed]. Figure 2 The representation in the text.

[0035] For reference Figure 1-2The SCL, SDA, and ADDR pins of the ADS1115 chip 6 are connected to pins 22, 21, and the second GND pin of the ESP32 microcontroller 5 via wires, respectively. The GND pin of the ADS1115 chip 6 is connected to the first GND pin of the ESP32 microcontroller 5 to establish a common ground reference, ensuring a unified reference potential during I²C bus and analog signal transmission, reducing signal drift caused by ground potential differences, and improving communication stability and anti-interference capability. The SCL pin of the ADS1115 chip 6 is connected to pin 22 of the ESP32 microcontroller 5 as the clock signal line for I²C communication; the SDA pin of the ADS1115 chip 6 is connected to pin 21 of the ESP32 microcontroller 5 as the data transmission line for I²C communication. Through this connection method, the ESP32 microcontroller 5 can perform high-speed, bidirectional, digital data transmission with the ADS1115 chip 6 based on the standard I²C protocol. Connect the ADDR pin of the ADS1115 chip 6 to the second GND pin of the ESP32 microcontroller 5, and fix the logic level of this pin to low.

[0036] For reference Figure 1-2 The current signal provided by the current measurement port 8 flows through the first resistor 9 set in series. The output of the current measurement port 8 is a current signal. When the current passes through the first resistor 9 in series, a voltage difference will be generated across the resistor according to Ohm's law (I=U / R). This voltage difference is the signal to be acquired later. The two ends of the first resistor 9 are connected to the A0 and A1 pins of the ADS1115 chip 6 respectively through wires. It is a differential input mode. Its differential acquisition can directly measure the voltage difference across the resistor and can cancel some common-mode noise. By selecting an appropriate resistor value, the current signal can be converted into a safe voltage range that the ADS1115 chip 6 can measure. This avoids damage to the ADS1115 chip due to excessive input voltage and ensures the highest possible resolution.

[0037] Furthermore, the first resistor 9 is a 1Ω sampling resistor.

[0038] For reference Figure 1-2The output signal of voltage measurement port 7 may exceed the input allowable range of ADS1115 chip 6. Therefore, a voltage divider circuit is connected to the output of voltage measurement port 7 via a wire. The voltage divider circuit consists of a second resistor 10 and a third resistor 11 connected in series, which reduces the voltage proportionally. The A2 and A3 pins of ADS1115 chip 6 are connected to the two ends of the third resistor 11 in the voltage divider circuit via wires, which is equivalent to measuring the voltage drop across the third resistor 11 in a differential input mode. Thus, the voltage acquired by ADS1115 chip 6 is the voltage divided value. This connection method uses a voltage divider circuit to proportionally reduce the output of voltage measurement port 7 and acquires the divided voltage signal through the A2 / A3 differential channels of ADS1115 chip 6, which protects the ADC chip and ensures high-precision measurement of the original voltage within a safe range.

[0039] Furthermore, the second resistor 10 is a 510Ω resistor, and the third resistor 11 is a 100Ω resistor; the combination of the 510Ω and 100Ω resistors forms a voltage divider ratio of approximately 1:6.1, reducing the input voltage to approximately 16.4% of the original. This ensures that the ADS1115 chip 6 can accurately sample within a safe range under high voltage input conditions, while also reducing power consumption and noise interference.

[0040] For reference Figure 3 The magnetoelectric conversion system 3 includes a power supply 31, a B-toggle switch 34, a potentiometer 32, and a Hall sensor 33. The positive terminal of the power supply 31 is connected to the input terminal of the potentiometer 32 via the B-toggle switch 34. The B-toggle switch 34 controls the on / off state of the power supply circuit from the power supply 31 to the Hall sensor 33, thereby realizing the power switch control of the Hall sensor 33. The output terminal of the potentiometer 32 is connected to one end of a first resistor 9 via a wire. The other end of the first resistor 9 is connected to the VCC pin of the Hall sensor 33. Its power supply 31 consists of three 1.5V dry batteries connected in series, outputting 4.5V to provide a stable DC power supply for the Hall sensor 33. The potentiometer 32 is used to adjust the magnitude of the supply voltage, realizing fine adjustment of the supply voltage of the Hall sensor 33. In this structure, the first resistor 9 not only serves as part of the power supply path but also plays a key role in current-to-voltage conversion. Since the subsequent ADS1115 chip 6 cannot directly measure current, but can only read voltage signals, a voltage proportional to the operating current of the Hall sensor 33 can be formed across its terminals by connecting the first resistor 9 in series in the power supply circuit, thus indirectly reflecting the sensor's operating current. Considering that the operating current of the Hall sensor 33 in this system is relatively small, the generated voltage will not cause power supply problems, nor will it affect the stability of the sensor.

[0041] The OUT pin of Hall sensor 33 is connected to the positive terminal of voltage measurement port 7. The voltage signal output by Hall sensor 33 is sent to voltage measurement port 7, allowing the detection result of Hall sensor 33 to be accurately read and processed by the subsequent ESP32 microcontroller 5. The third GND pin of Hall sensor 33 is connected to the negative terminal of voltage measurement port 7, ensuring that the Hall sensor and voltage measurement port 7 share a common ground, ensuring consistent signal potential, and avoiding measurement errors or signal interference. A 95A linear Hall sensor is selected for Hall sensor 33.

[0042] Therefore, the power supply voltage of Hall sensor 33 can be adjusted by potentiometer 32 to flexibly control the sensitivity of Hall sensor 33; the magnetic field signal output by Hall sensor 33 is converted into a voltage signal and acquired through voltage measurement port 7 to achieve accurate detection of magnetic field changes; the common ground design ensures signal stability and avoids errors caused by potential drift.

[0043] For reference Figure 3 The magnetic field signal output by Hall sensor 33 is converted into a voltage signal. This process is completed by the electromagnetic system 2. The electromagnetic system 2 generates a magnetic field and "transmits" the measured magnetic field signal to the vicinity of Hall sensor 33 in a form suitable for Hall sensor 33 to sense. Then, Hall sensor 33 senses this magnetic field and converts the magnetic field strength into a corresponding voltage signal output.

[0044] Furthermore, the electromagnetic system 2 includes a first electromagnet 14, a second electromagnet 15, a C-type toggle switch 21, and a pointer-type ammeter 13. The pointer-type ammeter 13 is connected in series in the branch of the first electromagnet 14, and the current through the first electromagnet 14 can be read by the pointer-type ammeter 13. The rated voltage of the first electromagnet 14 and the second electromagnet 15 is 12V. The DC electromagnets (the first electromagnet 14 and the second electromagnet 15) are connected in parallel to a DC power supply with an output range of 3-12V. The positive terminal of the DC power supply is first controlled by the C-type toggle switch 21 to control its on / off state, and then connected to the parallel node N1 through a wire. The C-type toggle switch 21 is set between the positive terminal of the DC power supply and the parallel node N1 to uniformly control the power supply circuits of the two DC electromagnets, thereby realizing the overall start and stop of the electromagnetic system. The parallel node N1 branches into two parallel branches.

[0045] One of them consists of parallel node N1 connected in sequence to the input terminal of pointer ammeter 13 and first electromagnet 14 via wires, and the output terminal of first electromagnet 14 is connected to parallel node N2 via wires.

[0046] Another connection is made by connecting the input terminal of the second electromagnet 15 to the parallel node N1 via a wire, and connecting the output terminal of the second electromagnet 15 to the parallel node N2 via a wire; the parallel node N2 is connected to the negative terminal of the DC power supply via a wire.

[0047] Through the above connection structure, two DC electromagnets (first electromagnet 14 and second electromagnet 15) are simultaneously powered and generate magnetic fields. The magnetic induction intensity can be adjusted by adjusting the power supply current, thereby forming a controllable magnetic field in the target area.

[0048] Furthermore, the current directions of the two DC electromagnets (first electromagnet 14 and second electromagnet 15) are designed to be consistent, so that the magnetic field directions they generate are the same, thereby forming a magnetic field superposition enhancement effect in the space between them, improving the magnetic induction intensity and spatial uniformity; where the current direction refers to the direction of the current in the electromagnet coil, the two electromagnets are arranged with current in the same direction, thereby ensuring that the magnetic field direction is consistent; the Hall sensor 33 (such as the 95A model) is set in the area where the magnetic fields of the two electromagnets are superimposed, and its sensitive axis is consistent with the direction of magnetic field synthesis, so as to achieve accurate acquisition of the superimposed magnetic field intensity.

[0049] Furthermore, by adjusting the output voltage U of the DC power supply, the current I in the parallel branch can be changed, thereby adjusting the magnetic field strength generated by the electromagnet. According to Ohm's law, the magnitude of the current I can be expressed as: I = U / R1, where R1 is the internal resistance of the electromagnet EM1. Through this adjustment mechanism, the magnetic field strength can be continuously adjusted to meet the needs of different Hall effect demonstration scenarios.

[0050] Based on this, in order to achieve real-time measurement of variable I in the formula U=(1 / ne)·(BI / d), this application connects a 1Ω sampling resistor (i.e., the first resistor 9) in series in the power supply circuit of the Hall sensor 33. Since the power supply current of the Hall sensor 33 is small, the operating current I=ΔU / 1Ω can be accurately calculated by detecting the voltage difference ΔU across the resistor; this voltage difference signal is input to the A0 / A1 channel of the ADS1115 chip 6 in a differential manner, and is acquired and processed by the ESP32 microcontroller 5 to obtain the real-time value of the Hall element operating current I.

[0051] Therefore, this application achieves real-time and accurate measurement of the current term I in the Hall effect formula by connecting a sampling resistor in series in the power supply circuit of the Hall sensor 33 and using differential acquisition.

[0052] In this invention, the working steps of the device are as follows:

[0053] 1. First, ensure that the lithium iron phosphate battery 4 is charged and correctly connected to the ESP32 microcontroller 5 and the ADS1115 chip 6; check the parallel connection status of the charging module 12 and the lithium iron phosphate battery 4 to ensure that it can be charged during operation or shutdown; turn on the switch located between the positive terminal of the lithium iron phosphate battery 4 and the 3V3 pin of the ESP32 microcontroller 5 to power the measurement system.

[0054] 2. Next, the positive terminal of the DC power supply is first controlled by the C toggle switch 21 to switch its on / off state, and then connected to the parallel node N1 through a wire. N1 branches into two parallel branches:

[0055] ① Branch 1: Passes sequentially through pointer ammeter 13 → electromagnet EM1 → parallel node N2;

[0056] ② Branch 2: Directly passes through electromagnet EM2 → parallel node N2;

[0057] N2 is then connected to the negative terminal of the DC power supply through a wire, forming a parallel power supply circuit for the two electromagnets.

[0058] The current directions of the two electromagnet coils are kept in the same direction to ensure that magnetic fields are generated in the same direction. The magnetic fields are superimposed in the middle region, which improves the magnetic field strength and uniformity. By adjusting the DC power supply output voltage (3~12V), the current magnitude I = U / R1 in the parallel branch is changed, and the magnetic field strength can be dynamically controlled.

[0059] 3. Then, in the magnetoelectric conversion system 3, the positive terminal of the power supply 31 is connected to the input terminal of the potentiometer 32 through the B toggle switch. Adjusting the potentiometer knob changes the magnitude of the working current. This current is connected to the VCC pin of the Hall sensor 33 through a 1Ω sampling resistor. By adjusting the potentiometer, the working current of the Hall sensor is changed, and its sensitivity is indirectly controlled. The magnetic field generated by the electromagnet acts on the Hall sensor 33. The Hall sensor 33 converts the magnetic field strength into a voltage signal and outputs it from the OUT pin. This voltage signal enters the voltage measurement port 7, is reduced to a safe range by the voltage divider circuit, and the divided signal enters the A2 / A3 differential input channel of the ADS1115 chip 6.

[0060] 4. Finally, the operating current of Hall sensor 33 generates a voltage difference through a 1Ω sampling resistor. This voltage difference is directly input to the A0 / A1 differential channels of ADS1115 chip 6 to achieve real-time measurement of the operating current of Hall sensor. ADS1115 chip 6 transmits the collected voltage and current data to ESP32 microcontroller 5 through I²C interfaces (SCL-2, SDA-21). ESP32 microcontroller 5 processes the collected data and, combined with the electromagnet current value, calculates the relevant parameters of Hall effect. The processed data can be viewed and analyzed in real time via serial port, Bluetooth, display screen, or host computer.

[0061] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of this utility model. All such changes and modifications fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A demonstration apparatus for investigating the Hall effect, characterised in that: The system includes a measurement system (1), an electromagnetic system (2), and a magnetoelectric conversion system (3). The electromagnetic system (2) generates a magnetic field signal at the Hall sensor (33) of the magnetoelectric conversion system (3) under the action of the measured current. The magnetoelectric conversion system (3) receives the magnetic field signal, converts it into a corresponding Hall voltage signal, and outputs it to the measurement system (1) for processing. The measurement system (1) simultaneously measures the working current signal of the magnetoelectric conversion system (3). The measurement system (1) includes a lithium iron phosphate battery (4), an A toggle switch (51), an ESP32 microcontroller (5), an ADS1115 chip (6), a voltage measurement port (7), and a current measurement port (8). The VDD pin of the ADS1115 chip (6) and the 3V3 pin of the ESP32 microcontroller (5) are connected to the positive terminal of the lithium iron phosphate battery (4) via wires and the A toggle switch (51). The ESP32 microcontroller (5) has at least three GND pins. The GND pin of the ADS1115 chip (6) and the first GND pin of the ESP32 microcontroller (5) are connected to the negative terminal of the lithium iron phosphate battery (4). The SCL, SDA, and ADDR pins of the ADS1115 chip (6) are connected to pins 22, 21, and the second GND pin of the ESP32 microcontroller (5) via wires, respectively. The current signal provided by the current measurement port (8) flows through the first resistor (9) set in series. The two ends of the first resistor (9) are respectively connected to the A0 and A1 pins of the ADS1115 chip (6) through wires. The voltage measurement port (7) is connected to a voltage divider circuit via a wire. The voltage divider circuit is composed of a second resistor (10) and a third resistor (11) connected in series. The A2 and A3 pins of the ADS1115 chip (6) are connected to the two ends of the third resistor (11) in the voltage divider circuit via wires to collect the voltage divider signal. The magnetoelectric conversion system (3) includes a power supply (31), a B toggle switch (34), a potentiometer (32), and a Hall sensor (33). The positive terminal of the power supply (31) is connected to the input terminal of the potentiometer (32) via a wire and the B toggle switch (34). The output terminal of the potentiometer is connected to one end of a first resistor (9) via a wire. The other end of the first resistor (9) is connected to the VCC pin of the Hall sensor (33). The OUT pin of the Hall sensor (33) is connected to the positive terminal of the voltage measurement port (7), and the GND pin is connected to the negative terminal of the voltage measurement port (7) and the negative terminal of the power supply (31), respectively. The electromagnetic system (2) includes a first electromagnet (14), a second electromagnet (15), a C-type toggle switch (21), and a pointer ammeter (13). The pointer ammeter (13) is connected in series in the branch of the first electromagnet (14). The first electromagnet (14) and the second electromagnet (15) are connected in parallel through wires and the C-type toggle switch (21) to a DC power supply with an output range of 3 to 12V. The first electromagnet (14) and the second electromagnet (15) connected in parallel generate an adjustable magnetic field. The Hall sensor (33) is set in the magnetic field area. Its sensing end receives the magnetic field and outputs the corresponding voltage signal to the voltage measurement port (7).

2. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The 3V3 pin of the ESP32 microcontroller (5) is connected to the positive terminal of the lithium iron phosphate battery (4) through the A toggle switch (51). The GND pin of the ESP32 microcontroller (5) is connected to the negative terminal of the lithium iron phosphate battery (4). The positive and negative terminals of the lithium iron phosphate battery (4) are respectively connected to the positive and negative terminals of the charging module (12).

3. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The first resistor (9) is a 1Ω sampling resistor.

4. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The second resistor (10) is a 510Ω resistor, and the third resistor (11) is a 100Ω resistor.

5. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The power supply (31) consists of three 1.5V dry batteries connected in series.

6. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The Hall sensor (33) is a 95A linear Hall sensor.

7. The demonstration device for exploring the Hall effect according to claim 1, characterized in that: The positive terminal of the DC power supply is connected to parallel node N1 via a wire and the C toggle switch (21). Parallel node N1 branches into two parallel branches. One branch connects the input terminals of the pointer ammeter (13) and the first electromagnet (14) via a wire, and the output terminal of the first electromagnet (14) is connected to parallel node N2 via a wire. The other branch connects the input terminal of the second electromagnet (15) via a wire, and the output terminal of the second electromagnet (15) is connected to parallel node N2 via a wire. Parallel node N2 is connected to the negative terminal of the DC power supply via a wire.

Images