Test pencil based on Hall effect

Abstract

The utility model relates to the field of electrician tools, in particular to a Hall effect-based test pencil, which comprises a test electrode, a current-limiting resistor, a step-down transformer, a hand touch electrode, an electromagnetic coil, a linear Hall element, a power supply unit and a voltage display unit, and is characterized in that the test electrode, the current-limiting resistor and a primary coil of the step-down transformer are connected in series with the hand touch electrode; a secondary coil of the step-down transformer is connected with the electromagnetic coil and the power supply unit, the linear Hall element is arranged opposite to the electromagnetic coil, the power supply unit is electrically connected with the linear Hall element and the voltage display unit, and the voltage display unit is electrically connected with the linear Hall element. Convenience in use and voltage reading of the test pencil can be improved.

Description

Technical Field

[0001] The present application relates to the field of electrical tools, and in particular to an electrical tester based on the Hall effect. Background Art

[0002] An electrician's tester is a common electrical tool used to test whether wires are live. It is often used to detect whether the phase line connection in an AC circuit is correct, or to determine whether the wires carry voltage that is dangerous to human safety, providing great convenience for electricians' work.

[0003] The tester has a neon bulb in the body, a test electrode at the tip, and a finger electrode at the end. The neon bulb is connected between the test electrode and the finger electrode via a resistor. To test whether a wire is live, the tester's hand touches the finger electrode, which in turn brings the test electrode into contact with the wire. If the wire is live, current flows through the test electrode, resistor, neon bulb, finger electrode, and the body to the ground, causing the neon bulb to glow. By observing whether the neon bulb glows, you can determine whether the wire is live.

[0004] When using a traditional voltage tester to check if a wire is live, the low brightness of the neon bulb makes it difficult to see clearly during the day or under strong sunlight, potentially leading to misjudgment. Furthermore, traditional voltage testers cannot determine the voltage level, limiting their use cases. Recently, newer voltage testers have emerged that divide the voltage applied by the test electrodes using resistors, processing it, and displaying the voltage value on a display screen. However, these new testers rely on batteries for power, making them bulky and difficult to carry and use. Furthermore, unstable voltage in the wire under test can easily cause the voltage display on the tester to fluctuate rapidly, affecting accurate voltage readings. Utility Model Content

[0005] In order to improve the convenience of using an electric tester and reading voltage, the present application provides an electric tester based on the Hall effect.

[0006] The Hall effect-based tester provided in this application adopts the following technical solutions:

[0007] A Hall effect-based electrician's pen includes a test electrode, a current-limiting resistor, a step-down transformer, a touch electrode, an electromagnetic coil, a linear Hall, a power supply unit, and a voltage display unit. The test electrode, the current-limiting resistor, the primary coil of the step-down transformer, and the touch electrode are connected in series. The secondary coil of the step-down transformer is connected to the electromagnetic coil and the power supply unit. The linear Hall is arranged opposite to the electromagnetic coil. The power supply unit is electrically connected to the linear Hall and the voltage display unit. The voltage display unit is electrically connected to the linear Hall.

[0008] By adopting the above technical solution, a circuit consisting of a test electrode, a current-limiting resistor, a step-down transformer's primary coil, and a hand-touch electrode connected in series can be used to generate a small, safe current from the voltage on the charged object to be tested, which is then introduced into the step-down transformer's primary coil. The voltage is then reduced and the current is amplified by the step-down transformer before being output through the secondary coil. An electromagnetic coil connected to the step-down transformer's secondary coil and a linear Hall effect device positioned opposite the electromagnetic coil can generate a highly stable induced magnetic field that is positively correlated with the output voltage of the secondary coil. The linear Hall effect device outputs a relatively stable output electrical signal, which is then displayed on a voltage display unit, improving the stability of the voltage display. A power supply unit connected to the step-down transformer's secondary coil can convert a portion of the current output by the secondary coil into AC / DC, generating a stable DC power supply for the linear Hall effect device and the voltage display unit. This eliminates the need for a power supply battery, reduces the size of the tester, saves battery replacement, and improves ease of use.

[0009] In a specific feasible implementation scheme, the power supply unit includes a rectifier module, a filter module and a voltage stabilizing module. The input end of the rectifier module is connected to the secondary coil of the step-down transformer, and the output end is connected to the filter module. The voltage stabilizing module is connected to the filter module, and the linear Hall and voltage display unit is connected to the output end of the voltage stabilizing module.

[0010] By adopting the above technical solution, the rectifier module can convert the AC power output by the secondary coil of the step-down transformer into DC power. After the ripple is filtered out by the filter module and the voltage is stabilized by the voltage regulator module, stable DC power is formed to ensure the normal operation of the linear Hall and voltage display units.

[0011] In a specific implementation scheme, the electromagnetic coil is connected to the output end of the filter module, and is connected to the secondary coil of the step-down transformer through the filter module and the rectifier module.

[0012] By adopting the above technical solution, a more stable magnetic field can be formed in the electromagnetic coil by utilizing the current after rectification by the rectifier module and filtering of the high-frequency ripple by the filter module. The larger inductance value of the electromagnetic coil can be utilized to reduce the step jump of the current and improve the stability of the voltage display value.

[0013] In a specific implementation scheme, the voltage display unit includes a signal processing module and an LCD display module. The signal processing module is connected to the signal output end of the linear Hall so as to extract the peak voltage of the fluctuation signal output by the linear Hall. The LCD display module is connected to the signal processing module so as to display the test electrode voltage value corresponding to the peak value of the linear Hall output voltage.

[0014] By adopting the above technical solution, the signal processing module is used to extract the peak value of the voltage of the linear Hall output signal. The peak value of the Hall signal can be used as the value of the voltage on the detected wire, reducing the influence of the voltage AC ripple on the voltage value displayed by the LCD display module and improving the stability of the voltage display value.

[0015] In a specific implementation scheme, the signal processing module is an MCU module, which samples the signal output end of the linear Hall and extracts the peak voltage, which is amplified and then transmitted to the LCD display module.

[0016] By adopting the above technical solution and using the MCU module sampling method to extract the voltage peak, the hardware circuit used is simpler, the circuit power consumption is lower, and the sampling frequency can be adjusted by software, so the accuracy of the extracted voltage peak is higher.

[0017] In a specific implementation scheme, the MCU module is an ultra-low power sensing and measurement microcontroller chip MSP430F4152.

[0018] By adopting the above technical solution and using the ultra-low power sensing and measurement microcontroller chip MSP430F4152 as the MCU module, a single chip can provide functions such as analog-to-digital conversion, peak voltage extraction, and display segment code conversion. The chip's operating current is at the microampere level, and the power consumption requirements can be met by detecting and sampling the small current, eliminating the need for an additional power supply and providing greater convenience.

[0019] In a specific implementation scheme, the Hall effect-based electrician tester of the present application also includes an electronic switch, which is a dual-channel single-pole double-throw analog switch. The current-limiting resistor includes a first resistor, a second resistor, a third resistor and a fourth resistor. The first resistor, the second resistor, the third resistor and the fourth resistor are connected in series with each other. The electronic switch is connected between the MCU module and the first resistor, the second resistor, the third resistor and the fourth resistor, so that the connection state between the first resistor, the second resistor, the third resistor and the fourth resistor can be controlled by the MCU module to form different equivalent resistance values.

[0020] By adopting the above technical solution, multiple resistors connected to the electronic switch can be switched in their connection mode to form current-limiting resistors with different equivalent resistance values. This allows for the extraction of relatively large current values ​​under different external voltages, ensuring the operating current requirements of the electromagnetic coil, linear Hall, and voltage display unit. By controlling the operation of the electronic switch using the MCU module, the resistance of the current-limiting resistor can be automatically reduced when the MCU power supply current is insufficient, increasing the sampling current and ensuring the current supply to the tester.

[0021] In a specific possible implementation scheme, the LCD display module uses a segmented liquid crystal screen.

[0022] By adopting the above technical solution, it is simpler to display and drive the voltage value using a segmented liquid crystal screen, and the power consumption of display and driving is also smaller.

[0023] In summary, this application includes at least one of the following beneficial technical effects:

[0024] 1. By providing a step-down transformer, the current collected from the charged object can be amplified. Thus, while obtaining a relatively small sampling current flowing through the human body, a larger current can be obtained to supply the relevant electronic components. This can meet the working requirements of the Hall effect-based voltage tester of this application without providing an external power supply battery.

[0025] 2. By setting up an electromagnetic coil to convert the sampled voltage into an electromagnetic field of corresponding magnitude, and using a linear Hall effect to generate a detection voltage signal proportional to the magnetic field strength, the inductance of the electromagnetic coil can be used to counteract the rapid changes in the sampled voltage signal, forming a highly stable electromagnetic field, thereby avoiding the voltage display value from being unclear due to rapid changes, and ensuring the stability of the detection value;

[0026] 3. By adopting a micro-power MCU integrated with an analog-to-digital conversion module and a segment code decoding circuit, it can realize signal shaping, analog-to-digital conversion, and segment code decoding functions under the support of a smaller operating current, reducing the size of the tester and improving the convenience of using the tester;

[0027] 4. By switching the equivalent resistance value of the current limiting resistor through the electronic switch, different current limiting resistors can be used when detecting charged bodies of different voltages, so that relatively high sampling current can be obtained under different detection voltages, ensuring the working current requirements of the detection circuit and the processing and display circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of an embodiment of the present application.

[0029] Figure 2 This is a circuit diagram of an embodiment of the present application.

[0030] Figure 3 This is a schematic diagram of the control principle of the electronic switch on the current limiting resistor in one embodiment of the present application.

[0031] Explanation of the accompanying symbols: 1. Test electrode; 2. Current limiting resistor; 3. Step-down transformer; 4. Hand touch electrode; 5. Electromagnetic coil; 6. Linear Hall; 7. Power supply unit; 71. Rectifier module; 72. Filter module; 73. Voltage stabilization module; 8. Voltage display unit; 81. Signal processing module; 82. LCD display module; 9. Electronic switch. DETAILED DESCRIPTION

[0032] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0034] An embodiment of the Hall effect-based test pen of the present application is as follows: Figure 1 and Figure 2 As shown, it includes a test electrode 1, a current limiting resistor 2, a step-down transformer 3, a hand touch electrode 4, an electromagnetic coil 5, a linear Hall 6, a power supply unit 7, and a voltage display unit 8. The test electrode 1 and the hand touch electrode 4 are respectively arranged at both ends of the test pencil, the current limiting resistor 2, the step-down transformer 3, the electromagnetic coil 5, the linear Hall 6, and the power supply unit 7 are arranged inside the test pencil, and the voltage display unit 8 is arranged on the wall of the test pencil.

[0035] Test electrode 1, current-limiting resistor 2, the primary coil of step-down transformer 3, and hand-touch electrode 4 are connected in series. When testing whether an external wire or electrical device, such as a charged object, is charged, test electrode 1 is brought into contact with the external charged object, and the tester's finger is brought into contact with hand-touch electrode 4. The voltage carried by the external charged object flows through test electrode 1, current-limiting resistor 2, the primary coil of step-down transformer 3, hand-touch electrode 4, and the tester, forming a weak current. The current flowing through the primary coil of step-down transformer 3 is then stepped down by the transformer, generating a larger current with a lower voltage in the secondary coil of step-down transformer 3.

[0036] The secondary coil of step-down transformer 3 is connected to electromagnetic coil 5 and power supply unit 7. A portion of the current flows into electromagnetic coil 5, generating a voltage-dependent magnetic field. Linear Hall 6 is positioned opposite electromagnetic coil 5. Linear Hall 6 is an analog Hall integrated circuit whose output voltage varies with the strength of the magnetic field.

[0037] The power supply unit 7 is electrically connected to the linear Hall sensor 6 and the voltage display unit 8. The current generated by the secondary coil of the step-down transformer 3 is processed by the power supply unit 7 to generate a DC regulated power supply with a constant voltage, which is used to power the linear Hall sensor 6 and the voltage display unit 8. The voltage display unit 8 is connected to the linear Hall sensor 6 and displays a value proportional to the voltage output by the linear Hall sensor 6. By adjusting the ratio of the value displayed by the voltage display unit 8 to the voltage output by the linear Hall sensor 6, the voltage display unit 8 can accurately display the voltage value of the charged object.

[0038] Thus, the Hall effect-based tester of the present application can not only detect whether a charged object is charged, but also accurately measure the magnitude of the voltage carried by the charged object, thereby accurately understanding the charged state of the charged object. Compared to existing testers that can only detect the voltage value of a charged object, the Hall effect-based tester of the present application is powered by the voltage carried by the external charged object. It does not require a separate power supply battery and does not need to worry about leakage caused by battery discharge, making it more convenient to use. Moreover, the larger inductance of the electromagnetic coil 5 can reduce step changes in the voltage on the charged object, thereby improving the stability of the displayed voltage value.

[0039] In some embodiments of the Hall effect-based test pencil of the present application, such as Figure 2 As shown, the power supply unit 7 includes a rectifier module 71, a filter module 72, and a voltage regulator module 73. The input of the rectifier module 71 is connected to the secondary coil of the step-down transformer 3. The current flowing through the primary coil of the step-down transformer 3 is amplified by the step-down transformer 3, and a high-current AC power is output from the secondary coil of the step-down transformer 3. The rectifier module 71 rectifies the AC power output from the secondary coil of the step-down transformer 3, converting it into pulsed DC power, which is output from the output of the rectifier module 71.

[0040] The filter module 72 is connected to the output of the rectifier module 71 to filter out the AC ripple in the pulsed DC power, forming a DC power with a stable voltage. The voltage regulator module 73 is connected to the filter module 72 to form a constant voltage output from the DC power output of the filter module 72.

[0041] The linear Hall sensor 6 and the voltage display unit 8 are connected to the output of the voltage stabilization module 73 and operate stably under the constant voltage output by the voltage stabilization module 73. The linear Hall sensor 6 consumes very little power, and the voltage display unit 8 also uses micro-power devices, enabling stable operation with a relatively low current supply. If the voltage of a charged object is too low to drive the voltage stabilization module 73 to the set constant voltage, the voltage tester will not display a specific voltage value, indicating that the voltage of the charged object is insufficient to affect the human body. It can be roughly assumed that the charged object being tested is not charged.

[0042] In a preferred embodiment of the Hall effect-based test pencil of the present application, Figure 2 As shown, the electromagnetic coil 5 is connected to the output end of the filter module 72. The alternating current output by the secondary coil of the step-down transformer 3 and stepped down by the step-down transformer 3 is rectified by the rectifier module 71 and filtered by the filter module 72 to form a direct current whose voltage value is proportional to the detected charged body voltage. The direct current passes through the electromagnetic coil 5, and forms a magnetic field at both ends of the electromagnetic coil 5 whose strength is proportional to the voltage of the direct current.

[0043] The electromagnetic coil 5 is wound with multiple turns of fine wire. By increasing the number of turns of the electromagnetic coil 5 and using a high-performance iron core, each milliampere of current flowing through the electromagnetic coil 5 can generate a magnetic field of 10Gs. Combined with the high-sensitivity linear Hall 6, it can effectively detect changes in the power supply voltage of the electromagnetic coil 5, thereby accurately detecting the voltage of the charged body.

[0044] In some embodiments of the Hall effect-based test pencil of the present application, such as Figure 2 As shown, the voltage display unit 8 includes a signal processing module 81 and an LCD display module 82. The signal processing module 81 is connected to the signal output terminal of the linear Hall sensor 6 and is used to extract and amplify the peak voltage of the fluctuation signal output by the linear Hall sensor 6. The LCD display module 82 is connected to the signal processing module 81 and is used to display the voltage value on the test electrode 1 corresponding to the peak value of the output voltage of the linear Hall sensor 6.

[0045] In a preferred embodiment of the Hall effect-based test pencil of the present application, Figure 2 As shown, the signal processing module 81 uses an MCU module, typically a micro-power MCU module. The output of the linear Hall effect 6 is directly connected to the MCU's ADC pin. The MCU is controlled by a program to complete the sampling, peak extraction, and proportional amplification of the output voltage of the linear Hall effect 6. After decoding by the MCU, the segment code is output to the LCD display, which displays the voltage value corresponding to the voltage of the charged object.

[0046] As a specific embodiment of the Hall effect-based voltage tester of this application, the MCU module uses the ultra-low-power sensing and measurement microcontroller chip MSP430F4152. The MSP430F4152 chip consumes 220 microamperes in active mode and 0.9 microamperes in standby mode. It integrates an IrDA encoder and decoder, an integrated LCD driver with up to 144 contrast control levels, and a power supply voltage monitor with programmable level detection. This facilitates sampling, peak extraction, proportional amplification, decoding, and LCD driving of the linear Hall effect 6 output voltage, enabling microampere-level drive of the LCD screen and ensuring the normal operation of the signal processing module 81 and LCD display module 82 with minimal current.

[0047] In a preferred embodiment of the Hall effect-based test pencil of the present application, Figure 2 and Figure 3 As shown, the tester also includes an electronic switch 9, which uses a dual-channel single-pole double-throw analog switch, specifically the low-power SGM3005XMS. The current-limiting resistor 2 is composed of a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4 connected in series. The electronic switch 9 is connected between the MCU module and the first, second, third, and fourth resistors R1, R2, R3, and R4. The MCU module monitors the current state of the power supply. When the power supply current is insufficient, it generates a control signal to control the on / off state of the internal circuit of the electronic switch 9, switching the connection state between the first, second, third, and fourth resistors R1, R2, R3, and R4, thereby reducing the equivalent resistance of the current-limiting resistor 2. When the charged voltage of the charged body is low, the current through the primary coil of the step-down transformer 3 is increased, ensuring that the output current of the power supply unit 7 meets the operating requirements of the electromagnetic coil 5, the linear Hall 6, and the voltage display unit 8.

[0048] A specific setting method of the electronic switch and the current limiting resistor is as follows: Figure 3 As shown, end a of the current-limiting resistor 2 is connected to the test electrode 1 for contact with an external charged object; end b of the current-limiting resistor 2 is connected to the primary coil of the step-down transformer 3. A first resistor R1, a second resistor R2, a third resistor R2, and a fourth resistor R4 are connected in series from end a of the current-limiting resistor 2 to end b of the current-limiting resistor 2. The first resistor R1 is connected between the common terminal COM1 pin of the first switch in the electronic switch 9 and the normally closed contact NC1 pin of the first switch; one end of the second resistor R2 is connected simultaneously to the common terminal COM1 pin of the first switch in the electronic switch 9 and the normally open contact NO2 pin of the second switch, and the other end is connected to the normally open contact NO1 pin of the first switch; the third resistor R3 is connected between the common terminal COM2 pin of the second switch in the electronic switch 9 and the normally open contact NO1 pin of the first switch; and the fourth resistor R4 is connected between the common terminal COM2 pin of the second switch in the electronic switch 9 and the normally closed contact NC2 pin of the second switch. The control terminal IN1 of the first switch and the control terminal IN2 of the second switch in the electronic switch 9 are respectively connected to the MCU module.

[0049] Specifically, the resistance of the first resistor R1 is 250K, the resistance of the second resistor R2 is 1250K, the resistance of the third resistor R3 is 750K, and the resistance of the fourth resistor R4 is 250K. In the default state, the COM1 pin and the NC1 pin are short-circuited inside the electronic switch 9, short-circuiting the two ends of the first resistor R1; the COM2 pin and the NC2 pin are short-circuited, short-circuiting the two ends of the fourth resistor R4. The current-limiting resistor 2 is equivalent to the second resistor R2 and the third resistor R3 connected in series, with a resistance of 2M. When detecting a charged object with a voltage of 500-1000V, a current of 0.25-0.5mA can be generated in the primary coil of the step-down transformer 3. Without causing any human sensation, the voltage is reduced tenfold by the step-down transformer 3, and at least a 50V2.5mA electrical output is generated in the secondary coil of the step-down transformer 3, which can meet the working requirements of the electromagnetic coil 5, the linear Hall 6, and the voltage display unit 8.

[0050] When the power supply voltage of the charged object is lower than 500V, the output current of the power supply unit 7 will drop. Once the MCU module power supply voltage drops, the power supply voltage monitor detects the power supply voltage drop and outputs a control signal to the IN1 pin of the electronic switch 9, controlling the internal COM1 pin of the electronic switch 9 to disconnect the NC1 pin and short-circuit the NO1 pin, while the COM2 pin and the NC2 pin remain short-circuited. At this time, the second resistor R2 and the fourth resistor R4 are short-circuited, and the current-limiting resistor 2 is equivalent to the first resistor R1 and the third resistor R3 in series, with a resistance of 1M. When detecting a charged object with a voltage of 250-500V, a current of 0.25-0.5mA can also be generated in the primary coil of the step-down transformer 3. Under the premise of not causing human sensation, after the ten-fold voltage reduction of the step-down transformer 3, at least 25V2.5mA of electrical output is generated in the secondary coil of the step-down transformer 3, which can meet the working requirements of the electromagnetic coil 5, the linear Hall 6 and the voltage display unit 8.

[0051] When the power supply voltage of a charged object is lower than 250V, the current output by the power supply unit 7 will decrease. Once the MCU module power supply voltage drops, the power supply voltage monitor detects the power supply voltage drop and then outputs a control signal to the IN2 pin of the electronic switch 9, controlling the internal COM2 pin of the electronic switch 9 to disconnect from the NC2 pin and short-circuit with the NO2 pin, while the COM1 pin and the NO1 pin remain short-circuited. At this time, the second resistor R2 and the third resistor R3 are short-circuited, and the current-limiting resistor 2 is equivalent to the first resistor R1 and the fourth resistor R4 connected in series, with a resistance of 500K. When detecting a charged object with a voltage of 125-250V, a current of 0.25-0.5mA can also be generated in the primary coil of the step-down transformer 3. Without causing any human sensation, after the ten-fold voltage reduction of the step-down transformer 3, at least 12.5V2.5mA of electrical output is generated in the secondary coil of the step-down transformer 3, which can meet the working requirements of the electromagnetic coil 5, the linear Hall 6, and the voltage display unit 8.

[0052] When the power supply voltage of a charged object falls below 125V, the output current of power supply unit 7 decreases. Once the MCU module's power supply voltage drops, the power supply voltage monitor detects the drop and cancels the control signal output to pin IN1 of electronic switch 9. This disconnects pin COM1 from pin NO1 and short-circuits pin NC1, while pin COM2 remains short-circuited from pin NO2. At this point, the two ends of the first resistor R1 are short-circuited, and the two ends of the series circuit formed by the second resistor R2 and the third resistor R3 are short-circuited. Current-limiting resistor 2 is equivalent to the fourth resistor R4, with a resistance of 250K. When detecting a charged object with a voltage of 50-125V, a current of 0.2-0.5mA can be generated in the primary coil of step-down transformer 3. Without causing human sensation, the voltage is reduced tenfold by the step-down transformer 3, generating at least a 5V2mA electrical output in the secondary coil of the step-down transformer 3, which can meet the operating requirements of the electromagnetic coil 5, linear Hall 6, and voltage display unit 8.

[0053] This ensures that the Hall-effect-based tester of the present application can utilize the charge carried by the external charged object to power the internal electronic components of the tester when detecting a charged object with a 50-1000V power supply, allowing the tester to measure the voltage of the charged object without a battery, while also preventing discomfort to the human body caused by the current flowing through the charged object. The Hall-effect-based tester of the present application has difficulty detecting charged objects with voltages below 50V and generally deems them to be uncharged. Voltages below 50V generally do not pose a danger to the human body and do not affect the practical use of the Hall-effect-based tester of the present application.

[0054] In some embodiments of the Hall-effect-based voltage tester of the present application, the LCD display module 82 includes an analog-to-digital conversion circuit, a decoding circuit, and a seven-segment LCD display. The analog-to-digital conversion circuit is connected to the signal processing module 81 and is used to convert the linear Hall effect 6 output voltage, after being processed, amplified, and processed by the signal processing module 81, into a digital signal corresponding to the voltage value. The decoding circuit is connected to the analog-to-digital conversion circuit and is used to convert the digital voltage signal into a display segment code. The seven-segment LCD display is connected to the decoding circuit and displays the specific voltage value on the LCD according to the display segment code.

[0055] The analog-to-digital conversion circuit and the decoding circuit can use independent integrated circuit chips, or they can use a single integrated circuit chip. Alternatively, they can share a single integrated circuit chip with the signal processing module 81 that integrates the corresponding functions. However, low-power or micro-power integrated circuit chips are preferred. The LCD display can use a three-digit seven-segment LCD display. The current consumption of a low-power three-digit seven-segment LCD display is less than 5 microamperes, which helps reduce the overall current consumption of the tester.

[0056] Throughout the description of this application, reference to terms such as "one embodiment," "specific embodiment," and "preferred embodiment" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of this application. In this application, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0057] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A Hall effect-based test pencil, characterized in that: The invention comprises a test electrode (1), a current limiting resistor (2), a step-down transformer (3), a hand-touch electrode (4), an electromagnetic coil (5), a linear Hall (6), a power supply unit (7) and a voltage display unit (8), wherein the test electrode (1), the current limiting resistor (2), the primary coil of the step-down transformer (3) and the hand-touch electrode (4) are connected in series, the secondary coil of the step-down transformer (3) is connected to the electromagnetic coil (5) and the power supply unit (7), the linear Hall (6) and the electromagnetic coil (5) are arranged opposite to each other, the power supply unit (7) is electrically connected to the linear Hall (6) and the voltage display unit (8), and the voltage display unit (8) is electrically connected to the linear Hall (6).

2. The Hall effect-based electric tester according to claim 1, characterized in that: The power supply unit (7) comprises a rectifier module (71), a filter module (72) and a voltage stabilizing module (73); the input end of the rectifier module (71) is connected to the secondary coil of the step-down transformer (3), and the output end is connected to the filter module (72); the voltage stabilizing module (73) is connected to the filter module (72); and the linear Hall (6) and the voltage display unit (8) are connected to the output end of the voltage stabilizing module (73).

3. The Hall effect-based electric tester according to claim 2, characterized in that: The electromagnetic coil (5) is connected to the output end of the filter module (72), and is connected to the secondary coil of the step-down transformer (3) through the filter module (72) and the rectifier module (71).

4. The Hall effect-based electric tester according to claim 1, characterized in that: The voltage display unit (8) includes a signal processing module (81) and an LCD display module (82). The signal processing module (81) is connected to the signal output end of the linear Hall (6) so as to extract the peak voltage of the fluctuation signal output by the linear Hall (6). The LCD display module (82) is connected to the signal processing module (81) so as to display the voltage value of the test electrode (1) corresponding to the peak value of the output voltage of the linear Hall (6).

5. The Hall effect-based electric tester according to claim 4, characterized in that: The signal processing module (81) is an MCU module, which samples the signal output end of the linear Hall (6) through the MCU module, extracts the peak voltage, amplifies it, and transmits it to the LCD display module (82).

6. The Hall effect-based electric tester according to claim 5, characterized in that: The MCU module is an ultra-low power sensing and measurement microcontroller chip MSP430F4152.

7. The Hall effect-based electric tester according to claim 5, characterized in that: The electronic switch (9) is a dual-channel single-pole double-throw analog switch. The current-limiting resistor (2) comprises a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor, the second resistor, the third resistor, and the fourth resistor are connected in series. The electronic switch (9) is connected between the MCU module and the first resistor, the second resistor, the third resistor, and the fourth resistor so that the connection state between the first resistor, the second resistor, the third resistor, and the fourth resistor can be controlled by the MCU module to form different equivalent resistance values.

8. The Hall effect-based electric tester according to claim 4, characterized in that: The LCD display module (82) adopts a segmented liquid crystal screen.

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