Double display power meter for laboratory table

Abstract

The present application belongs to the technical field of ammeter, and discloses a double-display power ammeter for experiment table, which comprises an experiment table, an integrated power supply box fixedly connected to one side of the lower end of the experiment table, and a strip-shaped clamping seat fixedly connected to the upper end of the experiment table, further comprising: an experimental measurement power component installed on the strip-shaped clamping seat, which comprises an ammeter main body; the structure cooperation of the inner shaft ring, the outer shaft ring, the transparent anti-misconnection surface ring, the wiring opening and the outer pointer hand shaft is set, the outer pointer hand shaft drives the inner shaft ring, the outer shaft ring and the transparent anti-misconnection surface ring to rotate, the wiring opening on the transparent anti-misconnection surface ring is only open when it is aligned with the correct wiring point, and shields the redundant wiring position when it deviates from the correct point, effectively avoiding the damage of the instrument caused by the students' misconnection of the range and the wrong connection of the wiring column, solving the problem that the existing ammeter is easy to be burned due to misoperation, and improving the safety and standardization of the experimental operation.

Description

Technical Field

[0001] This invention belongs to the field of ammeter technology, specifically a dual-display power meter for laboratory benchtops. Background Technology

[0002] In physics experiments for students, ammeters are commonly used measuring instruments, mainly used to detect the magnitude of current in circuits. The dual-display power meter on the experimental table is a current measuring instrument designed specifically for physics teaching experiments. Its core feature is that it has two display modes or two ranges, which makes it easy for students to observe, compare and learn the principle of current measurement intuitively. Its core feature is that it has both a pointer dial and a digital display screen or a combination of a single pointer and dual scales.

[0003] For example, CN202351314U discloses an ammeter device for teaching experiments, comprising: a display circuit module; a power supply module, the output of which is connected to the display module for supplying power to the display circuit module; a conversion circuit module, connected in parallel with the power supply module, the output of which is connected to the display circuit module for converting AC voltage into DC voltage for output; and a switching module, the input of which is connected to the power grid, and the output of which is connected to the inputs of both the power supply module and the conversion circuit module for switching the circuit between the power supply module and the conversion circuit module. This device can be used to switch the circuit between the power supply module and the conversion circuit module. By manually controlling the operation of the switching circuit module, the changes in current affecting the ammeter display can be intuitively understood, facilitating teaching use, and featuring a simple structure and high safety.

[0004] While the above-mentioned solution is convenient for teaching and has a simple structure with high safety, the existing dual-display power meters on the experimental table have potential risks of misoperation during actual use. Specifically, students often lack operational proficiency and frequently connect the wrong terminals after switching current ranges. The terminals of the existing ammeters are usually exposed, and all terminals remain pluggable regardless of range switching, lacking corresponding shielding structures to prevent misconnection. This makes it difficult for students to connect wires to terminals that are incompatible with the current range, leading to overload of the instrument's internal circuitry, burnout, and other malfunctions. This not only damages the instrument and increases the maintenance costs of teaching equipment but may also affect the normal conduct of experiments. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a dual-display power meter for laboratory tables.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dual-display power meter for an experimental table, comprising an experimental table, characterized in that: an integrated power supply box is fixedly connected to one side of the lower end of the experimental table, and a strip-shaped mounting base is fixedly connected to the upper end of the experimental table, and further comprising: an experimental measurement power component installed on the strip-shaped mounting base; The experimental power measurement component includes an ammeter body, with a mounting block fixedly connected to the lower end of the ammeter body and engaging with a strip-shaped mounting base. A digital display panel for displaying measurement values ​​is fixedly connected to the upper side of one end of the ammeter body. An arc-shaped range scale mark is fixedly connected to the side of the ammeter body near the digital display panel. A negative terminal, a small-range positive terminal, and a large-range positive terminal are fixedly connected to the front end of the ammeter body, located below the inner pointer shaft. The component also includes an inner pointer shaft, an outer pointer grip shaft, and a foolproof component. The inner pointer shaft is rotatably mounted on the ammeter body and is driven to deflect by the measured current to indicate the measured value. The outer pointer hand grip shaft is rotatably sleeved on the outside of the inner pointer shaft and has no mechanical transmission connection with the inner pointer shaft. It is used for manual rotation to switch the range. The foolproof component is linked to the outer pointer grip shaft and includes an inner shaft ring and an outer shaft ring fixedly connected to the outer pointer grip shaft, as well as a transparent anti-misconnection face ring connected between the inner shaft ring and the outer shaft ring. The transparent anti-misconnection face ring has multiple wiring openings.

[0007] Preferably, the negative terminal, the small-range positive terminal, and the large-range positive terminal are arranged in an arc shape, and the center of their arrangement coincides with the rotation axis of the external pointer grip shaft. The positions of the multiple wiring openings correspond one-to-one with the positions of the negative terminal, the small-range positive terminal, and the large-range positive terminal.

[0008] Preferably, the plurality of wiring openings are distributed at unequal angles along the circumferential direction of the transparent anti-misconnection face ring, and the interval angles are respectively matched with the actual distribution angles between the negative terminal, the small-range positive terminal, and the large-range positive terminal, so that only the corresponding wiring positions are exposed when the external pointer hand grips the shaft and rotates to different range positions.

[0009] Preferably, the transparent anti-misconnection face ring has multiple reinforcing ribs fixedly connected inside. The multiple reinforcing ribs extend radially along the transparent anti-misconnection face ring and intersect each other in a star shape, which is used to enhance the torsional stiffness of the transparent anti-misconnection face ring while maintaining its transparency.

[0010] Preferably, a flexible anti-collision strip is fixedly connected to the open end of the wiring opening, and the flexible anti-collision strip is made of silicone or rubber.

[0011] Preferably, an auxiliary protection component is provided at one end of the outer shaft ring near the ammeter body. The auxiliary protection component includes a connecting ring fixedly connected to the side of the outer shaft ring and the wiring opening. Several flexible back curtain strips are fixedly connected to one end of the connecting ring near the ammeter body.

[0012] Preferably, the flexible back curtain strip is a plurality of parallel strips of soft plastic sheet, and there is partial overlap between adjacent flexible back curtain strips.

[0013] Preferably, the transparent anti-misconnection face ring is made of transparent polycarbonate plastic, which is used to observe the internal alignment while blocking the non-corresponding wiring position.

[0014] Preferably, the outline shape of the wiring opening is any one of rectangle, waist shape or arc shape, and the width is greater than the outer diameter of the terminal block, so as to allow the insertion of electrical wire plugs.

[0015] Preferably, the outer circumferential surface of the outer shaft ring is provided with a plurality of anti-slip ridges evenly distributed along the circumference, which are used to increase the friction when the hand grips the shaft to manually rotate the outer pointer.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a structure consisting of an inner shaft ring, an outer shaft ring, a transparent anti-misconnection face ring, a wiring opening, and an external pointer grip shaft. The external pointer grip shaft rotates the inner shaft ring, the outer shaft ring, and the transparent anti-misconnection face ring. The wiring opening on the transparent anti-misconnection face ring is only open when aligned with the correct wiring point; it blocks extra wiring positions when the connection deviates from the correct point. This effectively prevents instrument damage caused by students misconnecting the range or incorrectly connecting the terminals, solves the problem of existing ammeters easily burning out due to misoperation, and improves the safety and standardization of experimental operations. This invention features an external pointer hand grip shaft for easy and stable range switching by the operator, an internal pointer shaft with arc-shaped range scale markings for mechanical reading, and a digital display panel that displays the digital reading simultaneously for easy comparison and calibration to improve measurement accuracy. The combination of the bar-shaped mounting base and the mounting block allows for the detachable fixing of the ammeter body, facilitating later maintenance and position adjustment, thus taking into account both teaching needs and practical convenience. This invention utilizes a combination of reinforcing ribs, flexible anti-collision strips, connecting rings, and flexible back curtain strips. The reinforcing ribs provide structural support for the transparent anti-misconnection face ring, preventing it from deforming and breaking during rotation. The flexible anti-collision strips prevent hard collisions between the wires and the edge of the wiring opening, thus protecting the wires and the wiring opening structure. The connecting rings drive the flexible back curtain strips to fit the ammeter body and avoid protruding parts, improving the overall ease of operation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the experimental platform of the present invention; Figure 2 This is a schematic diagram of the strip-shaped card holder structure of the present invention; Figure 3 This is a schematic diagram of the structure of the power component used in the experimental measurement of this invention; Figure 4 This is a schematic diagram of the error-proof component structure of the present invention; Figure 5 This is a schematic diagram of the auxiliary protection component structure of the present invention; Figure 6 This is a schematic diagram of the rotating state structure of the transparent anti-misconnection face ring of the present invention.

[0018] In the diagram: 1. Experimental platform; 2. Integrated power supply box; 3. Strip-shaped mounting bracket; 4. Experimental measurement power assembly; 400. Ammeter body; 401. Mounting block; 402. Digital display panel; 5. Arc-shaped range scale markings; 6. Inner pointer shaft; 7. Outer pointer grip shaft; 8. Negative terminal; 9. Small range positive terminal; 10. Large range positive terminal; 11. Foolproof component; 1100. Inner shaft ring; 1101. Outer shaft ring; 1102. Transparent anti-misconnection face ring; 1103. Wiring opening; 1104. Reinforcing rib; 1105. Flexible anti-collision strip; 12. Auxiliary protection component; 1200. Connecting ring; 1201. Flexible back curtain strip. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figures 1 to 6 As shown, the present invention provides a dual-display power meter for an experimental table, including an experimental table 1, an integrated power supply box 2 fixedly connected to one side of the lower end of the experimental table 1, a strip-shaped mounting base 3 fixedly connected to the upper end of the experimental table 1, and further including: an experimental measurement power assembly 4 installed on the strip-shaped mounting base 3, the experimental measurement power assembly 4 including an ammeter body 400, a mounting block 401 fixedly connected to the lower end of the ammeter body 400 and engaging with the strip-shaped mounting base 3, a digital display panel 402 for displaying measurement values ​​fixedly connected to the upper side of one end of the ammeter body 400, an arc-shaped range scale mark 5 fixedly connected to the side of the ammeter body 400 near the digital display panel 402, and a negative terminal 8, a small range positive terminal 9, and a large range positive terminal 10 fixedly connected to the front end of the ammeter body 400 below the inner pointer shaft 6, and further including an inner pointer shaft 6, an outer pointer grip shaft 7, and a foolproof component 11; The inner pointer shaft 6 is rotatably mounted on the ammeter body 400 and is driven to deflect by the measured current to indicate the measured value. The outer pointer hand grip shaft 7 is rotatably sleeved on the outside of the inner pointer shaft 6 and has no mechanical transmission connection with the inner pointer shaft 6. It is used for manual rotation to switch the range. The foolproof component 11 is linked with the outer pointer grip shaft 7 and includes an inner shaft ring 1100 and an outer shaft ring 1101 fixedly connected to the outer pointer grip shaft 7, and a transparent anti-misconnection face ring 1102 connected between the inner shaft ring 1100 and the outer shaft ring 1101. The transparent anti-misconnection face ring 1102 has multiple wiring openings 1103.

[0021] The above scheme adopts a separate sleeve structure for the outer pointer hand grip shaft 7 and the inner pointer rotating shaft 6, with no mechanical transmission connection between them. This allows the anti-foolproof component 11 to move synchronously by manually rotating the outer pointer hand grip shaft 7, without interfering with the normal deflection of the inner pointer rotating shaft 6. This ensures that the inner pointer rotating shaft 6 can accurately fit the arc-shaped range scale mark 5 to indicate the measurement value under the drive of the measured current, thus guaranteeing the accuracy of the measurement results.

[0022] The negative terminal 8, the small-range positive terminal 9, and the large-range positive terminal 10 are arranged in an arc shape, and the center of their arrangement coincides with the rotation axis of the external pointer grip shaft 7. The positions of multiple wiring openings 1103 correspond one-to-one with the positions of the negative terminal 8, the small-range positive terminal 9, and the large-range positive terminal 10. These openings 1103 are spaced at unequal angles along the circumference of the transparent anti-misconnection ring 1102, with the angles corresponding to the actual distances between the negative terminal 8, the small-range positive terminal 9, and the large-range positive terminal 10. The fabric angle is matched so that when the external pointer hand grips the shaft 7 and rotates to different range positions, only the corresponding wiring position is exposed. Multiple reinforcing ribs 1104 are fixedly connected inside the transparent anti-misconnection face ring 1102. The multiple reinforcing ribs 1104 extend radially along the transparent anti-misconnection face ring 1102 and intersect each other in a star shape. This is used to enhance the torsional rigidity of the transparent anti-misconnection face ring 1102 while maintaining its transparency. A flexible anti-collision strip 1105 is fixedly connected to the open end of the wiring opening 1103. The flexible anti-collision strip 1105 is made of silicone or rubber.

[0023] The above-mentioned solution is adopted: the multiple reinforcing ribs 1104 fixedly connected inside the transparent anti-misconnection face ring 1102 do not simply extend radially, but intersect at the central axis, forming a fixed angle between each reinforcing rib, and forming a cross-shaped distribution pattern. This cross-shaped layout makes the stress points of the transparent anti-misconnection face ring 1102 evenly distributed along the circumferential direction, and can transfer the torsional load generated during rotation to the inner shaft ring 1100 and the outer shaft ring 1101 along the reinforcing ribs, avoiding stress concentration on the body material of the transparent anti-misconnection face ring 1102.

[0024] An auxiliary protection component 12 is provided at one end of the outer shaft ring 1101 near the ammeter body 400. The auxiliary protection component 12 includes a connecting ring 1200 fixedly connected to one side of the outer shaft ring 1101 and the wiring opening 1103. Several flexible back curtain strips 1201 are fixedly connected at one end of the connecting ring 1201 near the ammeter body 400. The flexible back curtain strips 1201 are multiple parallel strips of soft plastic sheets, and the adjacent flexible back curtain strips 1201 partially overlap. The transparent anti-misconnection face ring 1102 is made of transparent polycarbonate plastic and is used to observe the internal alignment while blocking the non-corresponding wiring position. The outline shape of the wiring opening 1103 is any one of rectangle, waist shape or arc shape, and the width is greater than the outer diameter of the terminal block to allow the insertion of electrical wire plugs. Multiple anti-slip ridges are provided on the outer circumferential surface of the outer shaft ring 1101, which are evenly distributed in the circumferential direction to increase the friction when the hand holds the shaft 7 to manually rotate the outer pointer.

[0025] The above scheme is adopted: the flexible back curtain strip 1201 is a series of parallel strip-shaped soft plastic sheets. Each back curtain strip is arranged at equal intervals along the arc surface of the connecting ring 1200. The adjacent flexible back curtain strips are arranged in a layered and partially overlapping manner, that is, the side of each back curtain strip covers part of the side of the adjacent back curtain strip, forming a multi-layered overlapping structure similar to fish scales. When the auxiliary protection component 12 rotates as a whole with the outer shaft ring 1101, the end of the flexible back curtain strip 1201 always adheres to the outer wall surface of the ammeter body 400 and slides on the wall surface.

[0026] The following is a supplementary explanation of the specific electronic component models and configuration relationships of the electrical measurement module inside the ammeter body 400: The ammeter body 400 is equipped with a main control circuit board, which integrates a microcontroller unit and an energy metering chip electrically connected to it. The digital display panel 402 adopts an LCD segment display module. The integrated power supply box 2 is equipped with a switching power supply module to power the main control circuit board and the digital display panel respectively.

[0027] Working principle and usage process of this invention: An integrated power supply box 2 is installed on one side of the lower end of the experimental platform 1. The integrated power supply box 2 provides a stable power supply for the experimental measurement power component 4. A strip-shaped mounting base 3 is fixedly installed on the upper end of the experimental platform 1. The strip-shaped mounting base 3 has a slot that matches the mounting block 401. The ammeter body 400 is embedded into the slot of the strip-shaped mounting base 3 with the help of the bottom mounting block 401, so as to complete the detachable fixation of the overall position of the experimental measurement power component 4, which is convenient for subsequent disassembly, maintenance and position adjustment. The operator selects the corresponding wire to conduct the experiment according to the current range required by the experiment. The operator manually rotates the outer pointer handle 7 to select the corresponding range, such as a small range of 0.6A or a large range of 3A, based on the estimated magnitude of the current to be measured. Since the outer pointer handle 7 is rotatably fitted onto the outside of the inner pointer shaft 6, and there is no mechanical transmission connection between them, the rotation of the outer pointer handle 7 does not cause the inner pointer shaft 6 to rotate. The inner pointer shaft 6 remains in a free state, and its measuring pointer points to zero when no power is applied. Simultaneously with the rotation of the outer pointer handle 7, the inner shaft ring 1100, outer shaft ring 1101, and transparent anti-misconnection face ring 1102, which are fixedly connected to it, rotate synchronously. The transparent anti-misconnection face ring 1102 has multiple wiring openings 1103, the positions of which correspond to the negative terminal 8, the small range positive terminal 9, and the large range positive terminal 10, respectively. Since the wiring openings 1103 are distributed at unequal angles along the circumference, and their interval angle matches the actual distribution angle between each terminal, therefore: When the external pointer is rotated to the small range position by holding the shaft 7, the wiring opening 1103 is exactly aligned with the negative terminal 8 and the small range positive terminal 9 at the same time, while the large range positive terminal 10 is completely blocked by the solid part of the transparent anti-misconnection face ring 1102. When the external pointer is rotated to the large range position by holding the shaft 7, the wiring opening 1103 is exactly aligned with the negative terminal 8 and the large range positive terminal 10 at the same time, while the small range positive terminal 9 is blocked.

[0028] At this point, the operator can only insert the wire into the exposed correct wiring position and cannot connect it to the blocked incorrect wiring position, thus physically preventing instrument overload or damage caused by incorrect wiring position after range switching.

[0029] After completing the wiring, close the experimental circuit. The measured current flows into the measuring mechanism inside the ammeter body 400 through the terminals, driving the inner pointer shaft 6 to deflect independently and freely. The pointer on the inner pointer shaft 6 indicates the mechanical reading on the arc-shaped range scale mark 5. At the same time, the digital display panel 402 displays the digital current value, which is convenient for operators to compare and calibrate, and improves the measurement accuracy. After the experiment, disconnect the circuit. The inner pointer shaft 6 returns to the zero position by the restoring force of the hairspring. The operator can hold the outer pointer shaft 7 and rotate it to any position or neutral without affecting the next use of the instrument. The transparent anti-misconnection ring 1102 has a cross-shaped reinforcing rib 1104 inside, one end of which is connected to the inner wall of the transparent anti-misconnection ring 1102, and the other end is connected to the inner shaft ring 1100 and the outer shaft ring 1101 respectively. It continuously provides structural support for the transparent anti-misconnection ring 1102, disperses the stress generated when the transparent anti-misconnection ring 1102 rotates, stabilizes the overall shape of the transparent anti-misconnection ring 1102 during rotation, and prevents it from deforming or breaking. The flexible anti-collision strip 1105 set at the end of the wiring opening 1103 prevents the wire from having a hard collision with the edge of the wiring opening 1103 when students install wires. During the rotation and movement of the outer shaft ring 1101, the end of it close to the ammeter body 400 drives the connecting ring 1200 to move synchronously through the buckle. After the connecting ring 1200 is subjected to force, it pulls the flexible back curtain 1201 fixedly connected to it to undergo flexible deformation. During the deformation of the flexible back curtain 1201, its surface adheres to the outer wall of the ammeter body 400, while avoiding hard contact with protruding parts such as the digital display panel 402 and the arc-shaped range scale mark 5.

[0030] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0031] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-display power meter for an experimental table, comprising an experimental table (1), characterized in that: An integrated power supply box (2) is fixedly connected to one side of the lower end of the experimental platform (1), and a strip-shaped mounting base (3) is fixedly connected to the upper end of the experimental platform (1). It also includes an experimental measurement power assembly (4) installed on the strip-shaped mounting base (3). The experimental power measurement component (4) includes an ammeter body (400), a mounting block (401) that engages with a strip mounting base (3) is fixedly connected to the lower end of the ammeter body (400), a digital display panel (402) for displaying measurement values ​​is fixedly connected to the upper side of one end of the ammeter body (400), an arc-shaped range scale mark (5) is fixedly connected to the side of the ammeter body (400) near the digital display panel (402), and a negative terminal (8), a small range positive terminal (9), and a large range positive terminal (10) located below the inner pointer shaft (6) are fixedly connected to the front end of the ammeter body (400). It also includes an inner pointer shaft (6), an outer pointer grip shaft (7), and a foolproof component (11). The inner pointer shaft (6) is rotatably mounted on the ammeter body (400) and is driven to deflect by the measured current to indicate the measured value. The outer pointer hand grip shaft (7) is rotatably mounted on the outside of the inner pointer shaft (6) and has no mechanical transmission connection with the inner pointer shaft (6). It is used for manual rotation to switch the range. The foolproof component (11) is linked with the outer pointer grip shaft (7) and includes an inner shaft ring (1100) and an outer shaft ring (1101) fixedly connected to the outer pointer grip shaft (7), and a transparent anti-misconnection face ring (1102) connected between the inner shaft ring (1100) and the outer shaft ring (1101). The transparent anti-misconnection face ring (1102) has multiple wiring openings (1103).

2. The dual-display power meter for the experimental table according to claim 1, characterized in that: The negative terminal (8), the small-range positive terminal (9), and the large-range positive terminal (10) are arranged in an arc shape, and the center of their distribution coincides with the rotation axis of the external pointer hand grip shaft (7). The positions of the multiple wiring openings (1103) correspond one-to-one with the positions of the negative terminal (8), the small-range positive terminal (9), and the large-range positive terminal (10).

3. The dual-display power meter for the experimental table according to claim 1, characterized in that: Multiple wiring openings (1103) are distributed at unequal angles along the circumference of the transparent anti-misconnection face ring (1102). The interval angles are respectively matched with the actual distribution angles between the negative terminal (8), the small range positive terminal (9), and the large range positive terminal (10), so that only the corresponding wiring positions are exposed when the external pointer hand grip shaft (7) is rotated to different range positions.

4. The dual-display power meter for the experimental table according to claim 1, characterized in that: The transparent anti-misconnection face ring (1102) is fixedly connected with multiple reinforcing ribs (1104). The multiple reinforcing ribs (1104) extend radially along the transparent anti-misconnection face ring (1102) and intersect each other in a cross shape, which is used to enhance the torsional stiffness of the transparent anti-misconnection face ring (1102) while maintaining its transparency.

5. The dual-display power meter for the experimental table according to claim 1, characterized in that: The open end of the wiring opening (1103) is fixedly connected to a flexible anti-collision strip (1105), which is made of silicone or rubber.

6. The dual-display power meter for the experimental table according to claim 1, characterized in that: An auxiliary protection component (12) is provided at one end of the outer shaft ring (1101) near the ammeter body (400). The auxiliary protection component (12) includes a connecting ring (1200) fixedly connected to one side of the outer shaft ring (1101) and the wiring opening (1103). Several flexible back curtain strips (1201) are fixedly connected to one end of the connecting ring (1200) near the ammeter body (400).

7. The dual-display power meter for the experimental table according to claim 6, characterized in that: The flexible back curtain strip (1201) consists of multiple parallel strips of soft plastic sheets, with some overlap between adjacent flexible back curtain strips (1201).

8. The dual-display power meter for the experimental table according to claim 1, characterized in that: The transparent anti-misconnection face ring (1102) is made of transparent polycarbonate plastic and is used to observe the internal alignment while blocking non-corresponding wiring positions.

9. The dual-display power meter for the experimental table according to claim 1, characterized in that: The outline shape of the wiring opening (1103) is any one of rectangle, waist shape or arc shape, and the width is greater than the outer diameter of the terminal block, so as to allow the insertion of electrical wire plugs.

10. The dual-display power meter for the experimental table according to claim 1, characterized in that: The outer circumferential surface of the outer shaft ring (1101) is provided with multiple anti-slip ridges evenly distributed along the circumference, which are used to increase the friction when the hand grips the shaft (7) to manually rotate the outer pointer.

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