A miniature surge protection module based on digitized meter

Abstract

This utility model discloses a miniature surge protection module based on digital meters, including an assembly shell. The assembly shell is a square shell, and one side of the assembly shell has a connecting end. A front connector is threaded to the outer periphery of the connecting end. An installation chamber is formed inside the assembly shell. A limit ring is provided on the inner wall of the installation chamber, and an installation notch is provided on the limit ring. A top protrusion is provided on the top of the assembly shell. A circuit board is vertically arranged within the installation notch, and a tail shell is threaded to the top protrusion. The beneficial effect provided by this utility model is that it solves the technical problem that the overall size of the surge protection module in the prior art is large, resulting in a cumbersome installation process and high requirements for the installation environment.

Description

Technical Field

[0001] This utility model relates to the field of electrical equipment technology, specifically to a miniature surge protection module based on digital meters. Background Technology

[0002] Instrument surge protection modules, as key components in the field of electrical safety, play an important role in protecting instruments and related electronic equipment from surge voltage and current impacts. Currently, the surge protection modules commonly used in the market are relatively large in size and are usually designed to protect single-phase or three-phase AC power input.

[0003] Digital meters typically use DC power, and surge protection modules for DC power supplies are rare on the market. Whether AC or DC, surge protection modules generally use DIN rail mounting housings, and the input and output of the protection module need to be connected via cables. Current surge protection modules primarily protect only the power line. However, digital meters, in addition to the power interface, also have a communication interface, which also requires appropriate protection. Furthermore, existing surge protection modules are relatively large and have high requirements for the installation environment; typically, the meter is installed inside a cabinet, and the surge protection module is mounted on a DIN rail inside the cabinet. In modern industry, intelligence and integration have become a development trend. Digital meters, which fall within the numerous IoT sensors at the forefront, are designed with integration and miniaturization in mind. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned technical deficiencies and provide a miniature surge protection module based on digital meters, which solves the technical problem that the overall size of the surge protection module in the prior art is large, resulting in a cumbersome installation process and high requirements for the installation environment.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, this utility model provides a miniature surge protection module based on digital meters, comprising:

[0007] The assembly shell is a square shell, and one side of the assembly shell is provided with a connecting end. The outer periphery of the connecting end is threadedly connected to a front connector. The assembly shell has an installation chamber inside, and the inner wall of the installation chamber is provided with a limit ring. The limit ring has an installation notch. The top of the assembly shell is provided with a top protrusion. A circuit board is vertically arranged in the installation notch. The top protrusion is threadedly connected to a tail shell.

[0008] In some embodiments, the connecting end includes a hollow cylinder, which is connected to the interior of the mounting cavity, and the outer periphery of the hollow cylinder is provided with a first threaded groove.

[0009] In some embodiments, the front-end connector is an M20 connector.

[0010] In some embodiments, the mounting notch includes a first notch and a second notch, and the first notch and the second notch are symmetrically provided on the limiting ring, and a mounting area is formed between the first notch and the second notch, and a circuit board is disposed in the mounting area.

[0011] In some embodiments, the top protrusion includes a first annular cylinder and a second annular cylinder, the first annular cylinder being disposed at the upper end of the assembly shell and communicating with the mounting chamber, and the upper end of the first annular cylinder being connected to the second annular cylinder.

[0012] In some embodiments, the cross-sectional area of ​​the first annular cylinder is greater than the cross-sectional area of ​​the second annular cylinder.

[0013] In some embodiments, a second threaded groove is formed on the outer periphery of the second annular cylinder.

[0014] In some embodiments, the tail shell includes a first cylindrical body, a connecting piece, and a second cylindrical body; one end of the first cylindrical body is connected to the connecting piece, the upper end of the connecting piece is connected to the second cylindrical body, the first cylindrical body, the connecting piece, and the second cylindrical body are interconnected, and the first cylindrical body is threadedly connected to the second annular cylinder.

[0015] In some embodiments, the circuit board is provided with a power protection circuit and a communication protection circuit; the power protection circuit includes a gas discharge tube GDT1, a protection circuit self-resetting fuse F1, a power inductor L1 and a transient voltage suppression device TVS1, and the communication protection circuit includes a first-stage gas discharge tube GDT2, a protection circuit self-resetting fuse F3, a protection circuit self-resetting fuse F4 and an ESD protection device.

[0016] Compared with the prior art, the present invention provides a miniature surge protection module based on digital metering. By setting a connection end on the assembly shell, it is easy to connect to an M20 connector. The M20 connector is a conventional standard connector that can be purchased on the market, so it will not be described in detail. After the connection end is threadedly connected to the M20 connector, the circuit board is inserted into the mounting notch of the limiting ring inside the mounting cavity, and the M20 connector terminal is directly connected to the circuit board through the connecting wire harness. A 4P, 3.81mm pitch industrial socket is soldered to the tail of the circuit board. The wiring socket just exceeds the top protruding tail plane, which is convenient for wiring on site. The tail shell only serves as a connector conversion and wiring protection design. By unscrewing this part, the wiring socket on the circuit board can be directly seen. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall unfolded structure of the micro surge protection module based on digital metering provided in this embodiment of the utility model;

[0018] Figure 2 This is a schematic diagram of the internal assembly housing of the micro surge protection module based on digital metering provided in this embodiment of the utility model;

[0019] Figure 3 This is a top view of the assembly housing of the micro surge protection module based on digital metering provided in this embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the power protection circuit of the micro surge protection module based on digital meter provided in this embodiment of the utility model;

[0021] Figure 5 This is a schematic diagram of the communication protection circuit of the micro surge protection module based on digital metering provided in this embodiment of the utility model.

[0022] Explanation of reference numerals in the attached drawings: 1. Assembly shell; 11. Connecting end; 111. Hollow cylinder; 112. First threaded groove; 12. Mounting chamber; 121. Limiting ring; 122. Mounting notch; 1221. First notch; 1222. Second notch; 13. Top protrusion; 131. First annular cylinder; 132. Second annular cylinder; 133. Second threaded groove; 2. Circuit board; 3. Tail shell; 31. First cylinder; 32. Connecting piece; 33. Second cylinder. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0024] To address the technical challenges of existing surge protection modules, which are often large in size, leading to cumbersome installation processes and stringent environmental requirements, this invention provides a miniature surge protection module based on digital meters. This module achieves a miniaturized design of the structure and circuitry, enabling it to be directly integrated into field digital meters while providing enhanced protection. It can be directly screwed onto the external output interface of the digital meter, saving space and facilitating wiring and maintenance.

[0025] It should be noted that the micro surge protection module based on digital metering described in this utility model is used in, but not limited to, the electrical field. For ease of explanation, this utility model only uses the application of the micro surge protection module based on digital metering in the electrical field as an example. The principle of the micro surge protection module based on digital metering applied to other types of equipment is essentially the same as that applied to the electrical field, and will not be described in detail here.

[0026] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a micro surge protection module based on digital metering in one embodiment of the present invention. A micro surge protection module based on digital metering includes an assembly shell 1, which is a square shell. One side of the assembly shell 1 is provided with a connecting end 11, and a front connector is threadedly connected to the outer periphery of the connecting end 11. An installation chamber 12 is provided inside the assembly shell 1. A limit ring 121 is provided on the inner wall of the installation chamber 12. An installation notch 122 is provided on the limit ring 121. A top protrusion 13 is provided on the top of the assembly shell 1. A circuit board 2 is vertically arranged in the installation notch 122. A tail shell 3 is threadedly connected to the top protrusion 13.

[0027] In this embodiment, a connecting end 11 is provided on the assembly shell 1 to facilitate the connection of the M20 connector. The M20 connector is a commercially available standard connector, so it will not be described in detail. After the connecting end 11 is threadedly connected to the M20 connector, the circuit board 2 is inserted into the mounting notch 122 of the limiting ring 121 inside the mounting chamber 12, and the M20 connector terminal is directly connected to the circuit board 2 through the connecting wire harness. A 4P, 3.81mm pitch industrial socket is soldered to the tail of the circuit board 2. The wiring socket just extends beyond the tail plane of the top protrusion 13, which facilitates wiring on site. The tail shell 3 only serves as a connector conversion and wiring protection design. By unscrewing this part, the wiring socket on the circuit board 2 can be directly seen.

[0028] In one embodiment, please refer to Figure 1-3To improve the connection efficiency between the assembly shell 1 and the tail shell 3, the connecting end 11 includes a hollow cylinder 111, which is connected to the interior of the mounting chamber 12. A first threaded groove 112 is provided on the outer periphery of the hollow cylinder 111. The front connector is an M20 connector. The mounting notch 122 includes a first notch 1221 and a second notch 1222. The limiting ring 121 has symmetrically provided first and second notches 1221, forming a mounting area between them. A circuit board 2 is installed within this mounting area. The top protrusion 13 includes a first annular cylinder 131 and a second annular cylinder 1322. 2. The first annular cylinder 131 is disposed on the upper end of the assembly shell 1 and communicates with the installation chamber 12. The upper end of the first annular cylinder 131 is connected to the second annular cylinder 132. The cross-sectional area of ​​the first annular cylinder 131 is larger than the cross-sectional area of ​​the second annular cylinder 132. The outer periphery of the second annular cylinder 132 is provided with a second threaded groove 133. The tail shell 3 includes a first cylinder 31, a connecting piece 32 and a second cylinder 33. One end of the first cylinder 31 is connected to the connecting piece 32. The upper end of the connecting piece 32 is connected to the second cylinder 33. The first cylinder 31, the connecting piece 32 and the second cylinder 33 are interconnected, and the first cylinder 31 is threadedly connected to the second annular cylinder 132.

[0029] In this embodiment, the hollow cylinder 111 is connected to the mounting cavity, and a first threaded groove 112 is provided on the outer periphery of the hollow cylinder 111 to facilitate connection with the front-end M20 connector. A limiting ring 121 is provided in the mounting cavity 12, and a first notch 1221 and a second notch 1222 are respectively opened on the limiting ring 121 to facilitate the circuit board 2 to slide from top to bottom into the mounting cavity 12 and connect the circuit board 2 to the M20 connector. A first annular cylinder 131 and a second annular cylinder 132 are provided on the assembly shell 1, and a second threaded groove 133 is opened on the second annular cylinder 132 to facilitate the threaded connection of the tail shell 3 on the second threaded groove 133. This device minimizes the structure while strengthening protection, and can be directly integrated into the field digital meter. It can be directly screwed onto the external output interface of the digital meter without occupying space, which is convenient for wiring and maintenance. Furthermore, it gets rid of the bulky and cumbersome mode of traditional equipment.

[0030] In one embodiment, please refer to Figure 3 and Figure 4 To facilitate the adaptation of the circuit board 2 to the reduced structure, miniaturization improvements were made to the power protection circuit and the communication protection circuit.

[0031] In this embodiment, the power supply protection circuit employs a three-stage protection design. The first stage uses a gas discharge tube (GDT1) placed near the power inlet. The gas discharge tube has high insulation resistance, strong surge protection capability, and can withstand large inrush currents, making it suitable as a primary protection stage. This stage can discharge large surge impacts to ground. However, the gas discharge tube also suffers from drawbacks such as large discharge delay and low operating voltage accuracy, making it unable to respond to surge impacts in a timely manner and difficult to accurately control the protection threshold. A second-stage protection circuit is added, consisting of a self-resetting fuse (F1) and a power inductor (L1). The self-resetting fuse (F1) provides current limiting protection, while the power inductor (L1) acts as a decoupling delay. When current flows through the inductor, the self-inductance generates a magnetic field around it. This magnetic field prevents further changes in the current, thus generating an electromotive force opposite to the original current. This electromotive force hinders the change in current, thereby stabilizing the current. This delay effect is crucial. On the one hand, it allows large surge impacts to be absorbed as much as possible in the first stage, and on the other hand, it provides a delay for current conduction in the third stage. The third-stage protection circuit consists of a transient voltage suppression device (TVS1). The power handling capability of the TVS tube is not as strong as that of the gas discharge tube in the first stage, but its advantages of fast response speed and low clamping voltage allow it to quickly absorb the residual surge voltage after the first two stages of protection and accurately limit the voltage threshold, thus providing reliable protection for the load circuit. C1 and C2 after the third-stage protection circuit act as filters, and D1 acts as a reverse connection protection device.

[0032] The communication protection circuit consists of two stages. The first stage, a gas discharge tube (GDT2), is connected between lines A and B, with the third pin connected to ground. This provides both common-mode and differential-mode protection for the communication line. This device is used for primary protection, primarily to absorb high-energy surges. Under normal conditions, the GDT is in a high-impedance state. When the surge voltage reaches its trigger voltage, it quickly conducts, discharging the large current to ground. The second stage consists of resettable fuses F3 and F4 and an ESD protection device, TVS3. F3 and F4 provide current-limiting protection for the line, while TVS3 quickly absorbs residual impacts and precisely limits the voltage amplitude.

[0033] To better understand this utility model, the following is combined with... Figures 1 to 5 The technical solution of this utility model is described in detail below: This application makes corresponding improvements to the power protection circuit and communication protection circuit of circuit board 2, wherein:

[0034] The power supply protection circuit employs a three-stage protection design. The first stage uses a gas discharge tube (GDT1) placed near the power input. The GDT1 has high insulation resistance, strong surge protection capability, and can withstand large inrush currents, making it suitable as the first-stage protection. This part can discharge large surge impacts to ground. However, the GDT1 also has drawbacks such as large discharge delay and low operating voltage accuracy, making it unable to respond to surge impacts in a timely manner and difficult to accurately control the protection threshold. A second-stage protection circuit is added, consisting of a resettable fuse (F1) and a power inductor (L1). The resettable fuse (F1) provides current limiting protection, while the power inductor (L1) acts as a decoupling delay. When current flows through the inductor, self-inductance generates a magnetic field around it. It will prevent further changes in current, thereby generating an electromotive force opposite to the original current. This electromotive force will hinder the change in current, thus stabilizing the current. This delay effect is crucial. On the one hand, it allows large surge impacts to be absorbed as much as possible in the first stage, and on the other hand, it can delay the current flow in the third stage. The third-stage protection circuit consists of a transient voltage suppression device (TVS1). The power handling capability of the TVS tube is not as strong as that of the gas discharge tube in the first stage, but its advantages of fast response speed and low clamping voltage allow it to quickly absorb the residual surge voltage after the first two stages of protection and accurately limit the voltage threshold, thus providing reliable protection for the load circuit. C1 and C2 after the third-stage protection circuit play a filtering role, and D1 plays a reverse connection protection role.

[0035] Communication protection circuit; The communication protection circuit consists of two stages of protection circuit. The first stage is a gas discharge tube GDT2 connected between lines A and B, with the third pin connected to ground. It simultaneously provides common-mode and differential-mode protection for the communication line. This device is used for primary protection, mainly to absorb high-energy surges. Under normal conditions, GDT is in a high-impedance state. When the surge voltage reaches its trigger voltage, it quickly conducts, discharging the large current to ground. The second stage consists of resettable fuses F3 and F4 and an ESD protection device TVS3. F3 and F4 are used for current-limiting protection of the line, while TVS3 is used to quickly absorb residual impacts and precisely limit the voltage amplitude.

[0036] The structural improvement in this application is that the assembly shell 1 is set as a square shell, and an installation chamber 12 is provided inside the assembly shell 1. A hollow cylinder 111 communicating with the installation chamber 12 is provided on the assembly shell 1, and a first threaded groove 112 is provided on the outer periphery of the hollow cylinder 111 to facilitate the installation of the M20 connector on the first threaded groove 112. By providing a limiting ring 121 in the installation chamber 12, and respectively opening a first notch 1221 and a second notch 1222 on the limiting ring 121, it is convenient to slide the circuit board 2 from top to bottom into the installation chamber 12 and connect the circuit board 2 with the M20 connector. Furthermore, a first annular cylinder 131 and a second annular cylinder 132 are provided on the assembly shell 1, and the second annular cylinder 132... A second threaded groove 133 is provided on the upper part to facilitate the threaded connection of the tail shell 3 on the second threaded groove 133. Under the premise of strengthening protection, the structure is minimized and can be directly integrated into the field digital meter. It can be directly screwed onto the external output interface of the digital meter without occupying space, which facilitates wiring and maintenance and greatly improves the installation and subsequent maintenance efficiency of the staff. This device enables the surge protection of digital meters to get rid of the traditional bulky and cumbersome mode, and can be integrated into the digital meter in a refined way. It also strengthens the protection of both the power supply and communication circuit. Actual testing has verified that it can easily pass the surge immunity level 4 and electrical fast transient / burst level 4 test standards.

[0037] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A miniature surge protection module based on digital meters, characterized in that, include: The assembly housing is a square shell with a connecting end on one side. A front connector is threaded onto the outer periphery of the connecting end. An installation chamber is provided inside the assembly housing, and a limit ring is provided on the inner wall of the installation chamber. An installation notch is provided on the limit ring. A top protrusion is provided on the top of the assembly housing. A circuit board is vertically arranged in the installation notch. A tail shell is threaded onto the top protrusion. The front connector is an M20 connector. The M20 connector terminal is directly connected to the circuit board through a connecting wire harness. A wiring socket is welded to the tail of the circuit board, and the wiring socket extends just beyond the tail plane of the top protrusion.

2. The miniature surge protection module based on digital metering according to claim 1, characterized in that: The connecting end includes a hollow cylinder, which is connected to the interior of the mounting cavity, and the outer periphery of the hollow cylinder is provided with a first threaded groove.

3. The miniature surge protection module based on digital metering according to claim 1, characterized in that: The mounting notch includes a first notch and a second notch. The first notch and the second notch are symmetrically provided on the limiting ring. An mounting area is formed between the first notch and the second notch. A circuit board is provided in the mounting area.

4. A miniature surge protection module based on digital metering according to claim 1, characterized in that: The top protrusion includes a first annular cylinder and a second annular cylinder. The first annular cylinder is disposed on the upper end of the assembly shell and communicates with the mounting chamber. The upper end of the first annular cylinder is connected to the second annular cylinder.

5. A miniature surge protection module based on digital metering according to claim 4, characterized in that: The cross-sectional area of ​​the first annular cylinder is greater than that of the second annular cylinder.

6. A miniature surge protection module based on digital metering according to claim 5, characterized in that: The second annular cylinder has a second threaded groove on its outer circumference.

7. A miniature surge protection module based on digital metering according to claim 6, characterized in that: The tail shell includes a first cylindrical body, a connecting piece, and a second cylindrical body; one end of the first cylindrical body is connected to the connecting piece, the upper end of the connecting piece is connected to the second cylindrical body, the first cylindrical body, the connecting piece, and the second cylindrical body are interconnected, and the first cylindrical body is threadedly connected to the second annular cylinder.

8. A miniature surge protection module based on digital metering according to claim 1, characterized in that: The circuit board is equipped with a power protection circuit and a communication protection circuit. The power protection circuit includes a gas discharge tube GDT1, a self-resetting fuse F1, a power inductor L1, and a transient voltage suppression device TVS1. The communication protection circuit includes a first-stage gas discharge tube GDT2, a first fuse F3, a second fuse F4, and an ESD protection device.

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