A high-grade lightning protection device for electronic equipment

Abstract

The utility model discloses a high -grade thunder and lightning protection device for electronic equipment. Including connector structure unit, voltage embedding position unit, current discharge unit, connector structure unit and current discharge unit integration design, the connector structure unit includes the connector, and the connector is welded on the current discharge unit through the connector pad, the current discharge unit adopts the PCB board of independent design, and this PCB board adopts the structure of three -layer board, and the copper ground layer on the PCB board is single layer, and the voltage clamping unit is welded on the PCB board, and the input voltage negative line is directly connected with the copper ground layer on the PCB board, voltage clamping unit is by single two -way TVS pipe composition. Solve the problem that the lightning surge of power supply system and precision electronic instrument is difficult to protect, and the volume is big, and the lightning protection level is low, realize the high -grade thunder and lightning protection of low cost, small size, high performance.

Description

Technical Field

[0001] This utility model belongs to the field of electronic information technology, specifically relating to a high-level lightning protection device for electronic equipment. Background Technology

[0002] Because lightning has a very high instantaneous energy, conventional capacitor filtering methods are not effective in absorbing it. Discharge-type devices are required. Lightning protection connectors incorporate surge protection devices such as TVS diodes, varistors, and gas discharge tubes within the components or connectors. When lightning induces an overvoltage on the contacts, the contacts are protected by TVS breakdown, discharging the surge current to the housing (ground) and limiting the output voltage amplitude to ensure the safety of the protected circuit. The connector housing is tightly connected to the equipment chassis with conductive rubber pads to achieve good grounding.

[0003] Lightning protection devices can be divided into two categories based on their characteristics: switching type and voltage limiting type. The main difference is that voltage limiting type devices have a clamping function, while switching type devices do not. For example... Figure 2 As shown. From a working principle perspective, TVS diodes are based on the PN junction avalanche effect, while MOV varistors are based on the potential barrier effect between zinc oxide grains. Once a pulse is received, the impedance between the two electrodes instantaneously changes from high to low, clamping the pulse voltage to a certain value. GDT ceramic gas discharge tubes and SPG glass gas discharge tubes operate on the principle of gas breakdown discharge. When the electric field strength between the two electrodes exceeds the gas breakdown strength, a gap discharge is caused, thereby limiting the voltage between the two electrodes and protecting other devices connected in parallel with the gas discharge tube.

[0004] TVS diodes offer precise clamping and short response times, but have relatively low discharge power, making them suitable for lightning protection in signal circuits. MOV varistors have slower response times, higher leakage current, and faster aging, but higher current carrying capacity, making them suitable for power supply ports. GDT ceramic gas discharge tubes and SPG glass gas discharge tubes have the advantages of low junction capacitance and high discharge power, but they have accompanying current and lack clamping functionality. They are typically used in conjunction with voltage-limiting devices, resettable fuses, and current-limiting resistors, and can be applied to high-speed signal transmission ports.

[0005] The above-mentioned devices have obvious advantages and disadvantages. When necessary, multiple devices can be used in combination to achieve the best lightning protection performance. The selection of lightning protection devices should follow the design principles below:

[0006] ① The maximum reverse working voltage of the surge protection device shall not be lower than the maximum working voltage of the line.

[0007] ② The maximum pulse power of the lightning protection device is greater than the maximum instantaneous power of lightning in the circuit.

[0008] ③ The clamping voltage after the surge protection device activates is lower than the safe voltage of the protected equipment.

[0009] ④ The parasitic capacitance of the lightning protection circuit does not affect high-speed signal transmission.

[0010] Existing technological shortcomings:

[0011] B5 level lightning protection often uses SPD modules (such as CN115954844A), but these have the problem of large size (≥50mm3) and inability to be adapted to miniaturized devices.

[0012] Traditional three-level protection architecture (such as CN217590256U) relies on a gas discharge tube (GDT) connected in series with a unidirectional TVS, which has a response timing misalignment problem, resulting in excessively high residual voltage (typical value ≥1200V) and an increase in cost of more than 30%.

[0013] Two-way surge protection requires parallel TVS diodes (such as CN106972014A). These TVS diodes are unidirectional and distributed, resulting in a large PCB area and high residual voltage (≥1200V). Utility Model Content

[0014] This utility model discloses a high-level lightning protection device for electronic equipment, which solves the problems of difficult protection against lightning surges in power systems and precision electronic instruments, large size, and low lightning protection level, and achieves high-level lightning protection with low cost, small size, and high performance.

[0015] The above objectives are achieved through the following technical solutions:

[0016] A high-level lightning protection device for electronic equipment includes a connector structure unit, a voltage clamping unit, and a current discharge unit. The connector structure unit and the current discharge unit are integrated into a single design. The connector structure unit includes a connector, which is soldered to the current discharge unit via connector pads. The current discharge unit uses an independently designed PCB board with a three-layer structure. The copper ground layer on the PCB board is a separate layer. The voltage clamping unit is soldered to the PCB board, and the negative input voltage line is directly connected to the copper ground layer on the PCB board. The voltage clamping unit is composed of a single bidirectional TVS diode.

[0017] Furthermore, the connector structure unit also includes a metal shell, on which screw holes are provided for fixing the metal shell to the housing of the protected device. The metal shell is connected to the copper ground plane of the PCB intermediate layer through four studs, the bottom of which has threaded holes, via through holes on the current discharge unit, and is fastened with screws.

[0018] Furthermore, the PCB board adopts a three-layer structure, specifically including a top PCB layer, a middle PCB layer, and a bottom PCB layer. There is a via on each of the four sides of the PCB board, which can be tightly connected to the studs on the connector structural unit by screws. The copper ground layer on the PCB board is located in the middle PCB layer and is a separate layer. The voltage clamping unit is soldered on the PCB board, and one end is connected to the positive input pin of the connector pad through the positive voltage network copper foil. The negative input voltage line is directly connected to the copper ground layer.

[0019] Furthermore, the TVS diode is selected as SY6KA042C, with a maximum clamping voltage of 77V. It adopts a pin-type package and contacts the copper ground plane of the PCB middle layer of the current discharge unit.

[0020] Compared with the prior art, the significant advantages of this utility model are:

[0021] 1. This utility model achieves a balance between cost and performance: it adopts a bidirectional TVS diode with a clamping voltage rating of 77V, which is connected in parallel between the positive input voltage line and ground. The negative input voltage line is directly connected to the chassis ground through the PCB and the integrated structure. Only one bidirectional TVS is needed to achieve surge protection design for the input line, which greatly reduces the cost while taking into account the surge protection performance.

[0022] 2. Low impedance grounding of this utility model: Through the integrated structure of a centralized grounding layer of a three-layer PCB, studs and connectors are combined. First, the connector is directly soldered to the independently designed PCB. The ground layer is a separate layer of the PCB. The ground layer is connected to the metal shell where the connector is located by four studs. Finally, the metal shell is installed on the equipment housing by screws, thereby achieving low impedance grounding, which can reduce the impedance to ground from 0.5Ω in the traditional solution to ≤0.05Ω.

[0023] 3. This utility model has good protective performance: the highest level of lightning protection is B5 level. The test waveforms under this level are divided into two groups. The first group has an input voltage of 3200V and an input current of 128A; the second group has an input voltage of 1600V and an input current of 1600A. Under these two sets of tests, the voltage can be clamped to about 60V, and the current is basically discharged, thus achieving B5 level lightning protection.

[0024] 4. This utility model has a small size: The size advantage is achieved through the combined effect of multiple units. The voltage clamping unit uses only a single bidirectional TVS diode, reducing its size. The voltage clamping unit is soldered onto the current discharge unit, and the integrated connector design further reduces the size by soldering the connector onto the current discharge unit. The final overall size, including the connector, is only 54×38×53.8mm. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the connection structure of the various components of this utility model;

[0027] Figure 3 Design a circuit diagram for the voltage clamping unit;

[0028] Figure 4 Waveform diagrams for B5 level lightning test: a) Voltage / current curve of waveform 3; b) Voltage / current curve of waveform 5a.

[0029] The attached diagram is labeled as follows: 1. Voltage clamping unit; 2. Connector structure unit; 3. Current discharge unit; 3-1. PCB top layer; 3-2. PCB middle layer; 3-3. PCB bottom layer; 3-4. Via; 4. Positive voltage network copper foil; 2-1. Connector pad; 2-2. Connector; 2-3. Metal shell; 2-4. Stud; 2-5. Screw hole. Detailed Implementation

[0030] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0031] like Figure 1 , Figure 2 As shown, this embodiment provides a high-level lightning protection device for electronic equipment, including a connector structure unit 2, a voltage clamping unit 1, and a current discharge unit 3; Figure 3The diagram shows the design circuit of voltage clamping unit 1. Voltage clamping unit 1 consists of a single bidirectional TVS diode. A bidirectional TVS diode with a suitable clamping voltage is selected based on the voltage withstand level of the protected circuit. The TVS diode selected is "SY6KA042C," with a maximum clamping voltage of 77V. A through-hole package is used to allow connection to the current discharge unit. The through-hole package allows direct contact with the copper ground plane of the PCB middle layer of the current discharge unit, eliminating the need for a via to the middle layer copper ground plane. This reduces contact impedance and the risk of creepage caused by connecting to the top layer copper ground plane. One pin of the voltage clamping unit is connected to one side of the positive voltage network copper of the connector pad input terminal on the PCB middle layer, and the other side is connected to the outer copper ground plane of the PCB middle layer. When a lightning voltage waveform enters from the input terminal, the bidirectional TVS diode activates, clamping the large voltage from the lightning test to its own clamping voltage, thus protecting the safety of downstream equipment. Similarly, due to the design of the bidirectional TVS diode, it can also clamp the lightning voltage on the ground-to-input power line to a safe voltage. This design can provide bidirectional lightning protection with only a single bidirectional TVS diode. The packaged design allows direct contact with the copper ground plane of the PCB intermediate layer, reducing contact impedance and improving the protection capability against lightning voltage and current. Furthermore, the design of a single bidirectional TVS diode significantly reduces the size and cost of lightning protection devices.

[0032] This design has the following three advantages:

[0033] 1. A single bidirectional TVS diode is used to achieve bidirectional lightning voltage clamping and protection between the input and ground, and between the input and ground.

[0034] 2: The design of a single bidirectional TVS diode reduces the size and cost of lightning protection devices;

[0035] 3: The bidirectional TVS diode adopts a pin-type package, which can form a low-impedance connection with the ground, thereby improving the lightning current discharge capability.

[0036] Current discharge unit:

[0037] The current discharge unit uses an independently designed PCB board with a three-layer structure: PCB top layer 3-1, PCB middle layer 3-2, and PCB bottom layer 3-3. Each side of the PCB board has a via 3-4, which can be tightly connected to the studs on the connector structural unit using screws. The ground plane on the PCB board is located on the middle layer and is a separate layer. The voltage clamping unit is soldered onto the PCB board, with one end connected to the positive input pin of the connector pad 7 via a positive voltage network copper foil 6. The negative input voltage line is directly connected to the copper ground plane. Lightning on the positive line can quickly discharge the discharge current through the bidirectional clamping TVS diode to the nearest copper ground plane. The independent copper ground plane provides a good current discharge path for the lightning current. After flowing through the copper ground plane, the current is conducted through the surrounding vias to the studs of the structural unit, and then through the studs to the metal shell, thus reaching the ground. Lightning on the negative line directly enters the copper ground plane and is guided to the ground through the same path as the positive line. This design enhances the discharge capacity of lightning current, thereby improving lightning protection capabilities. The key features and protection points of this unit lie in its use of a separately designed PCB, integrating the voltage clamping unit and current discharge unit into one, and its unique connection method with the structural unit, thus achieving a high level of lightning protection.

[0038] This design has the following six advantages:

[0039] 1: The first layer is the top layer of the PCB, and the third layer is the bottom layer of the PCB. This increases the distance between the copper ground layer and the casing ground, eliminating the possibility of creepage during lightning tests.

[0040] 2: The connector can be directly soldered onto the PCB board to form an integral structure, which greatly reduces the size;

[0041] 3: Lightning current enters the voltage clamping unit through the connector and then enters the current discharge unit. Since the connector, voltage clamping unit and current discharge unit are all concentrated on the PCB board, a low impedance path is provided for current discharge.

[0042] 4: The copper ground layer is an independent layer on the PCB board, providing a large-area ground loop for current discharge.

[0043] 5: The current discharge unit can be tightly connected to the structural unit through the through hole, and can discharge the lightning current to the ground in a low impedance form.

[0044] 6: The negative input voltage line is directly connected to the copper ground layer, which reduces the protection of the negative input voltage to ground, reduces the size, and lowers the cost.

[0045] Connector structural unit:

[0046] Connector structural units such as Figure 1 , Figure 2As shown, the structural unit consists of the following parts: screw holes 11, studs 10, a metal shell 9, a connector 8, and connector pads 7. Screw holes are formed in the metal shell to allow it to be fixed to the housing of the protected equipment, integrating the metal shell of the connector structural unit with the housing of the protected equipment. This increases the contact area with the ground plane, resulting in low ground impedance and a better discharge path for lightning current. The stud connects the metal shell to the current discharge unit. The stud and metal shell are integral, milled by a milling machine, and have threaded holes at the bottom. These holes connect to the copper ground plane of the PCB intermediate layer via vias on the current discharge unit and are secured with screws. This component serves two purposes: first, it connects the current discharge unit and the structural unit at the four corners, enhancing the structural strength of the entire lightning protection device; second, it acts as a bridge between the copper ground plane and the metal shell, allowing lightning current to transfer from the copper ground plane to the metal shell and reach the housing of the protected equipment, ultimately flowing to the ground.

[0047] This design has the following three advantages:

[0048] 1; The screw hole design tightly connects the metal shell on the structural unit to the outer shell of the protected device, providing a discharge channel for lightning current;

[0049] 2: The metal shell fits snugly against the shell of the device to be protected, thus achieving a low-impedance connection with the equipment shell and improving the discharge capacity;

[0050] 3: The four studs and the metal shell are integrated as a whole and interconnected with the current discharge unit. This ensures the structural strength of the lightning protection device while guiding the lightning discharge current on the current discharge unit to the metal shell of the structural unit.

[0051] Figure 4 Waveform diagram of a B5 level lightning test: Figure 4 In the diagram, a) is the voltage / current curve of waveform 3; b) is the voltage / current curve of waveform 5a.

Claims

1. A high-level lightning protection device for electronic equipment, characterized in that, The device includes a connector structure unit, a voltage clamping unit, and a current discharge unit. The connector structure unit and the current discharge unit are designed as an integrated unit. The connector structure unit includes a connector, which is soldered to the current discharge unit via connector pads. The current discharge unit uses an independently designed PCB board with a three-layer structure. The copper ground layer on the PCB board is a separate layer. The voltage clamping unit is soldered to the PCB board, and the negative input voltage line is directly connected to the copper ground layer on the PCB board. The voltage clamping unit is composed of a single bidirectional TVS diode.

2. The high-level lightning protection device for electronic equipment according to claim 1, characterized in that, The connector structure unit also includes a metal shell with screw holes for fixing the metal shell to the housing of the protected device. The metal shell is connected to the copper ground plane of the PCB intermediate layer through four studs with threaded holes at the bottom, which are connected to the current discharge unit through vias and secured with screws.

3. A high-level lightning protection device for electronic equipment according to claim 1 or 2, characterized in that, The PCB board adopts a three-layer structure, specifically including a top PCB layer, a middle PCB layer, and a bottom PCB layer. There is a via on each of the four sides of the PCB board, which can be tightly connected to the studs on the connector structural unit by screws. The copper ground layer on the PCB board is located in the middle PCB layer and is a separate layer. The voltage clamping unit is soldered on the PCB board, and one end is connected to the positive input pin of the connector pad through the positive voltage network copper foil. The negative input voltage line is directly connected to the copper ground layer.

4. A high-level lightning protection device for electronic equipment according to claim 3, characterized in that, The TVS diode selected is SY6KA042C, with a maximum clamping voltage of 77V. It adopts a pin-type package and contacts the copper ground plane of the PCB middle layer of the current discharge unit.

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