Multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility detection

Abstract

The utility model relates to a multifunctional transient pulse suppression device for electromagnetic compatibility detection. Comprising a shielding packaging shell, an A-port patch cord, an A-port signal transmission port, an A-port transient pulse amplitude limiting unit, an A-port transient pulse isolation unit, an A-port transient pulse suppression unit, an A-port filtering decoupling unit, a B-port filtering decoupling unit, a B-port transient pulse suppression unit, a B-port transient pulse isolation unit and a B-port transient pulse amplitude limiting unit. The B port signal transmission port, the B port patch cord and the shielding packaging shell grounding port are connected to the shielding packaging shell. According to the utility model, various transient pulses input to the input end and the output end can be suppressed at the same time, continuous communication is maintained in various transient pulse interference tests, and the transient electromagnetic pulse interference resistance performance of a tested sample and auxiliary equipment can be effectively distinguished.

Description

Technical Field

[0001] The utility model relates to a multifunctional transient pulse suppression device for electromagnetic compatibility detection, belonging to the technical field of electromagnetic compatibility testing. Background Art

[0002] The purpose of electromagnetic compatibility test is to examine whether the system and equipment can work normally and not interfere with each other in a specific electromagnetic environment. Transient electromagnetic interference pulse test is an important part of electromagnetic compatibility test, which mainly considers whether the equipment can meet the expected performance requirements and safety requirements under the external transient electromagnetic pulse interference conditions. A large number of transient pulse test waveforms with different characteristics are specified in the standard system in the field of electromagnetic compatibility. For example, ISO 7637 (GB / T 21437) and ISO10605 (GB / T 19951) standards specify transient electromagnetic pulses suitable for the evaluation of the anti-electromagnetic interference performance of vehicles and vehicle-mounted components; IEC 61000 (GB / T 17626) series standards specify transient electromagnetic pulses for the evaluation of the anti-electromagnetic interference performance of civil and industrial products; GJB 151B, GJB152B, MIL-STD-461F specify transient electromagnetic pulses for the evaluation of the anti-electromagnetic interference performance of military products; DO-160 specifies transient electromagnetic pulses for the evaluation of the anti-electromagnetic interference performance of airborne equipment, etc.

[0003] In recent years, the functional integration and intelligent networking of products such as transportation vehicles and medical devices have increased rapidly, and their electromagnetic compatibility safety has attracted widespread attention, and the requirements for the anti-electromagnetic interference performance of products have become increasingly stringent. The performance of products against transient electromagnetic pulse interference is an important part of the evaluation of anti-electromagnetic interference performance. Transient electromagnetic pulse interference generally has the characteristics of high amplitude and short rise time, which can be coupled to the test sample or auxiliary equipment circuit. The coupling forms include direct conduction coupling and indirect field-induced coupling, which can easily lead to unexpected performance degradation or failure of the product.

[0004] According to the requirements of the quality management system, the test samples need to be connected to auxiliary equipment in the electromagnetic compatibility test to improve the relevant functional configuration so that the test samples are in a typical working state. The test samples need to meet the harsh electromagnetic environment due to the work tasks, and the anti-electromagnetic interference performance of some auxiliary equipment may not meet the actual requirements, such as workstations. At this time, unexpected performance degradation or failure may occur in the highly integrated system. This phenomenon of "unexpected performance degradation or failure" has brought great trouble to the accurate determination of the anti-electromagnetic interference performance of the test samples, such as multi-functional intelligent network terminals, vehicle-mounted integrated entertainment systems, camera integration units, vehicle-mounted electronic controllers, etc. The current transient electromagnetic pulse protection measures are mainly aimed at preventing direct damage to the test samples. The pulse suppression process may cause product function failure or performance degradation, and even sacrifice part of the product performance for protection. When faced with higher requirements for electromagnetic compatibility safety (for example, when requiring the timeliness and quality of data communication), it is necessary to provide effective protection for auxiliary equipment to achieve accurate determination of the anti-static interference performance of the test samples. It can be seen that in transient pulse interference tests, it is extremely important to introduce a pulse suppression device to achieve "discrimination" of the performance of the test sample and auxiliary equipment. Utility Model Content

[0005] The purpose of the utility model is to provide a multifunctional transient pulse suppression device to achieve continuous Ethernet communication during transient pulse suppression, to solve the performance degradation problem of Ethernet connection interruption during pulse suppression of traditional equipment, and to increase the electrostatic discharge pulse suppression capability to 30kV while maintaining continuous system communication, while expanding the application for a variety of transient electromagnetic pulses.

[0006] In order to achieve the above-mentioned purpose, the technical solution of the utility model is to provide a multifunctional transient pulse suppression device for electromagnetic compatibility detection, characterized in that it includes: a shielded packaging shell, an A-port adapter, an A-port signal transmission port, an A-port transient pulse limiting unit, an A-port transient pulse isolation unit, an A-port transient pulse suppression unit, an A-port filtering and decoupling unit, a B-port filtering and decoupling unit, a B-port transient pulse suppression unit, a B-port transient pulse isolation unit, a B-port transient pulse limiting unit, a B-port signal transmission port, a B-port adapter, and a shielded packaging shell grounding port connected to the shielded packaging shell;

[0007] The A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit and the A-port filtering and decoupling unit are connected in sequence, the A-port transient pulse limiting unit is connected to the A-port signal transmission port, and the A-port signal transmission port is connected to the A-port adapter cable; the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are connected in sequence, the B-port filtering and decoupling unit is connected to the A-port filtering and decoupling unit, the B-port transient pulse limiting unit is connected to the B-port signal transmission port, and the B-port signal transmission port is connected to the B-port adapter cable;

[0008] The A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are integrated into a circuit board, and the circuit board is encapsulated in a shielding packaging shell, and the shielding packaging shell is provided with an A-port signal transmission port and a B-port signal transmission port;

[0009] Or the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are located on respective independent circuit boards, each group of circuit boards is encapsulated in a shielded packaging shell, and functionally adjacent packaging shells are connected by shielded wiring harnesses, wherein the shielded packaging shell encapsulating the A-port transient pulse limiting unit is provided with an A-port signal transmission port, and the shielded packaging shell encapsulating the B-port transient pulse limiting unit is provided with a B-port signal transmission port.

[0010] Or at least two of the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are freely combined and packaged in a common shielding packaging shell in a combined form, wherein the shielding packaging shell encapsulating the A-port transient pulse limiting unit is provided with an A-port signal transmission port, and the shielding packaging shell encapsulating the B-port transient pulse limiting unit is provided with a B-port signal transmission port.

[0011] Preferably, the shielding packaging shell is a three-dimensional fully enclosed metal shell.

[0012] Preferably, the A-port adapter, the A-port signal transmission port, the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit and the A-port filtering and decoupling unit are symmetrical at left and right ends with the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit, the B-port transient pulse limiting unit, the B-port signal transmission port and the B-port adapter.

[0013] Preferably, the A-port adapter wire is close to the A-port signal transmission port and the B-port adapter wire is close to the B-port signal transmission port, allowing the nearest harness position to be installed to increase the magnetic beads that match the transmission signal impedance.

[0014] Preferably, the A-port signal transmission port and the B-port signal transmission port adopt multi-core FGG / EGG sockets that meet the requirements of multi-line switching.

[0015] Preferably, the grounding point of the shielding package shell adopts a copper tinned braided tape with a width greater than 5 mm, and the grounding impedance is less than 0.5 mΩ.

[0016] Preferably, the impedance of the ground connection line between the circuit board and the shielding packaging shell is less than 0.1 mΩ, the line diameter is greater than 2 mm, and the length is less than 10 mm.

[0017] The utility model can simultaneously suppress multiple transient pulses input to the input end (end A) and the output end (end B), maintain continuous communication during multiple transient pulse interference tests, and effectively "distinguish" the transient electromagnetic pulse interference performance of the tested samples and auxiliary equipment.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. At a certain test level, the Ethernet communication connection is maintained uninterrupted during the transient electromagnetic interference pulse suppression process.

[0020] 2. At a certain test level, the transient pulse interference resistance performance of a single unit in the system can be "identified".

[0021] 3. The transient pulse passes through the transient pulse isolation unit, the limiting unit and the transient pulse isolation unit first, reducing the transient change of the transient pulse interference current caused by the rapid release of the transient pulse at the protection end, thereby reducing the coupling energy to the device circuit during the pulse suppression process.

[0022] 4. For the transient pulse test levels described in 1 and 2, the following capabilities can be achieved (both meet the maximum transient pulse voltage defined in the relevant standards and the maximum pulse voltage that can be generated by mainstream testing instruments):

[0023] 5. For 1, 2 and 4, the transient fast pulse (3a / 3b) test voltage defined in ISO 7637-3:2016 (GB / T 21437.3-2012) reaches ±1kV (the standard does not require a higher test level, and there is no widely used pulse generator that produces a higher test voltage);

[0024] 6. For 1, 2 and 4, the electrostatic discharge pulse voltage (multiple impedance conditions) defined in ISO 10605:2023 and GB / T19951-2019 can reach ±30kV;

[0025] 7. For IEC 61000-4-4:2012 (GB / T 17626.4-2018) electrical fast transient pulse group (5kHz and 100kHz), it reaches ±4kV.

[0026] 8. When the device of the utility model is inserted into 10Mbps and 100Mbps Ethernet links, the communication delay increment caused is no more than 2μs.

[0027] 9. The device of the utility model is inserted into 10Mbps and 100Mbps Ethernet links, and the communication packet loss rate caused during the 10Mbps / 100Mbps Ethernet communication process is less than 0.1%.

[0028] 10. Transient electromagnetic pulse suppression can be performed at both the input end (end A) and the output end (end B).

[0029] 11. The input end (A end) and the output end (B end) are symmetrical and can be used interchangeably.

[0030] 12. Through the wiring harness conversion method, it can be applied to various ports, etc.

[0031] 13. The device’s own shielding effectiveness against external electromagnetic fields reaches more than 55dB.

[0032] 14. The transfer impedance of the device joint (an indicator that affects the shielding effectiveness through the joint connection) is less than 1mΩ.

[0033] 15. The impedance of the grounding wire of the device casing is less than 0.5mΩ.

[0034] 16. The insulation impedance of the device surface (except the grounding installation position and the shielding interface position) is greater than 2MΩ, which can effectively prevent the external transient pulse interference from contacting the device surface and causing indirect coupling to the inside of the device, and also reduce the internal circuit discharge breakdown and conduction through the air to the shielding shell.

[0035] 17. For electrostatic discharge pulses defined in ISO 10605:2023 and GB / T19951-2019,

[0036] 1) The maximum peak absolute value of the residual voltage suppression for ±1kV electrostatic pulse is 11.2V;

[0037] 2) The maximum peak absolute value of the residual voltage suppression for ±2kV electrostatic pulse is 28.5V;

[0038] 3) The maximum peak absolute value of the residual voltage suppression for ±6kV electrostatic pulse is 56.9V;

[0039] 4) The maximum peak absolute value of the residual voltage after ±10kV electrostatic pulse suppression is 78.3V;

[0040] 5) The maximum peak absolute value of the residual voltage after ±15kV electrostatic pulse suppression is 114.6V;

[0041] 6) The maximum peak absolute value of the residual voltage after ±20kV electrostatic pulse suppression is 284.6V;

[0042] 7) The maximum peak absolute value of the residual voltage after ±30kV electrostatic pulse suppression is 359.7V.

[0043] 18. For the fast electrical pulse 3a / 3b defined in ISO 7637-3:2016 (GB / T 21437.3-2021), the pulse suppression residual voltage at voltages of ±1kV and below is not greater than 11.4V. It has good suppression performance for transient slow electrical pulses defined in ISO 7637-3:2016 (GB / T21437.3-2021).

[0044] 19. For the electrical fast pulse group defined in IEC 61000-4-4:2012 (GB / T 17626.4-2018), the pulse suppression residual voltage at ±4kV and below is less than 50V. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a structural schematic diagram of a multifunctional transient pulse suppression device for electromagnetic compatibility testing disclosed by the utility model;

[0046] Figure 2 This is the device structure diagram of this implementation case;

[0047] Figure 3 is a schematic diagram of a multifunctional transient pulse suppression circuit of Example 1;

[0048] Figure 4 This is a schematic diagram of the pulse suppression device function check;

[0049] Figure 5 This is a schematic diagram of electrostatic discharge pulse residual voltage suppression;

[0050] Figure 6 It shows the residual voltage waveform of electrostatic discharge pulse residual voltage suppression;

[0051] Figure 7 It is a schematic diagram of transient fast pulse suppression;

[0052] Figure 8 This is the ISO 7637-3:2016 (GB / T 21437.3-2021) transient fast pulse suppression waveform;

[0053] Fig. 9 The 10Mbps / 100Mbps Ethernet port communication performance verification scheme is illustrated. DETAILED DESCRIPTION

[0054] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0055] like Figure 1 As shown, a multifunctional transient pulse suppression device for electromagnetic compatibility testing disclosed by the utility model has a bilaterally symmetrical structure, including a shielded packaging shell 1, an A-port adapter 2, an A-port signal transmission port 3, an A-port transient pulse limiting unit 4, an A-port transient pulse isolation unit 5, an A-port transient pulse suppression unit 6, an A-port filtering and decoupling unit 7, a B-port filtering and decoupling unit 8, a B-port transient pulse suppression unit 9, a B-port transient pulse isolation unit 10, a B-port transient pulse limiting unit 11, a B-port signal transmission port 12, a B-port adapter 13, and a shielded packaging shell grounding port 14.

[0056] The shielding package shell 1 is a three-dimensional fully enclosed metal shell, including a shell, a top cover and fixing screws, etc. The two ends are respectively connected to the A-port signal transmission port 3 and the B-port signal transmission port 12, and the grounding port of the shielding package shell 1 is connected to the shielding package shell grounding port 14. A preferred embodiment is that the shielding package shell 1 is made of steel conductive material. A preferred embodiment is that the material thickness of the shielding package shell 1 at the lowest frequency of use is greater than 6.5 times the skin depth to achieve a shielding effectiveness greater than 55dB. A preferred embodiment is that each conductive connection section and port connection impedance is less than 0.5mΩ. A preferred embodiment is that the non-overlapping parts of the outer surface and inner surface of the shielding package shell 1 are insulated, and the preferred insulation impedance is greater than 2MΩ to avoid direct coupling of transient pulses conducted by external factors and direct breakdown of high-level transient pulses in the internal circuit to discharge to the shell through the air. A preferred embodiment is that the connection interface of the shielding package shell 1 is coated with a metal coating with high conductivity, excellent ductility and excellent oxidation resistance. A preferred embodiment is that the shielding package shell 1 is treated with (2-5)% lead-tin plating with a thickness of μm level. Reflow tin plating is required to eliminate stress and reduce whisker growth on the tin surface. A preferred embodiment is that metal braided sealing spring pads are installed at the connection of the shielding package shell 1. A preferred embodiment is that the distance between the shielding package shell 1 and the internal circuit board is designed to be greater than 1mm / kV. The distance between the shielding package shell 1 and the internal circuit board can also be adjusted according to the risk of pulse breakdown of the air under different temperature, humidity, air pressure and other conditions and the safe distance for preventing arcs. In addition, when used in insulating liquid media, the distance between the shielding package shell 1 and the internal circuit board can be adjusted. A preferred embodiment is that the distance between the fastening screws of the connection interface of the shielding package shell 1 is not more than 3cm.

[0057] Multiple shielding packaging shells can also be used to respectively encapsulate the A-port transient pulse limiting unit 4, the A-port transient pulse isolation unit 5, the A-port transient pulse suppression unit 6, the A-port filtering and decoupling unit 7, the B-port filtering and decoupling unit 8, the B-port transient pulse suppression unit 9, the B-port transient pulse isolation unit 10, the B-port transient pulse limiting unit 11 and other units.

[0058] Figure 2 The device structure diagram of this embodiment includes a shielding package shell 1, a printed circuit board, a connection port and a wiring harness. The joint between the top cover of the shielding package shell 1 and the shell is embedded. Figure 2 In the figure, E is the joint of the shielding package cover and F is the fastening screw.

[0059] The A-port adapter cable 2 and the B-port adapter cable 13 are adapter cables for application ports and signal transmission ports, and the application ports can be Ethernet ports, USB ports, RS232 ports, CAN protocol ports, etc. The A-port adapter cable 2 and the B-port adapter cable 13 mainly realize the wiring harness switching of different protocol ports, and the line type can be adjusted according to different communication protocols. The A-port adapter cable 2 connects the A-port signal transmission port 3, and the B-port adapter cable 13 connects the B-port signal transmission port 12. A preferred implementation is to use different protocol ports to switch FGG / EGG ports. A preferred implementation is that the A-port adapter cable 2 and the B-port adapter cable 13 use shielded wires to reduce external field coupling, and the shielding effectiveness is greater than 20dB. A preferred implementation is that the thickness of the external insulation layer of the A-port adapter cable 2 and the B-port adapter cable 13 is greater than 0.2mm, and the insulation impedance is greater than 2MΩ to prevent direct breakdown of external transient electromagnetic pulses. A preferred implementation is that the impedance of the wiring harness of the A-port adapter cable 2 and the B-port adapter cable 13 should match the impedance of the transmission signal. A preferred implementation is to add a magnetic bead matching the transmission signal impedance at the wiring harness position of about 1 cm near the A-port adapter cable 2 and the B-port adapter cable 13 near the B-port signal transmission port 12. The transient pulse amplitude is attenuated to a certain extent without significantly affecting the signal transmission quality and efficiency, so as to reduce the indirect coupling energy in the cavity caused by the transient interference pulse entering the shielding shell.

[0060] The A-port signal transmission port 3 and the B-port signal transmission port 12 are shielded connection ports to realize the switching of different signals. The A-port signal transmission port 3 connects the A-port adapter cable 2 and the shielded packaging shell 1; the B-port signal transmission port 12 connects the B-port adapter cable 13 and the shielded packaging shell 1. A preferred implementation is that the A-port signal transmission port 3 and the B-port signal transmission port 12 use a multi-core ECG socket that meets the requirements of multi-line switching, which can prevent reverse insertion and wrong insertion, minimize the aperture of the port, and provide a low-impedance conductive interface connection, which is beneficial to reduce the impact of the opening on the shielding effectiveness of the shielded packaging shell 1. When not in use, the port should be closed with a corresponding model of FGG / EGG metal dust cover.

[0061] The A-port signal transmission port 3 and the B-port signal transmission port 12 are connected to the shielding package shell 1 by fastening screws and applying pressure to the gasket to achieve low impedance fastening connection, such as Figure 2 As shown in the figure, A is the ECG socket; B is the elastic conductive gasket outside the shielding shell; C is the elastic conductive gasket inside the shielding shell, connected to the reference ground of the circuit board; D is the fastening nut. A preferred embodiment is that the connection port impedance is lower than 0.5mΩ.

[0062] The A-port transient pulse limiting unit 4 and the B-port transient pulse limiting unit 11 are circuits or integrated circuit components, which can be single-stage or multi-stage, and can also be dispersed in the circuit. A preferred embodiment is that the A-port transient pulse limiting unit 4 and the B-port transient pulse limiting unit 11 use magnetic beads that match the signal transmission impedance and meet the communication rate requirements. A preferred embodiment is that the impedance characteristic frequency of the circuit or integrated circuit components used by the A-port transient pulse limiting unit 4 and the B-port transient pulse limiting unit 11 should avoid high overlap with the primary and secondary frequencies of the transient interference pulse. The A-port transient pulse limiting unit 4 connects the A-port signal transmission port 3 and the A-port transient pulse isolation unit 5. The B-port transient pulse limiting unit 11 connects the B-port signal transmission port 12 and the B-port transient pulse isolation unit 10.

[0063] The A-port pulse isolation unit 5 and the B-port pulse isolation unit 10 are circuits or integrated electronic components. A preferred embodiment is that the A-port pulse isolation unit 5 and the B-port pulse isolation unit 10 use a pulse isolation circuit or a composite circuit including a signal transformer integrated circuit. A preferred embodiment is that the A-port pulse isolation unit 5 and the B-port pulse isolation unit 10 use a signal-level isolation transformer integrated circuit. By reducing the length and loop area of ​​the coupling harness, the indirect field coupling pulse energy is reduced. In addition, it can also avoid the test sample being subjected to unexpected transient pulses due to the rapid discharge of transient pulse energy at the application port of the device.

[0064] The A-port transient pulse suppression unit 6 and the B-port transient pulse suppression unit 9 are pulse suppression circuits, which can be single-stage or multi-stage, or can be dispersed in the circuit, including pulse suppression integrated circuits, resistors, capacitors, inductors and other components. A preferred embodiment is that the A-port transient pulse suppression unit 6 and the B-port transient pulse suppression unit 9 use pulse suppression integrated circuits with low junction capacitance. A preferred embodiment is that the junction capacitance of the pulse suppression integrated circuit or the pulse suppression period is less than 1pF. A preferred embodiment is that the A-port transient pulse suppression unit 6 and the B-port transient pulse suppression unit 9 are circuits or devices that need to meet the communication requirements of the transmitted signal. A preferred embodiment is that the pulse clamping voltage of the pulse suppression device or the pulse suppression integrated circuit should be lower than 50V, and a multi-stage pulse suppression unit can also be used, and the pulse clamping voltage of the last stage pulse suppression circuit should be lower than 50V. The A-port transient pulse suppression unit 6 is connected to the A-port pulse isolation unit 5 and the A-port filtering and decoupling unit 7. The B-port pulse suppression unit 9 is connected to the B-port pulse isolation unit 10 and the B-port filtering and decoupling unit 11 .

[0065] The A-port filter decoupling unit 7 and the B-port filter decoupling unit 8 mainly realize the filtering and decoupling of electromagnetic interference such as low-amplitude wide-frequency pulses and oscillation waves after pulse suppression. The A-port filter decoupling unit 7 mainly realizes the filtering and decoupling of electromagnetic interference such as low-amplitude, wide-frequency pulses and oscillation waves after pulse suppression by the A-port transient pulse limiting unit 4, the A-port transient pulse isolation unit 5 and the A-port transient pulse suppression unit 6. The B-port filter decoupling unit 8 mainly realizes the filtering and decoupling of electromagnetic interference such as low-amplitude, wide-frequency pulses and oscillation waves after pulse suppression by the B-port transient pulse limiting unit 11, the B-port transient pulse isolation unit 10 and the B-port transient pulse suppression unit 9. The A-port filter decoupling unit 7 and the B-port filter decoupling unit 8 can use circuits composed of common-mode inductors, differential-mode inductors, capacitors, resistors and other components. In high-speed signal applications, the inductor should be less than 100uH, which can be adjusted according to the transmission signal rate.

[0066] The shielding package shell grounding point 14 is the only grounding position of the entire device, and the grounding impedance is as small as possible. A preferred embodiment is that the shielding package shell grounding point 14 uses a copper tinned braid with a width greater than 50 mm, and the grounding impedance should be less than 0.5 mΩ to achieve a lower high-frequency inductance value. A preferred embodiment is that the length of the copper tinned braid is less than 100 mm. The utility model avoids the difference in impedance of various parts of the device to the ground caused by multi-point grounding, and reduces the high-frequency current loop on the surface of the device shell.

[0067] The A-port signal transmission port 3 is connected to the test sample, and the transient pulse coupled from the A-port signal transmission port 3 is pulse suppressed starting from the A-port signal transmission port 3 .

[0068] The B-port signal transmission port 12 is connected to an auxiliary device and is the output port after transient pulse suppression and decoupling. It can also prevent the transient pulse voltage at the auxiliary device end from being transmitted to the A-port signal transmission port 3.

[0069] The A-port signal transmission port 3 and the B-port signal transmission port 12 can be used interchangeably.

[0070] The A-port transient pulse limiting unit 4, the A-port transient pulse isolation unit 5, the A-port transient pulse suppression unit 6, the A-port filtering and decoupling unit 7, the B-port filtering and decoupling unit 8, the B-port transient pulse suppression unit 9, the B-port transient pulse isolation unit 10, and the transient pulse limiting unit 11 can be integrated into the PCB circuit board, or can be independent units and shielded and packaged. If independent shielded packaging is used, each unit is connected by a shielded harness.

[0071] The PCB circuit board should be a multi-layer board. A preferred implementation is that the number of layers of the PCB circuit board should be no less than 4, and copper cladding should be used to isolate different layers to avoid crosstalk. A preferred implementation is to minimize the length and loop area of ​​the traces exposed to the top and bottom layers of the PCB circuit board.

[0072] The circuit board grounding wire connects the PCB circuit board and the outer shielding package shell 1, and is used to release transient pulses to the reference ground. A preferred implementation is that the wire diameter of the circuit board grounding wire is greater than 1mm, so that the circuit board grounding wire has a lower high-frequency inductance value during the high-frequency transient current release process.

[0073] The A-port signal transmission port 3 and the B-port signal transmission port 12 are fastened to the mounting holes of the shielding package shell 1. A preferred implementation is that the pressure of the mounting nut is greater than 2 MPa and the impedance is less than 0.5 mΩ.

[0074] Example 1

[0075] See also Figure 3 This is the circuit diagram of the device of this implementation case. The circuit diagram has a left-right symmetrical structure. Parts A1 and B1 are respectively the transient pulse limiting unit 4 of port A and the transient pulse limiting unit 11 of port B, which are magnetic beads with an impedance of 120 ohms. Parts A2 and B2 are respectively the transient pulse isolation unit 5 of port A and the transient pulse isolation unit 10 of port B, which are circuits composed of Ethernet port transformers, resistors, capacitors, etc. Parts A3 and B3 are respectively the transient pulse suppression unit 6 of port A and the transient pulse suppression unit 9 of port B, which are composed of highly integrated high-speed signal port transient pulse suppression circuits and impedance-matched inductors, which optimize the start-up and shutdown time of the two transient pulse suppression integrated circuits and achieve better transient pulse suppression effects. Parts A4 and B4 are respectively the filtering and decoupling unit 7 of port A and the filtering and decoupling unit 8 of port B, which are differential mode inductors of nH to μH level. Part AB is the differential mode pulse suppression part of the pulse suppression unit. Parts OA and OB are respectively magnetic beads added to the port adapter.

[0076] Example 2

[0077] like Figure 4 As shown, according to ISO 10605:2023 and GB / T19951-2019, the test sample is connected to the A-port signal transmission port 2 of the device, and the auxiliary equipment is connected to the B-port signal transmission port 13. The entire system disclosed in the utility model is placed on the test bench, and the connecting wire adopts an insulating support with a thickness of (50±5) mm (the dielectric constant of the supporting material is less than 1.4). The transient pulse suppression device is connected to the reference ground plane.

[0078] Contact discharge is performed at the test point, and the test voltage is (1~15) kV. The test sample and the auxiliary equipment can communicate normally without interruption. Contact discharge is performed on the test sample, and the test voltage is (15-30) kV. The test sample and the auxiliary equipment are placed 10 cm above the ground reference plane or outside the reference ground plane or in a metal shielding box. The test sample and the auxiliary equipment can communicate normally without interruption. The results show that the utility model can effectively suppress electrostatic pulses. (Note: High-amplitude transient currents and high-intensity electromagnetic fields will be generated during the charging and discharging and electrostatic pulse suppression process of the electrostatic pulse generator. The higher the test level, the higher the amplitude of the transient current and the electromagnetic field, and the wider the frequency, which will cause the test equipment to be interfered by the electrostatic pulse field through spatial field coupling. In order to avoid the influence of the coupling field of the reference ground plane on the test equipment, the above treatment is performed. The main protection of the auxiliary equipment by this device is mainly for transient pulses coupled by harness conduction.)

[0079] Example 3

[0080] According to the standards of ISO 10605:2023 and GB / T19951-2019, Figure 5 Arrange to lead out the discharge connector at one end of the pulse suppression module, and select the corresponding pin at the other end to transfer to the outside of the shielded room through the coaxial line of the BNC interface for testing. Transfer through the wall of the shielded room, and use an oscilloscope to collect the pulse suppression residual voltage outside the shielded room. Pin 1, pin 2, pin 3 and pin 6 are equivalent in the circuit. Select pin 2 for verification, discharge 10 times for each test level and polarity, and use an oscilloscope to collect the maximum peak value of positive and negative pulses, such as Figure 6 shown. Figure 6 (A) and (B) are the pulse suppression residual voltage waveforms of +1kV and -1kV respectively; Figure 6 (C) and (D) are the pulse suppression residual voltage waveforms of +2kV and -2kV respectively; Figure 6 (E) and (F) are the pulse suppression residual voltage waveforms of +6kV and -6kV respectively; Figure 6 (G) and (H) are the pulse suppression residual voltage waveforms of +10kV and -10kV respectively; Figure 6 (I) and (J) are the pulse suppression residual voltage waveforms of +15kV and -15kV respectively; Figure 6 (K) and (L) in the figure are the pulse suppression residual voltage waveforms of +20kV and -20kV respectively; Figure 6 The (M) and (N) in the figure are the pulse suppression residual voltage waveforms of +30kV and -30kV respectively. The pulse suppression residual voltage results are shown in Table 1. Figure 6 The results in Table 1 show that the electrostatic transient pulses of 1-30kV are effectively suppressed, with the maximum suppression reaching 42.3dB.

[0081] Table 1 Statistics of residual voltage suppression of electrostatic discharge pulse

[0082]

[0083] Example 4

[0084] According to the standard requirements of ISO 7637-3:2016 (GB / T 21437.3-2021), Figure 7 According to the layout requirements, the DCC injection method is adopted. Interference is applied to Pin2 of the transient pulse suppression device, and the pulse suppression residual voltage is collected by an oscilloscope at the other end. The interference levels applied are ±100V, ±200V, ±600V, and ±1000V respectively. The corresponding residual voltage waveform is as follows Figure 8 shown. Figure 8 (A) and (B) in the figure are the pulse suppression residual voltages of +100V and -100V respectively, and the absolute values ​​of the maximum residual voltages are 1.5V and 1.8V respectively; Figure 8 (C) and (D) in the figure are the pulse suppression residual voltages of +200V and -200V respectively, and the absolute values ​​of the maximum residual voltages are 3.2V and 4.2V respectively; Figure 8 (E) and (F) in the figure are the pulse suppression residual voltages of +600V and -600V respectively, and the absolute values ​​of the maximum residual voltages are 6.7V and 8.4V respectively; Figure 8 (G) and (H) in the figure are the pulse suppression residual voltages of +1000V and -1000V respectively, and the absolute values ​​of the maximum residual voltages are 9.3V and 11.4V respectively. Figure 8 As shown in Table 2, the transient pulse voltage is effectively suppressed.

[0085] Table 2 Statistics of transient fast pulse suppression residual voltage

[0086]

[0087] Example 5

[0088] like Fig. 9 As shown, according to the requirements of the standards RFC 2544-1999 "Basic Test Methods for Network Interconnection Equipment" and GB / T21671-2018 "Acceptance Test Methods for Local Area Network (LAN) Systems Based on Ethernet Technology", a network analyzer is used to test the 10Mbps / 100Mbps communication performance of the transient pulse suppression device of the utility model, and the results are shown in Table 3. The utility model device will not have a significant impact on 10Mbps / 100Mbps Ethernet communication.

[0089] Table 3 10Mbps / 100Mbps Ethernet port communication performance

[0090]

[0091] *: The minimum packet loss rate division value of the network tester used in this embodiment is 0.1%.

Claims

1. A multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing, characterized in that: include: Shielded packaging shell, A-port adapter cable, A-port signal transmission port, A-port transient pulse limiting unit, A-port transient pulse isolation unit, A-port transient pulse suppression unit, A-port filtering and decoupling unit, B-port filtering and decoupling unit, B-port transient pulse suppression unit, B-port transient pulse isolation unit, B-port transient pulse limiting unit, B-port signal transmission port, B-port adapter cable, and a shielded packaging shell grounding port connected to the shielded packaging shell; The A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit and the A-port filtering and decoupling unit are connected in sequence, the A-port transient pulse limiting unit is connected to the A-port signal transmission port, and the A-port signal transmission port is connected to the A-port adapter cable; The B-port filter decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are connected in sequence, the B-port filter decoupling unit is connected to the A-port filter decoupling unit, the B-port transient pulse limiting unit is connected to the B-port signal transmission port, and the B-port signal transmission port is connected to the B-port adapter cable; The A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are integrated into a circuit board, and the circuit board is encapsulated in a shielding packaging shell, and the shielding packaging shell is provided with an A-port signal transmission port and a B-port signal transmission port; Or the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are located on respective independent circuit boards, and each circuit board is encapsulated in a shielding packaging shell, wherein the shielding packaging shell encapsulating the A-port transient pulse limiting unit is provided with an A-port signal transmission port, and the shielding packaging shell encapsulating the B-port transient pulse limiting unit is provided with a B-port signal transmission port; Or at least two of the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit, the A-port filtering and decoupling unit, the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit and the B-port transient pulse limiting unit are freely combined and packaged in a common shielding packaging shell in a combined form, wherein the shielding packaging shell encapsulating the A-port transient pulse limiting unit is provided with an A-port signal transmission port, and the shielding packaging shell encapsulating the B-port transient pulse limiting unit is provided with a B-port signal transmission port.

2. A multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing as claimed in claim 1, characterized in that: The shielding packaging shell is a three-dimensional fully enclosed metal shell.

3. A multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing as claimed in claim 1, characterized in that: The A-port adapter, the A-port signal transmission port, the A-port transient pulse limiting unit, the A-port transient pulse isolation unit, the A-port transient pulse suppression unit and the A-port filtering and decoupling unit are symmetrical with the B-port filtering and decoupling unit, the B-port transient pulse suppression unit, the B-port transient pulse isolation unit, the B-port transient pulse limiting unit, the B-port signal transmission port and the B-port adapter.

4. The multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing according to claim 1, characterized in that: The A-port adapter wire is close to the A-port signal transmission port and the B-port adapter wire is close to the B-port signal transmission port, allowing the nearest harness position to be installed to increase the magnetic beads that match the transmission signal impedance.

5. The multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing according to claim 1, characterized in that: The A-port signal transmission port and the B-port signal transmission port adopt multi-core FGG / EGG sockets that meet the requirements of multi-line switching.

6. The multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing according to claim 1, characterized in that: The grounding point of the shielding package shell adopts a copper tinned braided belt with a width greater than 5 mm, and the grounding impedance is less than 0.5 mΩ.

7. The multifunctional transient electromagnetic pulse suppression device for electromagnetic compatibility testing according to claim 1, characterized in that: The impedance of the ground connection line between the circuit board and the shielding packaging shell is less than 0.5mΩ, the line diameter is greater than 2mm, and the length is less than 10mm.

Images