Computer interface lightning electromagnetic pulse and electro strength protection device

Abstract

This invention discloses a lightning electromagnetic pulse (MEP) and dielectric strength protection device for computer interfaces, belonging to the field of strong electromagnetic pulse protection. This invention proposes a lightning MEP and dielectric strength protection device for computer interfaces, providing protection for computer power supplies, networks, USB, serial communication, digital inputs, and analog inputs. This invention employs a design that simultaneously protects against differential-mode and common-mode interference, combining transient protection with filtering. The lightning protection design is mainly divided into differential-mode protection and common-mode protection. The differential-mode protection design mainly consists of components such as varistors, gas discharge tubes, resistors, and transient suppression diodes; the common-mode protection design mainly consists of components such as varistors, gas discharge tubes, transient suppression diodes, and capacitors. This invention can protect against lightning MEPs while meeting the dielectric strength requirements of computers.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of strong electromagnetic pulse protection, and particularly relates to a lightning electromagnetic pulse and anti-electric strength protection device for a computer interface. BACKGROUND

[0002] Computers are applied to various aerospace systems, and the systems go through multiple stages such as factory testing, transportation, waiting for launch, and take-off, and there is a risk of being struck by lightning in each stage, and there is also a possibility of being struck by natural lightning or induced lightning during atmospheric flight. When the system is struck by lightning or lightning discharge occurs nearby, a lightning-induced electromagnetic field is formed inside the system, and a lightning-induced current and an induced voltage are coupled to be generated, which are conducted to the computer through power lines, signal lines and the like, and may cause the computer to have abnormal interface circuits, "reset", "dead machine", device damage and other forms of failure, causing system data errors, positioning lockout, communication interruption and other faults, and eventually causing serious consequences.

[0003] Typical interface types of the computer include power supply, network, USB, serial communication, switching value, analog value and the like. At present, lightning protection for the computer interface is mostly achieved by discharging through gas discharge tubes, voltage-dependent resistors, transient suppression diodes and the like, but the lightning protection design composed of the transient devices will cause the anti-electricity at the interface to no longer meet the safety requirements of the whole machine, thereby increasing the safety risk of the computer. The anti-electric strength test in the computer electrical interface test project mainly examines the isolation degree of the computer electrical interface to the ground. The anti-electric strength test conditions mainly include three parameters of test voltage, duration and protection current, which represent the safety characteristics of each measurement point to the shell. The anti-electric test is a direct current high voltage or an alternating current (50Hz / 60Hz) high voltage, and the injection time is 1min and the rising time is 5s. During the test process, the computer should not have any breakdown, sparking or damage and the like, and the capacitance between the line and the ground enables the computer to meet the anti-electric test requirements; the lightning electromagnetic pulse is usually a us-level transient pulse, and the energy is mainly concentrated below 10MHz. When the lightning electromagnetic pulse is generated, the transient protection device is started to discharge the lightning electromagnetic pulse, so as to protect the subsequent circuit from being affected and damaged by the pulse. The lightning electromagnetic pulse protection design is divided into line-line protection and line-ground protection, and finally the energy of the electromagnetic pulse is discharged to the shell ground, which is contrary to the above anti-electric strength requirement.

[0004] In order to meet the lightning protection design of the anti-electric requirement, there are three common methods, the first method is to select a device with a starting voltage greater than the anti-electric voltage requirement; the second method is to not design a device for discharging to the ground to meet the anti-electric requirement, and only design lightning protection devices between differential lines; the third method is to only perform anti-electric tests when the whole machine is not designed for lightning protection, and the anti-electric index is no longer examined after the lightning protection circuit is added. Each of the above solutions has certain safety hazards. SUMMARY

[0005] The present application aims at overcoming the above-mentioned defects of the prior art, and provides a computer interface lightning electromagnetic pulse and anti-electric strength protection device.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A computer interface lightning electromagnetic pulse and anti-electric strength protection device, comprising a differential mode protection module and a common mode protection module;

[0008] The differential mode protection module is composed of a primary differential mode protection unit, an EMI filter and decoupling unit and a secondary differential mode protection unit, the primary differential mode protection unit is used for discharging the received lightning electromagnetic pulse interference; the EMI filter and decoupling unit is used for suppressing the differential mode interference and realizing decoupling at the same time; and the secondary differential mode protection unit is used for discharging the residual voltage.

[0009] The common mode protection module comprises a primary common mode protection unit, an EMI filter and decoupling unit and a secondary common mode protection unit, the primary common mode protection unit is used for discharging the common mode transient interference and discharging the alternating component at the same time; the EMI filter and decoupling unit is used for suppressing the common mode inductance; and the secondary common mode protection unit is used for discharging the residual voltage and clamping the voltage to a predetermined level.

[0010] Further, the primary differential mode protection unit is a gas discharge tube or a gas discharge tube connected in series with a varistor between the power supply or the signal line, if the circuit operating voltage is greater than the arc voltage of the gas discharge tube, then there is a varistor connected in series;

[0011] The EMI filter and decoupling unit adopts a combination of differential mode capacitors and common mode inductance leakage, resistance or thermistor to suppress the differential mode interference and realize decoupling at the same time.

[0012] The secondary differential mode protection unit is a transient suppression diode or semiconductor discharge tube connected in parallel between the power supply or the signal line.

[0013] Further, the primary common mode protection unit is a gas discharge tube connected in series with a varistor and a high-voltage capacitor between the power supply or the signal line.

[0014] The EMI filter and decoupling unit is mainly suppressed by the common mode inductance for the common mode interference.

[0015] The secondary common mode protection unit is a transient suppression diode or semiconductor discharge tube connected in parallel between the power supply line or the signal line and the ground, and then connected to the ground through the high-voltage capacitor of the primary common mode protection unit.

[0016] Further, when the interface is a power interface, one end of a first voltage-dependent resistor and one end of a first differential mode capacitor are connected to the power +, the first voltage-dependent resistor is connected in series with a first gas discharge tube, the other end of the first gas discharge tube is connected to the power -, the power + and the power - are further connected with a first differential mode capacitor, one side of a first common mode inductor is connected to the power + and the power -, the other side of the first common mode inductor is connected to the power +1 and the power -1 respectively, wherein the power + and the power +1 are two ends of an inductor coil, the power - and the power -1 are two ends of another inductor coil;

[0017] The second differential mode capacitor and a first transient voltage suppression diode are further connected in parallel between the power +1 and the power -1.

[0018] One end of a second voltage-dependent resistor is connected to the power -, the other end of the second voltage-dependent resistor is connected in series with a second gas discharge tube, one end of a second transient voltage suppression diode is connected to the power -1, the other end of the second transient voltage suppression diode and the other end of the second gas discharge tube are both connected to one end of a first capacitor, the other end of the first capacitor is connected to the ground.

[0019] Further, when the interface is a network interface, a thermistor is connected in series on each signal line, one end of a gas discharge tube is connected to the input end of each signal line, one end of a semiconductor discharge tube is connected to the output end of each signal line, the other end of the gas discharge tube and the other end of the semiconductor discharge tube are both connected to one end of a second discharge capacitor, the other end of the second discharge capacitor is connected to the ground.

[0020] Further, when the interface is a USB interface, a thermistor is connected in series on the DC power supply line and the high-speed signal line, one end of a gas discharge tube is connected to the input end of the DC power supply and the input end of the high-speed signal line, one end of a transient voltage suppression diode is connected to the output end of the DC power supply, one end of a semiconductor discharge tube is connected to the output end of the high-speed signal line, the other end of the gas discharge tube, the other end of the transient voltage suppression diode and the other end of the semiconductor discharge tube are all connected to one end of a third discharge capacitor, the other end of the third discharge capacitor is connected to the ground.

[0021] Furthermore, when the interface is an RS422 interface, thermistors are connected in series on the differential lines and the signal ground line respectively. One end of a gas discharge tube is connected to each of the four differential signal lines R+, R-, T+, and T-. The other end of the gas discharge tube is connected to the signal ground line RS-GND. The signal ground line RS-GND is also connected to the nineteenth gas discharge tube. One end of a transient voltage suppression diode is connected to each of the four differential signal lines R+_1, R-_1, T+_1, and T-_1. The other end of each transient voltage suppression diode is connected to the signal ground line RS-GND_1. The signal ground line RS-GND_1 is also connected to one end of the ninth transient voltage suppression diode. The other end of the nineteenth gas discharge tube GDT19 and the other end of the ninth transient voltage suppression diode are both connected to one end of the fourth bleeder capacitor. The other end of the fourth bleeder capacitor is grounded.

[0022] Furthermore, when the interface is a digital input interface, a second varistor and a twentieth gas discharge tube are connected in series between the input terminals A and B of the digital input. Input terminals A and B are respectively connected to the two ends of one side of the coil of the second common mode inductor. The two ends of the other side of the coil of the second common mode inductor are respectively connected to the output terminals C and D. A tenth transient voltage suppressor diode is connected in parallel between the output terminals C and D.

[0023] One end of the twenty-first gas discharge tube is also connected to the input terminal B, and one end of the eleventh transient voltage suppression diode is also connected to the output terminal D. The other ends of the twenty-first gas discharge tube and the eleventh transient voltage suppression diode are both connected to one end of the fifth discharge capacitor, and the other end of the fifth discharge capacitor is grounded.

[0024] Furthermore, when the interface is an analog interface, the eighteenth and nineteenth thermistors are connected in series on the two analog lines respectively. The twenty-second gas discharge tube is connected between YL and AGND. The twelfth transient voltage suppression diode is connected between YL_1 and AGND_1. One end of the twenty-third gas discharge tube is also connected to AGND. One end of the thirteenth transient voltage suppression diode is also connected to AGND_1. The other end of the thirteenth transient voltage suppression diode and the other end of the twenty-third gas discharge tube are both connected to one end of the sixth bleeder capacitor. The other end of the sixth bleeder capacitor is grounded.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention proposes a lightning electromagnetic pulse (MEP) and dielectric strength protection device for computer interfaces. It provides protection against both lightning MEPs and meets the computer's dielectric strength requirements. The invention employs a design that simultaneously protects against differential-mode and common-mode interference, combining transient protection with filtering. This allows the computer to simultaneously meet the requirements for both lightning MEP protection and dielectric strength. This invention is applicable to various types of computer interface circuits. It achieves both survivability and safety under lightning MEP attacks while simultaneously meeting dielectric strength requirements, thus improving the electromagnetic security and reliability of computers. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the lightning electromagnetic pulse protection structure of the present invention;

[0028] Figure 2 This invention relates to a power supply lightning / electric shock protection design.

[0029] Figure 3 Designed for network lightning / electric shock protection;

[0030] Figure 4 Designed for USB lightning / electric shock protection;

[0031] Figure 5 Designed for RS422 lightning / electric shock protection;

[0032] Figure 6 Designed for lightning / electric shock protection of switching inputs;

[0033] Figure 7 Designed for analog lightning / electric shock protection. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] The present invention will now be described in further detail with reference to the accompanying drawings:

[0037] According to the detailed implementation scheme of the present invention, lightning protection and dielectric strength design are carried out for typical computer signal types, including power signals, network signals, USB signals, serial port (RS422) signals, switch signals, and analog signals. The specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

[0038] This invention provides a power supply lightning / surface protection design method, the structural schematic of which is shown below. Figure 1 As shown. Lightning protection design is mainly divided into differential mode protection and common mode protection. Differential mode protection design mainly consists of components such as varistors, gas discharge tubes, resistors, and transient suppression diodes; common mode protection design mainly consists of components such as varistors, gas discharge tubes, transient suppression diodes, and capacitors.

[0039] (1) Differential mode protection

[0040] It is mainly divided into three levels of protection. The first level of protection is mainly composed of gas discharge tubes and varistors. The second level is mainly composed of EMI filter circuits and decoupling circuits composed of differential mode capacitors, common mode inductors and thermistors. The third level of protection is composed of transient suppression diodes and semiconductor discharge tubes.

[0041] Primary differential mode protection involves connecting a gas discharge tube and a varistor in series between the power or signal lines. Gas discharge tubes have the advantage of high current carrying capacity, but they are only suitable for circuits where the circuit voltage is lower than the device's arc voltage (around 10V). If the circuit operating voltage is higher than the arc voltage of the gas discharge tube, the circuit will remain short-circuited after the lightning electromagnetic pulse discharges and cannot be restored. Varistors are clamping devices, and their clamping voltage is much higher than the circuit operating voltage. Using them in series can compensate for each other, making their advantages more pronounced. The second stage is EMI filtering and decoupling design, using differential mode capacitors and the leakage inductance, resistance, or thermistors of common mode inductors to suppress differential mode interference and achieve decoupling, allowing the primary protection circuit to function. The third stage of differential mode protection is achieved by connecting transient suppression diodes or semiconductor discharge tubes in parallel between the power or signal lines.

[0042] (2) Common mode protection

[0043] It is mainly divided into three levels of protection. The first level of protection consists of a gas discharge tube, a varistor, and a high-voltage capacitor. The second level consists of an EMI filter circuit and a decoupling circuit consisting of a differential-mode capacitor, a common-mode inductor, and a thermistor. The third level of protection consists of a transient suppression diode and the high-voltage capacitor in the first level.

[0044] The primary common-mode protection stage involves connecting a gas discharge tube between the power or signal line and then connecting it in series with a varistor and a high-voltage capacitor. The gas discharge tube and varistor discharge common-mode transient interference, while the capacitor discharges AC components. The second stage is for EMI filtering and decoupling; common-mode interference is mainly suppressed by a common-mode inductor. The third stage of common-mode protection involves connecting transient suppression diodes or semiconductor discharge tubes in parallel between the power or signal line and ground, and then connecting them to ground through the high-voltage capacitor from the primary protection stage. This provides further protection against residual voltage from the previous stage, clamping the voltage to a predetermined level and effectively protecting sensitive components in the circuit.

[0045] like Figure 2 As shown, the differential mode protection of the power supply lightning / electric shock protection design includes four parts: primary differential mode protection, differential mode filtering, decoupling, and secondary differential mode protection. The common mode protection includes four parts: primary common mode protection, common mode filtering, secondary protection, and high frequency discharge.

[0046] The primary differential mode protection consists of a first varistor MOV1 and a first gas discharge tube GDT1. The first varistor MOV1 is a MYG20G10K820, with one end connected to the power supply + and the other end connected to the first gas discharge tube GDT1. The first gas discharge tube GDT1 is a BC091N-H, and after being connected to the first varistor MOV1, its other end is connected to the power supply -. The differential mode filtering mainly consists of a first differential mode capacitor Cx1, the leakage inductance of the first common mode inductor Lcm1, and a second differential mode capacitor Cx2. The first differential mode capacitor Cx1 is a CT41G-1210-X7R-100V-105-K(N), with one end connected to the power supply + and the other end connected to the power supply - after the primary differential mode protection. The first common mode inductor Lcm1 is a PCFC2312_102, with one end connected to the power supply + / power supply - and the other end connected to the power supply +_1 / power supply -_1. Since the common mode inductor is a non-ideal component... Loop 1 and Loop 2 cannot achieve a completely symmetrical structure, and the generated magnetic flux cannot be completely canceled, forming leakage inductance. This leakage inductance serves two purposes: firstly, it suppresses the differential-mode interference present in the circuit, and secondly, it achieves decoupling. When encountering transient high-pulse interference, the primary protection is activated first, thus protecting the secondary protection circuit and the load circuit. The second differential-mode capacitor Cx2 is the same model as the first differential-mode capacitor Cx1 and is connected after the common-mode inductor. Together with the leakage inductance of the preceding differential-mode capacitor and common-mode inductor, it forms a Π-type filter to suppress the differential-mode component in the interference. The secondary differential-mode protection is composed of the first transient voltage suppression diode TVS1, model SY169CA. One end of the first transient voltage suppression diode TVS1 is connected to power supply +_1, and the other end is connected to power supply -_1, achieving effective protection against electromagnetic pulse interference in the differential-mode circuit.

[0047] Primary common-mode protection is achieved by a second varistor MOV2 and a second gas discharge tube GDT2. The second varistor MOV2 is a MYG20G10K820, with one end connected to the power supply and the other end connected to the second gas discharge tube GDT2. The second gas discharge tube GDT2 is a BX151N, with its other end connected to one end of a capacitor Cy1 (CT41G-2220-X7R-1KV-0.1uF-K(N)). Common-mode filtering is achieved by a 1mH first common-mode inductor Lcm1. Secondary common-mode protection is achieved by a second transient voltage suppressor diode TVS2 (SY169CA), with one end connected to the power supply and the other end connected to the junction of the second gas discharge tube GDT2 and the first capacitor Cy1. High-frequency discharge is achieved by the first capacitor Cy1, with the other end connected to ground, discharging the high-frequency components of common-mode interference to ground.

[0048] like Figure 3As shown, the common-mode protection and high-frequency discharge circuit of the network lightning / electromagnetic protection design comprises four parts: primary protection, decoupling, secondary protection, and high-frequency discharge. Primary protection is designed for each signal on the network signal lines. The third to tenth gas discharge tubes (GDT3 to GDT10) are the same model, BC091N-H. One end of each tube is connected to one of the eight network signal cables, and the other end is connected together to one end of the second capacitor Cy2, achieving primary common-mode protection. The first to eighth thermistors (PPTC1 to PPTC8) are the same model, SMD1206R016SF30V, connected in series to the eight network signal cables for decoupling, satisfying the requirement that the primary protection circuit conducts first when a lightning electromagnetic pulse occurs. Design requirements: The secondary protection design consists of the first to eighth semiconductor discharge tubes (TSS1 to TSS8). Ordinary TVS diodes have large junction capacitances, which can easily lead to high-speed signal distortion. The first to eighth semiconductor discharge tubes (TSS1 to TSS8) are of the same model, SY159CA. One end of each tube is connected to the eight network signal cables after the thermistor, and the other end is connected to the gas discharge tube and then to one end of the second bleeder capacitor Cy2. The second bleeder capacitor Cy2 is model CT41G-2220-X7R-1KV-0.1uF-K(N). High-frequency bleeding is achieved by the second bleeder capacitor Cy2. The other end of the second bleeder capacitor Cy2 is connected to ground, providing a path for the high-frequency components of common-mode interference to be discharged to ground. Differential-mode protection of the network signal is mainly achieved by the above two common-mode protection series circuits, satisfying the network signal function while also achieving lightning / electric shock protection design.

[0049] like Figure 4As shown, the USB lightning / electric shock protection design is similar to that of the network signals mentioned above. However, since the USB DATA+ and DATA- signals are high-speed signals and the 5V power supply is a DC power supply, different protection devices are selected for the two types of signals. The primary protection and decoupling circuit designs are the same. The primary protection circuit consists of the eleventh to fourteenth gas discharge tubes GDT11 to GDT14 of the same model, model BC091N-H, which are connected in parallel with ground through the third bleeder capacitor Cy3. The decoupling circuit consists of the ninth to twelfth thermistors PPTC9 to PPTC12 of the same model, model SMD1206R016SF30V, connected in series between the power supply line and the signal line. The power supply for the secondary protection circuit uses the third transient voltage suppressor diode TV. Protection is achieved using S3 and the fourth transient voltage suppressor diode TVS4, model SY142CA. For high-speed signals, protection is achieved using the ninth semiconductor discharge diode TSS9 and the tenth semiconductor discharge diode TSS10, model BS0060N-2C, which have smaller junction capacitance. The secondary protection devices are connected in parallel with ground through the third discharge capacitor Cy3, model CT41G-2220-X7R-1KV-0.1uF-K(N), which satisfies the USB communication function while also providing lightning / electric shock protection design.

[0050] like Figure 5 As shown, the lightning / electric shock protection design for serial port signals follows the above design approach. Taking RS422 as an example, the signal consists of two pairs of differential signals (receive and transmit) and one signal ground. Primary protection is mainly divided into two parts. The first part involves connecting the fifteenth to eighteenth gas discharge tubes (GDT15 to GDT18, model BC091N-H) in parallel between the two pairs of differential signal lines and the signal ground. Protection between the differential pairs is mainly achieved by connecting the two protection circuits to the signal ground in series. The second part connects the signal ground to the earth via the nineteenth gas discharge tube (GDT19) through the fourth bleeder capacitor (Cy4). The nineteenth gas discharge tube (GDT19) is model BC091N-H, and the fourth bleeder capacitor (Cy4) is model CT41G-2220-X7R-1KV-0.1uF-K(N). This achieves primary differential and common-mode protection for the serial port. The decoupling circuit consists of the thirteenth to seventeenth thermistors PPTC13 to PPTC17, model SMD1206R016SF30V, connected in series between the differential line and the signal ground line. The secondary protection is also divided into two parts: differential signal to signal ground and signal ground to earth. The differential signal to signal ground is composed of the fifth transient voltage suppressor diodes TVS5 to TVS8, model SY142CA. The signal ground and earth are connected by TVS9 through the fourth bleeder capacitor Cy4, model SY159CA. This design satisfies the RS422 serial communication function and also implements lightning / electric shock protection design.

[0051] like Figure 6 As shown, the protection design for switching signals is similar to that for power supply protection, consisting of primary differential-mode protection, primary common-mode protection, filtering and decoupling, secondary differential-mode protection, secondary common-mode protection, and high-frequency discharge. Primary differential-mode protection is achieved by connecting the second varistor MOV2 and the twentieth gas discharge tube GDT20 in series between points A and B. The second varistor MOV2 is model MYG20G10K820, and the twentieth gas discharge tube GDT20 is model BC091N-H. Primary common-mode protection is achieved by connecting the twenty-first gas discharge tube GDT21 to ground through the fifth discharge capacitor Cy5. The twenty-first gas discharge tube GDT21 is model BC091N-H, and the fifth discharge capacitor Cy5 is model CT41G-2220-X. 7R-1KV-0.1uF-K(N); The leakage inductance of the second common-mode inductor Lcm2 enables differential-mode filtering and decoupling. The second common-mode inductor Lcm2 is model BPCFC1211S_102, and the common-mode inductance enables common-mode filtering. Secondary differential-mode protection is achieved by the first transient voltage suppressor diode TVS10, model SY169CA. Secondary common-mode protection is achieved by the first transient voltage suppressor diode TVS11 connected to ground through the fifth bleeder capacitor Cy5, model SY169CA. High-frequency bleeding is mainly achieved by the AC-passing / DC-blocking of the fifth bleeder capacitor Cy5, satisfying the switching operation while achieving lightning / electric shock protection design.

[0052] like Figure 7As shown, the primary differential mode protection for the analog signal is achieved by connecting the 22nd gas discharge tube (GDT22) in parallel between YL and AGND. The primary common mode protection is achieved by connecting the 23rd gas discharge tube (GDT23) in parallel between AGND and ground through the 6th discharge capacitor (Cy6). The 22nd and 23rd gas discharge tubes (GDT22 and GDT23) are of model BC091N-H. Decoupling is achieved by connecting the 18th and 19th thermistors (PPTC18 and PPTC19) in series between the YL and AGND lines. The 18th and 19th thermistors (PPTC18 and PPTC19) are of model SMD1206. R016SF30V; Secondary differential mode protection is achieved by connecting the twelfth transient voltage suppressor diode TVS12 in parallel between YL_1 and AGND_1. Secondary common mode protection is achieved by connecting the thirteenth transient voltage suppressor diode TVS13 to ground through the sixth bleeder capacitor Cy6. High-frequency bleedering is mainly achieved by the sixth bleeder capacitor Cy6. The twelfth transient voltage suppressor diode TVS12 is model SY142CA, the thirteenth transient voltage suppressor diode TVS13 is model SY159CA, and the sixth bleeder capacitor Cy6 is model CT41G-2220-X7R-1KV-0.1uF-K(N). This design satisfies analog communication requirements while providing lightning / electric shock protection.

[0053] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A computer interface lightning electromagnetic pulse and dielectric strength protection device, characterized in that, Includes differential mode protection modules and common mode protection modules; The differential mode protection module consists of a primary differential mode protection unit, an EMI filtering and decoupling unit, and a secondary differential mode protection unit. The primary differential mode protection unit is used to discharge received lightning electromagnetic pulse interference; the EMI filtering and decoupling unit is used to suppress differential mode interference and simultaneously achieve decoupling; and the secondary differential mode protection unit is used to discharge residual voltage. The common-mode protection module includes a primary common-mode protection unit, an EMI filtering and decoupling unit, and a secondary common-mode protection unit. The primary common-mode protection unit is used to discharge common-mode transient interference and AC components. The EMI filtering and decoupling unit is used to suppress common-mode interference. The secondary common-mode protection unit is used to discharge residual voltage and clamp the voltage to a predetermined level. The primary differential mode protection unit is a gas discharge tube or a gas discharge tube connected in series with a varistor between the power supply or signal line. If the circuit operating voltage is greater than the arc voltage of the gas discharge tube, a varistor is connected in series. The EMI filtering and decoupling unit uses a combination of leakage inductance of differential-mode capacitors and common-mode inductors, along with resistors or thermistors, to suppress differential-mode interference while simultaneously achieving decoupling. The secondary differential mode protection unit is a transient suppression diode or semiconductor discharge tube connected in parallel between the power supply or signal line; The primary common-mode protection unit consists of a gas discharge tube connected between the power supply or signal line and a varistor and a high-voltage capacitor connected in series. The EMI filtering and decoupling unit primarily suppresses common-mode interference using common-mode inductors; The secondary common-mode protection unit consists of a transient suppression diode or a semiconductor discharge tube connected in parallel between the power line or signal line and ground, and then connected to ground through the high-voltage capacitor of the primary common-mode protection unit.

2. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is a power interface, one end of the first varistor and the first differential mode capacitor are connected to the power supply +. The first varistor is connected in series with the first gas discharge tube, and the other end of the first gas discharge tube is connected to the power supply -. The first differential mode capacitor is also connected between the power supply + and the power supply -. The power supply + and the power supply - are respectively connected to one side of the first common mode inductor, and the other side of the first common mode inductor is respectively connected to the power supply +_1 and the power supply -_1. The power supply + and the power supply +_1 are the two ends of one inductor coil, and the power supply - and the power supply -_1 are the two ends of another inductor coil. A second differential mode capacitor and a first transient voltage suppression diode are connected in parallel between power supply +1 and power supply -1; One end of the power supply is connected to the second varistor, and the other end of the second varistor is connected in series with the second gas discharge tube. One end of the power supply is connected to the second transient voltage suppression diode, and the other ends of the second transient voltage suppression diode and the second gas discharge tube are both connected to one end of the first capacitor. The other end of the first capacitor is connected to ground.

3. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is a network interface, a thermistor is connected in series on each signal line, one end of a gas discharge tube is connected to the input end of each signal line, one end of a semiconductor discharge tube is connected to the output end of each signal line, and the other end of the gas discharge tube and the other end of the semiconductor discharge tube are both connected to one end of the second bleeder capacitor, and the other end of the second bleeder capacitor is grounded.

4. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is a USB interface, a thermistor is connected in series on both the DC power supply line and the high-speed signal line. The input terminal of the DC power supply and the input terminal of the high-speed signal line are respectively connected to one end of the gas discharge tube. The output terminal of the DC power supply is respectively connected to one end of the transient voltage suppression diode. The output terminal of the high-speed signal line is respectively connected to one end of the semiconductor discharge tube. The other end of the gas discharge tube, the other end of the transient voltage suppression diode, and the other end of the semiconductor discharge tube are all connected to one end of the third bleeder capacitor. The other end of the third bleeder capacitor is grounded.

5. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is RS422, thermistors are connected in series on the differential lines and the signal ground line respectively. One end of a gas discharge tube is connected to each of the four differential signal lines R+, R-, T+, and T-. The other end of the gas discharge tube is connected to the signal ground line RS-GND. The signal ground line RS-GND is also connected to the nineteenth gas discharge tube. One end of a transient voltage suppression diode is connected to each of the four differential signal lines R+_1, R-_1, T+_1, and T-_1. The other end of each transient voltage suppression diode is connected to the signal ground line RS-GND_1. The signal ground line RS-GND_1 is also connected to the ninth transient voltage suppression diode. The other end of the nineteenth gas discharge tube GDT19 and the other end of the ninth transient voltage suppression diode are both connected to one end of the fourth bleeder capacitor. The other end of the fourth bleeder capacitor is grounded.

6. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is a digital input, a second varistor and a twentieth gas discharge tube are connected in series between the input terminals A and B of the digital input. Input terminals A and B are respectively connected to the two ends of one side of the coil of the second common mode inductor. The two ends of the other side of the coil of the second common mode inductor are respectively connected to the output terminals C and D. A tenth transient voltage suppressor diode is connected in parallel between the output terminals C and D. One end of the twenty-first gas discharge tube is also connected to the input terminal B, and one end of the eleventh transient voltage suppression diode is also connected to the output terminal D. The other ends of the twenty-first gas discharge tube and the eleventh transient voltage suppression diode are both connected to one end of the fifth discharge capacitor, and the other end of the fifth discharge capacitor is grounded.

7. The computer interface lightning electromagnetic pulse and dielectric strength protection device according to claim 1, characterized in that, When the interface is an analog interface, the eighteenth and nineteenth thermistors are connected in series on the two analog lines respectively. The twenty-second gas discharge tube is connected between YL and AGND. The twelfth transient voltage suppression diode is connected between YL_1 and AGND_1. One end of the twenty-third gas discharge tube is also connected to AGND. One end of the thirteenth transient voltage suppression diode is also connected to AGND_1. The other end of the thirteenth transient voltage suppression diode and the other end of the twenty-third gas discharge tube are both connected to one end of the sixth bleeder capacitor. The other end of the sixth bleeder capacitor is grounded.

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