A lightning protection filter assembly

Abstract

A lightning protection filtering component includes a shielding housing, an aviation connector, a circuit breaker, a high-frequency filter, a lightning protection circuit, a power supply filtering circuit, and a surge suppression circuit. The aviation connector serves as the product's external cross-linking interface. The circuit breaker provides overload and circuit breaker protection for the product's power supply. Signals pass through a feedthrough capacitor and a cavity partition to achieve isolation and high-frequency filtering. The lightning protection circuit, power supply filtering circuit, and surge suppression circuit are integrated onto a single circuit board. The lightning protection circuit suppresses transient overvoltages or overcurrents caused by lightning indirect effects, which can lead to damage to downstream circuits or interference with system signal transmission via cable bundle coupling. This invention integrates multiple functional modules and circuits, working together to achieve overload and circuit breaker protection, high-frequency filtering, lightning indirect effect protection, power supply filtering, and surge suppression.

Description

Technical Field

[0001] This invention relates to the field of optoelectronics, and more specifically to a lightning protection filter component for a certain airborne optoelectronic product. Background Technology

[0002] Traditional airborne optoelectronic products employ independent filter connectors, lightning protection modules, power filters, and surge suppressors to achieve high-frequency signal filtering, lightning indirect effect protection, power filtering, and surge suppression functions, respectively. This design approach occupies a large space, has complex wiring, and presents significant challenges in internal product layout and isolation. With the development of equipment technology, the requirements for product size, weight, lightning protection, electromagnetic compatibility, and power characteristics are becoming increasingly stringent. Improving the integration level of the design is a more ideal approach that addresses these various needs. Summary of the Invention

[0003] The purpose of this invention is to design a lightning protection filter component for a certain airborne optoelectronic product, which can realize functions such as overload and circuit breaker protection, high frequency filtering, lightning indirect effect protection, power supply filtering and surge suppression, so as to solve the problems of complex wiring and large space occupation in traditional technology.

[0004] The technical solution of this invention is:

[0005] A lightning protection filtering component includes a shielded housing, an aviation connector, a circuit breaker, a high-frequency filter, a lightning protection circuit, a power supply filtering circuit, and a surge suppression circuit. The shielded housing is internally configured with three shielded cavities to achieve better isolation. The aviation connector serves as the product's external interface. The circuit breaker provides overload and circuit breaker protection for the product's power supply. Signals pass through cavity partitions via feedthrough capacitors to achieve isolation and high-frequency filtering. The lightning protection circuit, power supply filtering circuit, and surge suppression circuit are integrated onto a single circuit board. The lightning protection circuit suppresses transient overvoltage or overcurrent caused by lightning indirect effects, which can lead to damage to downstream circuits or interference with system signal transmission via cable bundle coupling. The power supply filtering circuit filters the onboard power supply and controls the conducted emissions from the product's power lines. The surge suppression circuit provides overvoltage and undervoltage surge protection for the product's power supply. This invention integrates multiple functional modules and circuits, working together to achieve overload and circuit breaker protection, high-frequency filtering, lightning indirect effect protection, power supply filtering, and surge suppression.

[0006] Shielding housing: The front panel is conformally designed with the product and serves as the mounting panel for external connections; the interior is divided into three independent shielding cavities. The first cavity houses the socket and circuit breaker, the second cavity houses the lightning protection, power filtering, and surge suppression circuit board, and the third cavity houses the socket.

[0007] The high-frequency filter is a threaded feedthrough capacitor, fixed on the partition between cavities or on the cavity shell, and connected to the subsequent lightning protection circuit through a flexible printed circuit board.

[0008] The lightning protection circuit, power filtering circuit, and surge suppression circuit are designed on a single circuit board, which is mounted on the housing. Its protective ground is connected to the housing ground by a large area of ​​copper through multiple mounting holes.

[0009] Advantages of this invention: The lightning protection filter component of this invention is smaller and lighter than traditional designs; the three functional circuits of lightning protection, filtering and surge suppression are rationally arranged and work together to better meet the design requirements of photoelectric turrets in terms of lightning protection, electromagnetic compatibility and surge suppression. Attached Figure Description

[0010] Figure 1 This is a block diagram illustrating the principle of the lightning protection filter component of the present invention.

[0011] Figure 2 This is a front view of the lightning protection filter component of the present invention;

[0012] Figure 3 This is a rear view of the lightning protection filter component of the present invention;

[0013] Figure 4 This is an internal layout diagram of the lightning protection filter component of the present invention;

[0014] Figure 5 This is a circuit diagram of lightning protection, filtering, and surge suppression of the present invention;

[0015] Figure 6 This is a circuit diagram of the surge suppression circuit of the present invention.

[0016] 1 is the front panel, 2 is the U-shaped groove, 3 is the thread, 4 is the mounting surface, 5 is the aviation connector, 6 is the aviation connector, 8 is the aviation connector, 9 is the aviation connector, 10 is the connection post, 11 is the circuit breaker, 12 is the screw hole, 13 is the rear cover, 14 is the cable outlet hole, 15 is the first cavity, 18 is the circuit board, 17 is the threaded feedthrough capacitor, 19 is the threaded feedthrough capacitor, 20 is the third cavity, 21 is the second cavity, 22 is the flexible printed circuit board, and 23 is the screw hole. Detailed Implementation

[0017] like Figure 1-4 As shown, a lightning protection filter assembly includes a front panel 1, a shielding housing, a rear cover 13, and an aviation connector, a circuit breaker 11, a high-frequency filter, a lightning protection circuit, a power supply filtering circuit, and a surge suppression circuit 18, all located within the shielding housing. The front panel 1, the shielding housing, and the rear cover 13 are connected sequentially in a front-middle-rear direction.

[0018] like Figure 2and Figure 3 As shown, the front panel 1 and the shielding housing are designed as an integrated structure. The front panel 1 is externally connected to the front panel 1 of aviation connectors 5, 6, 8, and 9, circuit breaker 11, and connection post 10. The aviation connectors are the external cross-linking interfaces of the product. The mounting surface 4 of the shielding housing is designed as an L-shape, and the surface of the mounting surface 4 is treated with conductive oxidation. Screws and screw holes 12 are provided between the edge of the mounting surface 4 and the rear cover 13, and are connected by screws and screw holes 12. The mounting surface 4 of the shielding housing is designed with a U-shaped groove 2, which is used to install conductive rubber strips to achieve electromagnetic shielding and airtightness between the shielding housing and the rear cover. The circuit breaker 11 is designed with a shielding cover and is fastened with an integral thread 3. The rear cover 13 is designed with two cable outlet holes 14.

[0019] like Figure 4 As shown, the shielding housing is internally divided into three independent shielding cavities: the first cavity 15, the second cavity 21, and the third cavity 20. The first cavity 15 houses a socket and a circuit breaker 11. The second cavity 21 houses a lightning protection, power filtering, and surge suppression circuit 18 and a circuit board. The third cavity 20 houses a socket. The high-frequency filters are threaded feedthrough capacitors 17 and 19. Feedthrough capacitor 17 is fixed to the partition between the first and second cavities, with its shell well-fitted to the partition and connected to the subsequent lightning protection circuit via a flexible printed circuit board 22. Feedthrough capacitor 19 is fixed to the shell of the third cavity 20, with its shell well-fitted to the partition shell. The rear cover mounting surface 17 is designed in an L-shape, and the rear cover 13 has blind holes at positions relative to the screw holes 23, facilitating screw thread connection between the screws passing through the rear cover 13 and the screw holes 23.

[0020] The signal passes through the cavity partition via the feedthrough capacitor 17 to achieve isolation and high-frequency filtering. The lightning protection circuit, power supply filtering circuit, and surge suppression circuit 18 are integrated onto a single circuit board. The lightning protection circuit suppresses transient overvoltage or overcurrent caused by lightning indirect effects, which can lead to damage to downstream circuits or interference with system signal transmission via cable bundle coupling. The power supply filtering circuit filters the on-board power supply and controls the conducted emission of the product's power lines. The surge suppression circuit provides overvoltage and undervoltage surge protection for the product's power supply. This invention integrates multiple functional modules and circuits, working together to achieve overload and circuit breaker protection, high-frequency filtering, lightning indirect effect protection, power supply filtering, and surge suppression.

[0021] like Figure 5As shown, at the 28V power supply input port of the photoelectric turret, a bidirectional transient voltage suppressor diode V1 and a bidirectional transient voltage suppressor diode V2 are connected in series between +28V, 28VGND and the casing ground, respectively, to clamp the transient high voltage to a reasonable level (less than the maximum operating voltage of the downstream load circuit), thereby protecting the downstream load. The technical parameters of the selected TVS diodes are shown in Table 1.

[0022] Table 1

[0023]

[0024]

[0025] Power supply filtering circuit, such as Figure 5 As shown, two common-mode inductors, L1 (500μH) and L2 (2mH), are connected in series in the 28V power supply circuit, each with a rated current of 30A. Four common-mode capacitors, C2 (0.1μF), C3 (0.1μF), C4 (0.22μF), and C5 (0.22μF), are connected in series between +28V, 28VGND, and the case ground, respectively, each with a withstand voltage of 500VDC, forming a fourth-order common-mode filter circuit. Two differential-mode capacitors, C1 (0.82μF) and C6 (0.82μF), are connected in series between +28V and 28VGND, each with a withstand voltage of 750VDC. Two differential-mode inductors, L3 (80μH) and L4 (80μH), are connected in series with +28V and 28VGND, each with a rated current of 30A, forming a fourth-order differential-mode filter circuit.

[0026] like Figure 6 As shown, a surge suppression circuit is connected in series after the power supply filter circuit to achieve reverse connection protection, overvoltage surge protection, and undervoltage surge protection for the 28V power supply. The front-end MOSFET is used for surge suppression. When a surge voltage arrives, the gate voltage of this MOSFET is clamped at a high level of 12V to regulate the output voltage and limit the current flowing through the MOSFET, protecting the subsequent circuitry. The MOSFET in the main circuit of the subsequent stage is used to implement reverse connection protection and has a small on-state voltage drop. A TVS diode (transient voltage suppressor) is connected in parallel at the +28V power input terminal to clamp and limit voltage spikes within the allowable range, ensuring normal power supply operation and protecting the subsequent circuitry. This suppresses 80V, 50ms surges and ±600V, 10us spikes to within 36V, thus protecting the subsequent circuitry from damage.

Claims

1. A lightning protection filter component, characterized in that, The application relates to an aviation connector, and relates to an aviation connector with a shielding shell. The aviation connector comprises a front panel (1), a shielding shell, a rear cover (13) and aviation connectors, a circuit breaker (11), a high-frequency filter, a lightning protection circuit, a power filter circuit and a surge suppression circuit (18) which are all located in the shielding shell; the front panel (1), the shielding shell and the rear cover (13) are sequentially connected in the front-middle-rear direction; the shielding shell comprises a first cavity (15), a second cavity (21) and a third cavity (20) which are all independently shielded, wherein the first cavity (15) is internally provided with an XS1 socket and the circuit breaker (11), the second cavity (21) is internally provided with the lightning protection circuit, the power filter circuit and the surge suppression circuit (18), and the third cavity (20) is internally provided with an XS3 socket; the high-frequency filter comprises two threaded core-through capacitors, namely a first core-through capacitor (17) and a second core-through capacitor (19), which are respectively located in the first cavity (15) and the second cavity (21) and are fixed on a partition plate or the shielding shell between the first cavity (15) and the second cavity (21); the threaded core-through capacitors are connected with the lightning protection circuit through a flexible printed board (22), the lightning protection circuit, the power filter circuit and the surge suppression circuit (18) are arranged on one circuit board; signal passes through the cavity partition plate through the first core-through capacitor (17) to realize isolation and high-frequency filtering of the signal; the lightning protection circuit is used for inhibiting transient overvoltage or overcurrent caused by indirect effects of lightning to cause damage to a rear-stage circuit or interference with system signal transmission caused by cable bundle coupling; the power filter circuit is used for filtering and processing power supply on an airplane and controlling power line transmission of the product; the surge suppression circuit is used for realizing overvoltage surge and under-voltage surge protection of product power supply. A front-stage MOS tube of the surge suppression circuit is used for surge suppression; when surge voltage comes, a MOS gate voltage is clamped at a high 12V level to regulate output voltage and limit current flowing through the front-stage MOS tube, thereby protecting a rear-stage circuit; a rear-stage MOS tube is used for realizing reverse connection protection of the circuit, and has a small conduction voltage drop; a TVS tube is connected in parallel with a +28V power input end in a mode, voltage peaks are limited in an allowed range in a clamping mode, normal work of the power supply is ensured, and protection of a rear-end circuit is realized.

2. The lightning protection filter assembly of claim 1, wherein, An installation surface of the shielding shell is L-shaped, and a surface of the shielding shell is provided with a conductive oxide layer.

3. The lightning protection filter assembly of claim 1, wherein, A U-shaped groove (2) is arranged on the installation surface of the shielding shell, and a conductive rubber strip for realizing electromagnetic shielding and sealing the shielding shell and the rear cover (13) is arranged in the U-shaped groove (2).

4. The lightning protection filter assembly of claim 1, wherein, The rear cover (13) comprises a wire outlet (14).

5. The lightning protection filter assembly of claim 1, wherein, The aviation connector is arranged on the front panel (1).

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