High-stability lightning protection data acquisition device

Abstract

The utility model discloses a high-stability lightning protection data acquisition device comprising a main control chip which receives data of an air pressure sensor, a wind speed sensor and a wind direction sensor through an RS485 interface, and receives data of a temperature and humidity sensor and GNSS data acquired by a GNSS acquisition module in real time through an SCI interface. The received GNSS data are uploaded to an upper computer through the first CAN bus interface, and the collected air pressure, wind speed, wind direction and temperature and humidity data are uploaded to the upper computer through the second CAN bus interface. According to the data acquisition device disclosed by the utility model, the lightning protection circuits are arranged among the RS485 interface, the first CAN bus interface, the second CAN bus interface, the SCI interface, the power input interface and the rear-end circuit, so that the data acquisition device can be effectively prevented from being damaged by lightning strokes, and a large amount of manpower and material resource cost for subsequent maintenance is saved.

Description

Technical Field

[0001] This utility model relates to the field of data acquisition, and more specifically to a lightning protection data acquisition device in this field. Background Technology

[0002] Existing data acquisition devices have two main problems: First, they lack effective lightning protection design, making them susceptible to damage from lightning strikes during the rainy season; second, the power supply design is insufficient, and when all circuits work together, the power chip operates at full load, resulting in very high device temperatures. Over long-term operation, the performance of the circuit board degrades rapidly and it is easily damaged. Utility Model Content

[0003] To address the technical problems of existing data acquisition devices lacking effective lightning protection design, insufficient power supply, and high operating temperature, this utility model provides a highly stable lightning-proof data acquisition device that can both protect against lightning strikes and solve the problem of power supply overheating.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] An improved high-stability lightning protection data acquisition device includes a main control chip. The main control chip receives data from a barometric pressure sensor and wind speed and direction sensor via an RS485 interface, receives data from a temperature and humidity sensor and GNSS data collected in real time by a GNSS acquisition module via an SCI interface, uploads the received GNSS data to a host computer via a first CAN bus interface, and uploads the acquired barometric pressure, wind speed, wind direction, and temperature and humidity data to the host computer via a second CAN bus interface.

[0006] Furthermore, the main control chip selected is the TMS320F28335; the TMS320F28335 reads data from the barometric pressure sensor, wind speed and direction sensor, completing the data acquisition functions for barometric pressure, wind speed and direction; the TMS320F28335 reads data from the temperature and humidity sensor, completing the temperature and humidity data acquisition function; the TMS320F28335 reads data from the GNSS acquisition module, completing the GNSS data acquisition function; the TMS320F28335 transmits all collected meteorological data through the second CAN bus interface. The meteorological data uploaded to the host computer includes air pressure, wind speed, wind direction, temperature, and humidity data. The TMS320F28335 processes the collected meteorological data and uploads it to the host computer according to the data format and protocol specified by the host computer. The TMS320F28335 also uploads the received GNSS data to the host computer through the first CAN bus interface.

[0007] Furthermore, the barometric pressure sensor collects barometric pressure data in real time. The barometric pressure sensor is powered by +5V and has an RS485 interface, which is connected to the J5 interface of the high-stability lightning-proof data acquisition device. The wind speed and direction sensors collect wind speed and direction data in real time. The wind speed and direction sensors are powered by +24V and have RS485 interfaces, which are connected to the J3 interface of the high-stability lightning-proof data acquisition device. The two RS485 interfaces of J3 and J5 are connected in parallel to the 485 terminal of the 485 interface chip MAX3485. The UART terminal of MAX3485 is connected to the SCIA of TMS320F28335.

[0008] Furthermore, the temperature and humidity sensor collects temperature and humidity data in real time. The temperature and humidity sensor is powered by +3.3V and has an SCI interface. It is connected to the J3 interface of the high-stability lightning protection data acquisition device. The J3 interface is connected to the SCIB of the TMS320F28335.

[0009] Furthermore, the GNSS acquisition module collects GNSS data in real time. The GNSS acquisition module is powered by +5V, has a COM2 interface, and is connected to the J9 interface of the high-stability lightning-proof data acquisition device. The J9 interface is connected to the SCIC of the TMS320F28335.

[0010] Furthermore, surge protection circuits are installed between the RS485 interface, the first and second CAN bus interfaces, the SCI interface, the power input interface, and the back-end circuit. The power supply circuit adopts a distributed parallel design. The surge protection circuit of the RS485 interface includes a ceramic gas discharge tube, two resettable fuses, and an electrostatic discharge protection diode. The interface 2 of the ceramic gas discharge tube is grounded, and interfaces 1 and 3 are connected between the input terminal of the RS485 interface and the back-end circuit, respectively. The interface 2 of the electrostatic discharge protection diode is grounded, and interfaces 1 and 3 are connected between interfaces 1 and 3 of the ceramic gas discharge tube and the back-end circuit, respectively. One resettable fuse is connected between interface 1 of the electrostatic discharge protection diode and interface 1 of the ceramic gas discharge tube, and the other resettable fuse is connected between interface 3 of the electrostatic discharge protection diode and interface 3 of the ceramic gas discharge tube.

[0011] Furthermore, the surge protection circuits for both the first and second CAN bus interfaces include two resettable fuses and a TVS diode array. Interface 2 of the TVS diode array is grounded, and interfaces 1 and 3 are respectively connected between the input terminal of the CAN bus interface and the back-end circuit. One resettable fuse is connected between interface 1 of the TVS diode array and the input terminal of the CAN bus interface, and the other resettable fuse is connected between interface 3 of the TVS diode array and the input terminal of the CAN bus interface.

[0012] Furthermore, the surge protection circuit for the SCI interface includes ESD diodes and ESD electrostatic protection devices.

[0013] Furthermore, the surge protection circuit of the power input interface includes a rectifier diode, a ceramic gas discharge tube, and a resettable fuse. The rectifier diode is electrically connected to the resettable fuse, the resettable fuse is electrically connected to the 24V power input terminal, the ceramic gas discharge tube's interface 2 is grounded, and interface 1 is electrically connected to the resettable fuse.

[0014] Furthermore, the power supply circuit uses three independent power conversion chips with a distributed parallel power supply design, and the outputs are 5V, 3.3V and 1.9V respectively.

[0015] The beneficial effects of this utility model are:

[0016] The data acquisition device disclosed in this utility model is equipped with lightning protection circuits between the RS485 interface, the first and second CAN bus interfaces, the SCI interface, the power input interface and the back-end circuit, which can effectively avoid damage from lightning strikes and save a lot of manpower and material costs for subsequent maintenance.

[0017] The data acquisition device disclosed in this utility model has a new power supply circuit designed to address the problem of insufficient power supply. It adopts a distributed parallel design instead of the original series design, changing the power supply current from a single narrow current to multiple broad currents. This solves the problems of heat generation and performance degradation caused by insufficient power supply, improves the stability and reliability of the device, and enables it to work stably for a long time without damage. Attached Figure Description

[0018] Figure 1 This is a circuit design block diagram of the data acquisition device disclosed in this utility model;

[0019] Figure 2 This is a circuit connection diagram of the barometric pressure sensor and the wind speed and direction sensor;

[0020] Figure 3 This is a circuit connection diagram of a temperature and humidity sensor;

[0021] Figure 4 This is a circuit connection diagram of the GNSS acquisition module;

[0022] Figure 5 This is a circuit diagram showing the connection between the CANB interface of the TMS320F28335 and the host computer.

[0023] Figure 6 This is a circuit diagram showing the connection between the CANA interface of the TMS320F28335 and the host computer.

[0024] Figure 7 This is a schematic diagram of the surge protection circuit for the RS485 interface in the data acquisition device disclosed in this utility model;

[0025] Figure 8-1 is a schematic diagram of the lightning protection circuit of the first CAN bus interface in the data acquisition device disclosed in this utility model;

[0026] Figure 8-2 is a schematic diagram of the lightning protection circuit of the second CAN bus interface in the data acquisition device disclosed in this utility model;

[0027] Figure 9 This is a schematic diagram of the surge protection circuit for the SCI interface in the data acquisition device disclosed in this utility model;

[0028] Figure 10 This is a schematic diagram of the surge protection circuit for the power input interface in the data acquisition device disclosed in this utility model;

[0029] Figure 11-1 is a schematic diagram of the 5V power supply circuit in the data acquisition device disclosed in this utility model;

[0030] Figure 11-2 is a schematic diagram of the 3.3V power supply circuit in the data acquisition device disclosed in this utility model;

[0031] Figure 11-3 is a schematic diagram of the 1.9V power supply circuit in the data acquisition device disclosed in this utility model;

[0032] Figure 12 This is a comparison chart of the power supply current for series and distributed parallel connections. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0034] Example 1, such as Figure 1 As shown, this embodiment discloses a highly stable lightning protection data acquisition device, using a TMS320F28335 as the main control chip. The main control chip receives data from a barometric pressure sensor and a wind speed and direction sensor via an RS485 interface, receives data from a temperature and humidity sensor and GNSS data collected in real time by a GNSS acquisition module via an SCI interface, uploads the received GNSS data to a host computer via a first CAN bus interface, and uploads the collected barometric pressure, wind speed, wind direction, and temperature and humidity data to a host computer via a second CAN bus interface.

[0035] The TMS320F28335 is a high-performance 32-bit floating-point DSP processor from TI's TMS320C28X series. It combines the features of a microcontroller and a high-performance DSP, possessing powerful control and signal processing capabilities, enabling the implementation of complex control algorithms. On-chip peripherals include Flash memory, a fast A / D converter, an enhanced CAN module, an event manager, an orthogonal encoder interface, and a multi-channel buffered serial port.

[0036] The main features of the TMS320F28335 are its high-speed computing power, fast interrupt response speed and data processing capabilities, and efficient programming methods.

[0037] The main resources of the TMS320F28335 processor are as follows:

[0038] It integrates the strengths of DSPs and microcontrollers, including key features of DSPs such as single-cycle multiplication. It features six sets of complementary symmetrical pulse width modulation (PWM) units, each containing two PWM channels: PWMxA and PWMxB. It has six enhanced capture units (CAPs). It also has two enhanced quadrature encoding units (QEPs). There is one 12-bit A / D converter. It has three SCI asynchronous serial ports, commonly known as UARTs. There are two enhanced CAN bus controllers compliant with the CAN 2.0B protocol. It has one SPI interface. There is one FC synchronous serial port. The external memory interface includes 20 address lines, 16 (maximum 32) data lines, three chip select control lines, and read / write control lines. It has a total of 88 general-purpose input / output (GPIO) ports. It also features a 6-channel DMA processor, significantly improving the efficiency of large-scale data transfers.

[0039] A barometric pressure sensor collects barometric pressure data in real time. The barometric pressure sensor is powered by +5V and has an RS485 interface, connected to the J5 interface of a high-stability, lightning-protected data acquisition device. Wind speed and direction sensors collect wind speed and direction data in real time. The wind speed and direction sensors are powered by +24V and have RS485 interfaces, connected to the J3 interface of the high-stability, lightning-protected data acquisition device. The two RS485 interfaces (J3 and J5) are connected in parallel to the 485 pin of the MAX3485 485 interface chip. The UART pin of the MAX3485 is connected to the SCIA pin of the TMS320F28335. The circuit connection diagram is shown below. Figure 2 As shown.

[0040] The TMS320F28335 is used to debug embedded programs, read data from barometric pressure sensors, and wind speed and direction sensors to complete the data acquisition functions for barometric pressure, wind speed, and wind direction.

[0041] The temperature and humidity sensor collects temperature and humidity data in real time. The sensor is powered by +3.3V and uses an SCI interface, which connects to the J3 interface of a high-stability, lightning-protected data acquisition device. The J3 interface connects to the SCIB of the TMS320F28335. The circuit connection diagram is shown below. Figure 3 As shown.

[0042] Debug the embedded program using TMS320F28335 to read temperature and humidity sensor data and complete the temperature and humidity data acquisition function.

[0043] The GNSS acquisition module collects GNSS data in real time. The GNSS acquisition module is powered by +5V and has a COM2 interface, which connects to the J9 interface of a high-stability, lightning-protected data acquisition device. The J9 interface connects to the SCIC of the TMS320F28335. The circuit connection diagram is shown below. Figure 4 As shown.

[0044] The TMS320F28335 is used to debug embedded programs, read data from the GNSS acquisition module, and complete the GNSS data acquisition function.

[0045] The TMS320F28335 uploads all collected meteorological data (including air pressure, wind speed, wind direction, temperature, and humidity data) to the host computer via the CANB interface (second CAN bus interface). A circuit connection diagram between the TMS320F28335 CANB interface and the host computer is shown below. Figure 5 As shown.

[0046] The TMS320F28335 is used to debug embedded programs, process the collected meteorological data, and upload the meteorological data to the host computer according to the data format and protocol specified by the host computer.

[0047] The TMS320F28335 uploads received GNSS data to the host computer via the CANA interface (first CAN bus interface). A circuit connection diagram of the TMS320F28335 CANA interface and the host computer is shown below. Figure 6 As shown.

[0048] The TMS320F28335 debugs embedded programs, processes the collected GNSS data, and uploads the GNSS data to the host computer according to the data format and protocol specified by the host computer.

[0049] Lightning protection circuits are installed between the RS485 interface, the first and second CAN bus interfaces, the SCI interface, the power input interface and the back-end circuit of the acquisition device, and the power supply circuit adopts a distributed parallel design.

[0050] RS485 communication uses differential signal transmission, half-duplex mode, daisy-chain connection, and cannot be multi-stage parallelized. The maximum transmission distance is 1200 meters, with a maximum of 32 nodes. It uses two data lines and one ground line. Data transmission uses a no-acknowledgment mechanism. Positive voltage is +2V to +6V, and negative voltage is -1V to -6V.

[0051] The RS485 bus boasts excellent anti-interference capabilities, long-distance transmission, and multi-node capability, making it a preferred serial interface widely used in industrial environments. While capable of long-distance transmission exceeding 1200 meters, RS485 lines are typically outdoors, making them susceptible to overvoltage from lightning strikes during thunderstorms. Inadequate protection can easily damage chips. Furthermore, electrostatic discharge (ESD) and electromagnetic interference severely impact the data transmission quality of the RS485 communication bus. Because RS485 transceivers operate at relatively low voltages (around 5V) and have very low withstand voltage (-7V to +12V), they are easily damaged by overvoltage.

[0052] The data acquisition device in this embodiment is designed with three RS485 bus interfaces. The first RS485 bus is connected to the barometric pressure sensor to read the barometric pressure sensor data; the second RS485 bus is connected to the wind speed and wind direction sensor to read the wind speed and wind direction sensor data; and the third RS485 bus is a reserved interface.

[0053] like Figure 7 As shown, the surge protection circuit for the RS485 interface includes a ceramic gas discharge tube 21, two resettable fuses 22, and an electrostatic discharge protection diode 23. The ceramic gas discharge tube's interface 2 is grounded, and interfaces 1 and 3 are connected between the input terminal of the RS485 interface and the back-end circuit, respectively. The electrostatic discharge protection diode's interface 2 is grounded, and interfaces 1 and 3 are connected between the ceramic gas discharge tube's interfaces 1 and 3 and the back-end circuit, respectively. One resettable fuse is connected between the electrostatic discharge protection diode's interface 1 and the ceramic gas discharge tube's interface 1, and the other resettable fuse is connected between the electrostatic discharge protection diode's interface 3 and the ceramic gas discharge tube's interface 3.

[0054] Specifically, for primary protection of the RS485 bus, a three-terminal GDT ceramic gas discharge tube 3R90A-TP1 is used for surge overvoltage protection, and a self-resetting fuse DW-MSM050 is used for overcurrent protection. Secondary protection uses an SM712 (45pF junction capacitance), an ESD protection diode specifically designed for RS-485 communication transmission interface protection (-7V, 12V), whose 45pF junction capacitance ensures signal integrity. The ceramic gas discharge tube discharges surge current to ground or eliminates it as heat in the inert gas arc within the tube's electrodes. The ceramic gas discharge tube provides full common-mode and differential-mode protection and is suitable for fully exposed direct lightning strike areas.

[0055] The above surge protection circuit provides the RS485 interface with good surge protection capability, capable of protecting against induced lightning strikes below 4kV. This achieves protection for the RS485 circuit.

[0056] The CAN bus interface adopts a decentralized node design, enabling multi-node control. Its communication speed is higher than RS485, with a maximum communication distance of 500 meters. A standard CAN frame transmits one byte (8 bits) of data at a time, while an extended frame transmits 8 bytes at a time. It features an ACK (acknowledgment) mechanism, with a bus high voltage of 2.5V~3.5V and a bus low voltage of 1.5V~2.5V.

[0057] The data acquisition device in this embodiment is designed with two CAN bus interfaces. The first CAN bus is connected to the host computer to upload the acquired GNSS data; the second CAN bus is connected to the host computer to receive commands from the host computer and perform information exchange, while uploading the acquired data from sensors such as air pressure, temperature and humidity, wind speed, and wind direction.

[0058] like Figure 8-1 As shown in Figure 8-2, the surge protection circuits for the first and second CAN bus interfaces each include two resettable fuses 31 and a TVS diode array 32. The interface 2 of the TVS diode array is grounded, and interfaces 1 and 3 are respectively connected between the input terminal of the CAN bus interface and the back-end circuit. One resettable fuse is connected between interface 1 of the TVS diode array and the input terminal of the CAN bus interface, and the other resettable fuse is connected between interface 3 of the TVS diode array and the input terminal of the CAN bus interface.

[0059] The 25pF parasitic capacitance of the TVS diode array HDW24M2T-B will not affect FD communication on the CAN bus, and its breakdown voltage is 26.7V. A resettable fuse DW-MSM014 provides overcurrent protection.

[0060] SCI interfaces are primarily used for communication between computers and devices, for data monitoring and debugging. During application, they are frequently hot-plugged (e.g., with USB-to-serial devices), causing electrostatic surges. Simultaneously, communication cables are susceptible to external interference, affecting signal transmission. These factors can easily damage the communication interface chip within the board. Therefore, it is necessary to protect the TTL interface circuitry of SCI transmission to ensure the safe operation of the onboard MCU and SCI communication chip.

[0061] The data acquisition device in this embodiment is designed with one SCI bus interface. The SCI bus is connected to the temperature and humidity sensor, providing power to the sensor and acquiring its data. Figure 9As shown, the surge protection circuit for the SCI interface includes an ESD diode 41 and an ESD electrostatic discharge (ESD) protection device 42. For power supply surge protection, the SD05C ESD diode is selected, with a maximum surge current peak of 30A and low clamping voltage characteristics, ensuring the MCU operates within a safe voltage range. For ESD protection of the transmission signal lines, the DW05DLC-BS ESD protection device is selected, with an operating voltage of 5V and a junction capacitance as low as 1pF, ensuring high-speed signal transmission between the MCU and the interface chip.

[0062] The data acquisition device in this embodiment uses a 24V input power supply. The power input passes through a 1N4004 rectifier diode, which has a maximum reverse withstand voltage of 400V, providing reverse voltage protection. A three-terminal GDT ceramic gas discharge tube (3R90A-TP1) is used for surge overvoltage protection, and a resettable fuse (PPTC-DW-Msmd200-24) is used for overcurrent protection. The ceramic gas discharge tube discharges the surge current to ground or eliminates it as heat through an inert gas electro-optical arc within the electrodes. Figure 10 As shown, rectifier diode 51 is electrically connected to resettable fuse 52, resettable fuse is electrically connected to 24V power input terminal, interface 2 of ceramic gas discharge tube 53 is grounded, and interface 1 is electrically connected to resettable fuse.

[0063] The above surge protection circuit design provides excellent surge protection for the power input interface, preventing induced lightning strikes up to 4kV. This effectively protects the power input interface circuit.

[0064] The 24V power supply enters the data acquisition device through the power input interface to power the power supply circuit, such as... Figure 11-1 As shown in Figures 11-2 and 11-3, the power supply circuit uses three independent power conversion chips with outputs of 5V, 3.3V and 1.9V respectively.

[0065] The existing data acquisition device suffers from overheating during operation, primarily due to insufficient power supply from the power circuit. The circuit design uses a series power supply design, employing the TL2575-05IKTTR as the primary power conversion chip. This chip supports a wide input voltage range of 4.75V to 40V and outputs at 5V, with a maximum output power consumption of 5W. The power supply chips TPS75733 and TPS76801 are powered by this 5V supply. This 5W power consumption is divided into three parts: the 5V power supply circuit, the TPS75733 and subsequent 3.3V power supply circuits, and the TPS76801 and subsequent 1.9V power supply circuits. In actual operation, the 5W supply is insufficient to meet the total power consumption requirements of these three circuits, resulting in overload and overheating of the power module.

[0066] In this embodiment, the power supply circuit of the data acquisition device uses a distributed parallel design instead of the original series design. Three TPS5430 power inputs are selected, with a wide voltage range of 10V~35V, and outputs of 5V / 3A, 3.3V / 3A, and 1.9V / 3A respectively. In actual operation, the maximum output power consumption at 5V, 3.3V, and 1.9V reaches 15W, 9.9W, and 5.7W respectively, fully meeting the power consumption requirements of each channel. The total power consumption is 15 + 9.9 + 5.7 = 30.6W, far exceeding 5W.

[0067] By changing the series connection to a distributed parallel connection, the current is transformed from a single narrow current into multiple broad currents, solving problems such as overheating caused by insufficient power supply. Figure 12 The diagram on the left shows the power supply current of the existing data acquisition device. Figure 12 The diagram on the right shows the power supply current of the data acquisition device in this embodiment.

Claims

1. A highly stable lightning-proof data acquisition device, characterized in that: The main control chip receives the air pressure sensor and wind speed, wind direction sensor data through the RS485 interface, receives the temperature and humidity sensor data and GNSS data collected by the GNSS acquisition module in real time through the SCI interface, uploads the received GNSS data to the upper computer through the first CAN bus interface, and uploads the collected air pressure, wind speed, wind direction and temperature and humidity data to the upper computer through the second CAN bus interface.

2. The high-stability lightning-protection data acquisition device according to claim 1, characterized in that: The main control chip selects TMS320F28335; TMS320F28335 reads the air pressure sensor data, wind speed, wind direction sensor data, completes the air pressure data, wind speed, wind direction data acquisition function; TMS320F28335 reads the temperature and humidity sensor data, completes the temperature and humidity data acquisition function; TMS320F28335 reads the GNSS acquisition module data, completes the GNSS data acquisition function; TMS320F28335 uploads all the meteorological data collected to the upper computer through the second CAN bus interface, and the meteorological data includes air pressure, wind speed, wind direction, temperature and humidity data; TMS320F28335 processes the collected meteorological data, uploads the meteorological data to the upper computer according to the data format and protocol specified by the upper computer; TMS320F28335 uploads the received GNSS data to the upper computer through the first CAN bus interface, and TMS320F28335 processes the collected GNSS data, uploads the GNSS data to the upper computer according to the data format and protocol specified by the upper computer.

3. The high-stability lightning-protection data acquisition device according to claim 2, characterized in that: The air pressure sensor collects air pressure data in real time, the air pressure sensor is powered by +5V, the RS485 interface is connected to the J5 interface of the high-stability lightning-proof data acquisition device, the wind speed, wind direction sensor collects wind speed, wind direction data in real time, the wind speed, wind direction sensor is powered by +24V, the RS485 interface is connected to the J3 interface of the high-stability lightning-proof data acquisition device, and the two-way RS485 of J3 and J5 is connected to the 485 end of the 485 interface chip MAX3485, and the UART end of MAX3485 is connected to the SCIA of TMS320F28335.

4. The high-stability lightning-protection data acquisition device according to claim 2, characterized in that: The temperature and humidity sensor collects temperature and humidity data in real time, the temperature and humidity sensor is powered by +3.3V, the SCI interface is connected to the J3 interface of the high-stability lightning-proof data acquisition device, and the J3 interface is connected to the SCIB of TMS320F28335.

5. The high-stability lightning-protection data acquisition device according to claim 2, characterized in that: The GNSS acquisition module collects GNSS data in real time, the GNSS acquisition module is powered by +5V, the COM2 interface is connected to the J9 interface of the high-stability lightning-proof data acquisition device, and the J9 interface is connected to the SCIC of TMS320F28335.

6. The high-stability lightning-protection data acquisition device according to claim 1, characterized in that: Lightning protection circuit is arranged between RS485 interface, first and second CAN bus interface, SCI interface, power input interface and rear-end circuit, and power supply circuit adopts distributed parallel design; the lightning protection circuit of the RS485 interface comprises a ceramic gas discharge tube, two self-recovery fuses and an electrostatic protection diode, wherein the interface 2 of the ceramic gas discharge tube is grounded, the interfaces 1 and 3 are respectively connected between the input end of the RS485 interface and the rear-end circuit, the interface 2 of the electrostatic protection diode is grounded, the interfaces 1 and 3 are respectively connected between the interfaces 1 and 3 of the ceramic gas discharge tube and the rear-end circuit, one self-recovery fuse is connected between the interface 1 of the electrostatic protection diode and the interface 1 of the ceramic gas discharge tube, and the other self-recovery fuse is connected between the interface 3 of the electrostatic protection diode and the interface 3 of the ceramic gas discharge tube.

7. The high-stability lightning-protection data acquisition device according to claim 6, characterized in that: The lightning protection circuit of the first and second CAN bus interface each comprises two self-recovery fuses and a TVS diode array, the interface 2 of the TVS diode array is grounded, the interfaces 1 and 3 are respectively connected between the input end of the CAN bus interface and the rear-end circuit, one self-recovery fuse is connected between the interface 1 of the TVS diode array and the input end of the CAN bus interface, and the other self-recovery fuse is connected between the interface 3 of the TVS diode array and the input end of the CAN bus interface.

8. The high-stability lightning-protection data acquisition device according to claim 6, characterized in that: The lightning protection circuit of the SCI interface comprises an ESD diode and an ESD electrostatic protection device.

9. The high-stability lightning-protection data acquisition device according to claim 6, characterized in that: The lightning protection circuit of the power input interface comprises a rectifier diode, a ceramic gas discharge tube and a self-recovery fuse, the rectifier diode is electrically connected with the self-recovery fuse, the self-recovery fuse is electrically connected with the 24V power input end, the interface 2 of the ceramic gas discharge tube is grounded, and the interface 1 is electrically connected with the self-recovery fuse.

10. The high-stability lightning-protection data acquisition device of claim 6, wherein: The power supply circuit adopts three independent power conversion chips, and uses distributed parallel power supply design, and the outputs are 5V, 3.3V and 1.9V respectively.

Images