A multi-stage voltage-dependent resistor and gas discharge tube based on-board lightning protection circuit

Abstract

The utility model discloses a kind of board-mounted lightning protection circuit based on multistage pressure-sensitive resistance and gas discharge tube, comprising: multistage protection circuit, consisting of 21 independent protection units, each protection unit contains pressure-sensitive resistance and gas discharge tube parallel structure, each protection unit is arranged in series on PCB board;Monitoring control circuit, connect 6-way state indicating lamp LED1-LED6, buzzer alarm module FMQ, 3 physical buttons S1-S3 and temperature sensor WD1;Communication interface, connect RS485 module and relay output JDQ;Power module, for providing 5V and 3.3V power supply.The utility model is realized nanosecond level surge response by 21 levels of protection unit, simultaneously adopt board-mounted integration and make volume reduce more than 60%, the utility model real-time monitoring each protection unit state and feedback by multiple ways.

Description

Technical Field

[0001] This utility model relates to the field of circuit protection technology, and more specifically, to an onboard lightning protection circuit based on multi-stage varistors and gas discharge tubes. Background Technology

[0002] Currently, traditional lightning protection devices mostly use discrete components, which suffer from slow response speed, low integration, and lack of status monitoring. Therefore, it is necessary to solve these shortcomings by integrating multi-level protection units and intelligent monitoring modules through PCBs. Utility Model Content

[0003] The purpose of this invention is to provide an onboard surge protection circuit based on multi-stage varistors and gas discharge tubes to overcome the defects of the existing technology.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] An onboard surge protection circuit based on multi-stage varistors and gas discharge tubes includes:

[0006] The multi-level protection circuit consists of 21 independent protection units. Each protection unit includes a parallel structure of a varistor and a gas discharge tube. The protection units are arranged in series on the PCB board.

[0007] The monitoring and control circuit connects to 6 status indicator lights (LED1-LED6), a buzzer alarm module (FMQ), 3 physical buttons (S1-S3), and a temperature sensor (WD1).

[0008] Communication interface, connecting RS485 module and relay output JDQ;

[0009] Power supply module, used to provide 5V and 3.3V power.

[0010] Furthermore, the monitoring and control circuit includes an STM32F chip, a clock chip U7, and a temperature-compensated crystal oscillator X2. The clock chip U7 and the temperature-compensated crystal oscillator X2 are connected via I... 2 The C bus connects to the STM32F chip.

[0011] Furthermore, the RS485 module uses the SP3485 chip U5, the enable terminal DRE of the SP3485 chip U5 is connected to the STM32F chip, and the differential signal lines 485+ / 485- are protected by TVS diodes D9-D13.

[0012] Furthermore, the power module includes a chip U3 with model number HLK-5M05 and a chip U4 with model number AMS1117-3.3. The AC input is converted to 5V by chip U3, and then generated to 3.3V by U4 for use by the STM32F chip.

[0013] Furthermore, the power module input terminal is equipped with a common mode choke L1-1 and a varistor R31, and gas discharge tubes F1-F2 are connected in parallel between the AC line and the PE ground.

[0014] Compared with the prior art, the advantages of this utility model are: this utility model achieves nanosecond-level surge response through 21-level protection units, and at the same time, it adopts on-board integration to reduce the volume by more than 60%. This utility model monitors the status of each protection unit in real time and provides feedback through multiple methods. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the present invention;

[0017] Figure 2 This is a circuit diagram of the multi-level protection circuit in this utility model;

[0018] Figure 3 This is a circuit diagram of the monitoring and control circuit in this utility model;

[0019] Figure 4 This is the circuit diagram of the 6-channel status indicator lights in this utility model;

[0020] Figure 5 This is the circuit diagram of the buzzer alarm module in this utility model;

[0021] Figure 6 This is the circuit diagram of the three physical buttons in this utility model;

[0022] Figure 7 This is the circuit diagram of the temperature sensor WD1 in this utility model;

[0023] Figure 8 This is the circuit diagram of the RS485 module in this utility model;

[0024] Figure 9 This is the circuit diagram of the relay output JDQ in this utility model;

[0025] Figure 10 This is the circuit diagram of the power supply module in this utility model. Detailed Implementation

[0026] The following detailed description of further embodiments of the present invention, in conjunction with the accompanying drawings, will make the advantages and features of the present invention more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0027] See Figure 1-10 As shown, this utility model provides an onboard surge protection circuit based on multi-stage varistors and gas discharge tubes, comprising:

[0028] The multi-level protection circuit consists of 21 independent protection units. Each protection unit includes a parallel structure of a varistor and a gas discharge tube. The protection units are arranged in series on the PCB board.

[0029] The monitoring and control circuit connects to 6 status indicator lights (LED1-LED6), a buzzer alarm module (FMQ), 3 physical buttons (S1-S3), and a temperature sensor (WD1).

[0030] Communication interface, connecting RS485 module and relay output JDQ;

[0031] Power supply module, used to provide 5V and 3.3V power.

[0032] In this embodiment, the ZD100-600 type varistor (such as the ZD100-600 of the first protection unit) in the multi-level protection circuit is connected in parallel between the input terminals (P0100 and P0103) to clamp overvoltage; the two poles of the gas discharge tube are respectively shorted to the two ends of the varistor (such as P0101-P0102 shorting one pole of the discharge tube, and P0103-P0100 shorting the other pole).

[0033] After a lightning surge is input through the CN1 terminal, it passes through 21 protection units in sequence. The low-voltage section (pre-stage unit such as `ZD100-600` in `1`) provides a fast response (nanosecond level) to absorb low-energy surges, while the high-voltage section (post-stage unit such as `ZD100-230` in `20`) handles the remaining high-energy impact. Varistors are used to suppress transient overvoltages, and the gas discharge tube conducts during sustained overvoltage to prevent the varistor from overheating and failing.

[0034] In this embodiment, the monitoring and control circuit includes an STM32F chip, a clock chip U7, and a temperature-compensated crystal oscillator X2. The clock chip U7 and the temperature-compensated crystal oscillator X2 are connected via I... 2 The C-bus connects to the STM32F chip, which integrates acquisition, control, and communication functions in a 64-pin package.

[0035] In this embodiment, the six status indicator lights LED1-LED6 are driven by transistors (Q2-Q7) and controlled by PA0-PA7 to display the health status of the protection unit.

[0036] In this embodiment, the buzzer alarm module FMQ is driven by transistor Q1, and the PB0 pin of the STM32F chip controls the over-limit alarm.

[0037] In this embodiment, the temperature sensor WD1 is directly connected to the PC3 pin of the STM32F chip to monitor the ambient temperature.

[0038] In this embodiment, the three physical buttons S1-S3 are debounced by an RC circuit (R25-R27 / C12-C14) and then input to the PC0-PC2 pins of the STM32F chip.

[0039] In this embodiment, the real-time clock chip U7 (AT24C16C) stores parameters, and the temperature-compensated crystal oscillator X2 (8MHz) ensures timing accuracy.

[0040] In this embodiment, the RS485 module uses the SP3485 chip U5. The enable terminal DRE of the SP3485 chip is connected to the STM32F chip, and the differential signal lines 485+ / 485- are protected by TVS diodes D9-D13.

[0041] The isolation control of the RS485 module is as follows: the enable signal DRE (P0CN1012) is controlled by pin PB11 of the SP3485 chip and is isolated by an optocoupler; the bus protection is as follows: the differential lines 485+ / 485- (P0CN1010-P0CN1011) are connected in parallel with TVS diodes D9-D13 (e.g., D13: 6.8CA) to suppress surges; the impedance matching is as follows: resistors R33 / R39 (4.7kΩ) to ensure signal integrity.

[0042] In this embodiment, the relay output JDQ is driven by Q8 (S8050) and controlled by the PC8 pin of the SP3485 chip for remote fault linkage.

[0043] In this embodiment, the power module includes a chip U3 with model number HLK-5M05 and a chip U4 with model number AMS1117-3.3. The AC input is converted to 5V by chip U3, and then generated to 3.3V by U4 for use by the STM32F chip.

[0044] The power module input terminal is equipped with a common mode choke L1-1 and a varistor R31, and gas discharge tubes F1-F2 are connected in parallel between the AC line and the PE ground.

[0045] AC input filtering uses common-mode inductor L1-1 to suppress high-frequency interference, varistor R31 (10D471K) to absorb mains surges, and gas discharge tubes F1 / F2 (JK250) to bridge L / N and PE; DC conversion uses U3 (HLK-5M05) to output 5V AC / DC and U4 (AMS1117-3.3) to step down to 3.3V for the MCU; EMC protection uses multi-layer filter capacitors (C15 / C16 / C17) at the input / output terminals and TVS diode D1 (M7-SMA) to protect the 3.3V power supply.

[0046] This invention achieves nanosecond-level surge response through 21-level protection units, while adopting onboard integration to reduce the volume by more than 60%. This invention monitors the status of each protection unit in real time and provides feedback through multiple methods.

[0047] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, the patent owner may make various modifications or alterations within the scope of the appended claims, as long as they do not exceed the protection scope described in the claims of the present invention, they shall all be within the protection scope of the present invention.

Claims

1. A plate-mounted surge protection circuit based on multi-stage varistors and gas discharge tubes, characterized in that, include: The multi-level protection circuit consists of 21 independent protection units. Each protection unit includes a parallel structure of a varistor and a gas discharge tube. The protection units are arranged in series on the PCB board. The monitoring and control circuit connects to 6 status indicator lights (LED1-LED6), a buzzer alarm module (FMQ), 3 physical buttons (S1-S3), and a temperature sensor (WD1). Communication interface, connecting RS485 module and relay output JDQ; Power supply module, used to provide 5V and 3.3V power.

2. The on-board surge protection circuit based on multi-stage varistors and gas discharge tubes according to claim 1, characterized in that, The monitoring and control circuit includes an STM32F chip, a clock chip U7, and a temperature-compensated crystal oscillator X2. The clock chip U7 and the temperature-compensated crystal oscillator X2 are connected via I... 2 The C bus connects to the STM32F chip.

3. The on-board surge protection circuit based on multi-stage varistors and gas discharge tubes according to claim 1, characterized in that, The RS485 module uses SP3485 chip U5. The enable terminal DRE of SP3485 chip U5 is connected to the STM32F chip. The differential signal lines 485+ / 485- are protected by TVS diodes D9-D13.

4. The onboard surge protection circuit based on multi-stage varistors and gas discharge tubes according to claim 1, characterized in that, The power module includes chip U3 (model HLK-5M05) and chip U4 (model AMS1117-3.3). The AC input is converted to 5V by chip U3 and then generated to 3.3V by U4 for use by the STM32F chip.

5. The on-board surge protection circuit based on multi-stage varistors and gas discharge tubes according to claim 4, characterized in that, The power module input terminal is equipped with a common mode choke L1-1 and a varistor R31, and gas discharge tubes F1-F2 are connected in parallel between the AC line and the PE ground.

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