Explosion-proof and intrinsic safety type emergency sign lamp

Abstract

The utility model relates to the technical field of emergency sign lamps, in particular to an explosive-proof and intrinsic safety type emergency sign lamp which comprises an intrinsic safety cavity and an explosive-proof cavity, a lamp panel PCB is arranged in the intrinsic safety cavity, and a mainboard PCB is arranged in the explosive-proof cavity; an intrinsic safety circuit module is arranged on the lamp panel PCB; a safety barrier power supply module, a constant current control module, a step-down voltage stabilization module and a main control module are arranged on the mainboard PCB; the output negative electrode of each path of safety barrier power supply module is grounded; the constant-current control module is located at the front end of the safety barrier power supply module, the input end of the constant-current control module is connected with a direct-current bus, and the output end of the constant-current control module is connected with the input end of the safety barrier power supply module; and the intrinsic safety circuit module is connected with the safety barrier power supply module and is driven by the constant current control module. According to the invention, the problems that the explosion-proof and intrinsic safety type equipment generally comprises an explosion-proof cavity and an intrinsic safety cavity, the structure is complicated, and the cost and the volume are increased due to independent layout of multiple paths of safety barriers are solved.

Description

Technical Field

[0001] This application relates to the field of emergency sign lighting technology, and more specifically, to an explosion-proof and intrinsically safe emergency sign lighting device. Background Technology

[0002] In recent years, with the rapid development of technology, the number of tall and complex intelligent buildings has been increasing, leading to a continuous increase in the variety of fire emergency lighting fixtures used, with constantly improving performance and significantly enhanced technical levels, resulting in their widespread application and development. With the continuous upgrading and mandatory certification of national standards such as GB 17945-2024 Fire Emergency Lighting and Evacuation Guidance Systems and GB / T 3836-2021 Explosive Atmospheres, the requirements for fire emergency lighting fixtures are becoming increasingly stringent, especially for explosion-proof products used in special locations.

[0003] The explosion-proof emergency sign lights described in this application are primarily used in flammable and explosive environments, such as chemical, petroleum, natural gas, and coal mines, to ensure clear indication in emergency situations. These locations typically contain explosive gases or dust; using ordinary lighting fixtures in these environments may cause fires or explosions. Therefore, explosion-proof emergency sign lights are necessary to reduce safety risks. The most common explosion-proof types on the market are flameproof, intrinsically safe, and flameproof and intrinsically safe.

[0004] Explosion-proof enclosures primarily consist of a heavy, explosion-proof shell to withstand the explosion pressure of internal gases and prevent the internal explosion from propagating to the outside. The requirements for the internal circuitry and components are not high. These devices are relatively large and heavy, making installation and maintenance more difficult. Due to the enclosure's limitations, heat dissipation is poor, which may affect the equipment's lifespan.

[0005] Intrinsically safe devices primarily limit the energy within the equipment to prevent the generation of electrical sparks and thermal effects sufficient to ignite an explosive gas mixture under any circumstances. This is achieved through the use of low voltage, low current, and low power. The equipment's circuitry typically employs specialized designs and components to ensure that its energy remains within safe limits under both normal operating and fault conditions. Furthermore, the enclosure of intrinsically safe equipment must meet certain protection requirements to prevent external factors from damaging the internal circuitry. Such equipment places very high demands on its circuitry and components, resulting in relatively high costs; due to energy limitations, its output power and signal strength may be weaker.

[0006] Explosion-proof and intrinsically safe equipment combines the explosion-proof and intrinsically safe properties of both types. During normal operation, the internal safety barriers and intrinsically safe circuitry ensure that no electrical sparks or thermal effects sufficient to ignite an explosive gas mixture are generated. In the event of an explosion due to an internal malfunction, the explosion-proof enclosure can withstand the explosion pressure without damage and will not propagate the explosion to the surrounding environment. This type of equipment typically includes both an explosion-proof chamber and an intrinsically safe chamber, and its structure is usually quite complex. It requires both the robust enclosure and excellent explosion-proof performance of explosion-proof equipment, as well as the low-energy circuitry and special protective measures of intrinsically safe equipment. For example, explosion-proof and intrinsically safe equipment typically consists of an explosion-proof enclosure, an intrinsically safe circuit module, and a safety barrier power module, with strict isolation and protection between the modules. This type of equipment combines the advantages of both explosion-proof and intrinsically safe types, offering a high level of protection and safety. It is suitable for complex working environments and can meet various explosion-proof requirements. In some locations with extremely high explosion-proof performance requirements, explosion-proof and intrinsically safe equipment is the only option. Utility Model Content

[0007] The technical problem to be solved by this application is how to provide a robust housing with explosion-proof equipment and good explosion-proof performance, while also having low-energy circuits and special protection measures for intrinsically safe equipment. In view of the above-mentioned defects of the prior art, an explosion-proof and intrinsically safe emergency sign light is provided.

[0008] The technical solution adopted by this application to solve its technical problem is:

[0009] An intrinsically safe and explosion-proof emergency sign light includes an intrinsically safe cavity and an explosion-proof cavity. A light board PCB is disposed in the intrinsically safe cavity, and a main board PCB is disposed in the explosion-proof cavity. An intrinsically safe circuit module is disposed on the light board PCB. A safety barrier power supply module, a constant current control module, a step-down voltage regulator module, and a main control module are disposed on the main board PCB. The negative output of each of the safety barrier power supply modules is grounded.

[0010] The constant current control module is located at the front end of the safety barrier power module. The input terminal of the constant current control module is connected to the DC bus, and the output terminal is connected to the input terminal of the safety barrier power module.

[0011] The intrinsically safe circuit module is connected to the safety barrier power supply module and is driven by the constant current control module.

[0012] Preferably, the constant current control module includes parallel voltage divider resistors R27 and R34, transistors Q7, Q3, and Q6, and filter capacitor C15.

[0013] The voltage divider resistors R27 and R34 are connected in parallel between the base and emitter of transistor Q7; resistor R21 is connected to the base of transistor Q7, and resistor R23 is connected to the collector.

[0014] The emitter of transistor Q3 is connected to the voltage divider node of voltage divider resistors R27 and R34, the base is connected to resistor R22, and the collector is connected to the supply voltage VCC1.

[0015] The collector of transistor Q6 is connected to resistor R23, the base is connected to resistor R25 and then to resistor R24, and the emitter is connected to resistor R25 and then grounded.

[0016] The filter capacitor C15 is used for AD sampling filtering. A resistor R30 is connected in parallel with capacitor C15 and then grounded. A resistor R28 is connected between capacitor C15 and transistor Q3. A resistor R31 is connected to capacitor C15. The end of resistor R31 is connected to the ADLED2 pin of the main control module for AD sampling to determine faults. A resistor R32 is connected between power supply V1 and power supply VCC1.

[0017] Preferably, the step-down voltage regulator module includes a voltage regulator chip U1, an input filter capacitor C1 and a filter capacitor C4, an energy storage inductor L3, a feedback resistor R4, a feedback resistor R29 and a feedback resistor R10, and an output filter capacitor C6 and a filter capacitor C14.

[0018] A resistor R3 is connected between the VIN and EN pins of the voltage regulator chip U1, followed by a resistor R6, and then grounded. A capacitor C3 is connected to the BST pin, which is connected to the input terminal of the energy storage inductor L3. A diode D2 is connected to the SW pin, which is connected to the energy storage inductor L3, and then grounded.

[0019] Feedback resistors R29, R4, and R10 are connected in series and grounded, and are connected to the output terminal of energy storage inductor L3. The FB pin of voltage regulator chip U1 is connected between feedback resistors R4 and R10.

[0020] Preferably, the main control module includes 9 pins, wherein the PA0 pin is the ADLED2 pin, used for chip programming or access, and used for AD sampling during normal operation. It is connected to the output of the constant current control module through R31 and R28.

[0021] The PA1 pin is the DAT ADLED1 pin, used for data transmission. During normal operation, it is used for AD sampling and is connected to the output of the constant current control module through R50 and R52.

[0022] The PA2 pin is the ADLED3 pin. The PA2 pin is connected to the output of the constant current control module through R55 and R53. It is used for AD sampling during normal operation.

[0023] A capacitor C8 is connected between the VDD pin and the GND pin; the PA7 pin is the code return control pin; the PA6 pin is the decoding function module, used to process the encoded signal; the PA4 pin is the external reset pin; resistors R1 and R5 are connected between the PA4 pin and the VDD pin; a filter capacitor C7 is connected between resistors R1 and R5; and the output of the filter capacitor C7 is grounded.

[0024] A status indicator LED30 is connected to a resistor R33 on pin PC1, and LED30 is grounded.

[0025] Preferably, the safety barrier power module includes a fuse F2, Zener diodes ZD2-ZD4, and a current-limiting resistor RW1. The input pin of the fuse F2 is connected to the output pin of the constant current control module, and the output pin is connected to the cathode of the three parallel Zener diodes ZD2-ZD4.

[0026] The anodes of the Zener diodes ZD2-ZD4 are grounded together, and the cathodes of the Zener diodes ZD2-ZD4 are connected to one end of the current-limiting resistor RW1.

[0027] The end of the current-limiting resistor RW1 is connected to the power supply input terminal of the intrinsically safe circuit module.

[0028] Preferably, the intrinsically safe circuit includes an LED1-LED9 matrix for indicating status; the intrinsically safe circuit is independently grounded.

[0029] Preferably, it includes at least three independent safety barrier power supply modules and three independent intrinsically safe circuit modules, with the input terminal of each safety barrier power supply module independently connected to different pins of the output terminal of the constant current control module.

[0030] Preferably, the device includes a metal casing and a profile rod. The profile rod is connected to the side of the metal casing in the direction of its extension. An inner plug is threaded to the end opening of the profile rod, and an explosion-proof cavity is formed between the profile rod and the metal casing. An intrinsically safe cavity is formed in the middle of the metal casing. An external cable is provided at the end of the profile rod. The external cable extends into the explosion-proof cavity and is electrically connected to the mainboard PCB.

[0031] Preferably, the constant current control module uses a parallel resistor structure to achieve constant current output, satisfying I 恒定 =V BE / R, where R is the equivalent resistance of the parallel resistors R27 and R34;

[0032] The fuse F2 employs dual selection constraints, with the first constraint being I. 保险 *(1-5%)*(1-30%)≥I 恒定 The second constraint is I.保险 *1.7 < Zener diode's maximum operating current I ZM The selection accuracy of the fuse F2 is 5%, and a 30% redundancy is set to ensure that the Zener diode will not burn out before the transient high current fuse F2 is activated, and the voltage output will still be regulated.

[0033] The buck regulator module is configured with a redundant parallel structure according to intrinsic safety protection levels: ≥3 parallel connections for level ia, ≥2 parallel connections for level ib, and a single connection for level ic; the power design of the buck regulator module meets the following requirements: P 稳压管 ≥I 保险 *1.7* (V 稳压管 *105%)*1.5, where 1.5 is the safety factor, and parallel branches use series devices to achieve power sharing;

[0034] The power design of the current-limiting resistor RW1 meets P. RW1 =(V 稳压管 *105% 2 / R RW1 * (1-5%), and meets the requirements of the spark test.

[0035] Preferably, the end of the explosion-proof cavity is sealed with epoxy resin, and the surface of the lamp board PCB is coated with a layer of epoxy resin putty. The epoxy resin putty coating thickness is 0.5-1mm and completely covers the solder joints of the lamp board PCB circuit module. The epoxy resin sealing thickness is ≥2mm and covers all wire holes and seams in the explosion-proof cavity.

[0036] The beneficial effects of this application are as follows:

[0037] 1. The single or multiple standard safety barrier power modules are laid out separately from the main control circuit on the same motherboard PCB, and the motherboard PCB is placed in the explosion-proof cavity; when multiple safety barriers coexist, they are independent of each other, which can effectively ensure the safety of each intrinsically safe circuit module, while also reducing product size and cost.

[0038] 2. The constant current control module is placed at the front end of the safety barrier, and the negative output terminal of the safety barrier power module is strictly grounded, which greatly reduces safety risks. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the present application will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1This is a schematic diagram of the overall structure of the explosion-proof and intrinsically safe emergency sign light fixture according to an embodiment of this application.

[0041] Figure 2 This is a schematic diagram of the structure of a single-channel safety barrier power supply module connected to a single-channel intrinsically safe circuit module according to an embodiment of this application.

[0042] Figure 3 This is a schematic diagram of the structure of a multi-channel safety barrier power supply module connected to a multi-channel intrinsically safe circuit module according to an embodiment of this application.

[0043] Figure 4 This is a schematic diagram of a single-channel safety barrier configuration circuit according to an embodiment of this application.

[0044] Figure 5 and Figure 6 This is a schematic diagram of the three-way safety barrier configuration circuit in embodiment three of this application.

[0045] Explanation of reference numerals in the attached drawings: 1. Metal casing; 2. Profile rod; 3. Lamp board PCB; 4. Explosion-proof cavity; 5. Intrinsically safe cavity; 6. External wiring component; 7. Epoxy resin sealant; 8. Epoxy resin putty; 9. Inner plug; 10. Main board PCB. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of this application. Obviously, the described embodiments are some embodiments of this application, but not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0047] This application discloses an explosion-proof and intrinsically safe emergency sign light fixture. (Reference) Figure 1 It includes a metal shell 1 and a profile rod 2. The profile rod 2 is connected to the side of the metal shell 1 in the extension direction. An inner plug 9 is threaded to the end opening of the profile rod 2, and an explosion-proof cavity 4 is formed between the profile rod 2 and the metal shell 1. An intrinsically safe cavity 5 is formed in the middle of the metal shell 1. A lamp board PCB 3 is installed inside the intrinsically safe cavity. An external connection cable is installed at the end of the profile rod 2. The external connection cable extends into the explosion-proof cavity 4 and is electrically connected to the main board PCB 10.

[0048] The end of the explosion-proof cavity 4 is provided with epoxy resin sealant 7, and the surface of the lamp board PCB3 is coated with a layer of epoxy resin putty 8. The epoxy resin putty 8 has a coating thickness of 0.5-1mm and completely covers the solder joints of the circuit module of the lamp board PCB3. The epoxy resin sealant thickness is ≥2mm and covers all wire holes and seams inside the explosion-proof cavity 4.

[0049] refer to Figure 2-6The explosion-proof cavity is equipped with a main board PCB10, the lamp board PCB3 is equipped with an intrinsically safe circuit module, and the main board PCB10 is equipped with a safety barrier power supply module, a constant current control module, a step-down voltage regulator module and a main control module.

[0050] The safety barrier power module includes fuse F2, Zener diodes ZD2-ZD4, and current-limiting resistor RW1. The input pin of fuse F2 is connected to the output pin of the constant current control module, and the output pin is connected to the cathode of the three parallel Zener diodes ZD1-ZD4. The anodes of Zener diodes ZD1-ZD4 are grounded together, and the cathodes of Zener diodes ZD2-ZD4 are connected to one end of current-limiting resistor RW1. The end of current-limiting resistor RW1 is connected to the power input of the intrinsically safe circuit module.

[0051] The fuse F2 adopts dual selection constraints. The first constraint is Ifuse * (1-5%) * (1-30%) ≥ Iconstant. The second constraint is Ifuse * 1.7 < IZM, the maximum operating current of the Zener diode. The selection accuracy of the fuse F2 is 5%, and a 30% redundancy is set to ensure that the Zener diode will not burn out before the transient high current fuse F2 is activated, and the voltage output will still be regulated.

[0052] The constant current control module is located at the front end of the safety barrier power supply module. The input of the constant current control module is connected to the DC bus, and the output is connected to the input of the safety barrier power supply module.

[0053] The constant current control module includes two parallel voltage divider resistors R27 and R34, transistors Q7, Q3, and Q6, and a filter capacitor C15. Voltage divider resistors R27 and R34 are connected in parallel between the base and emitter of transistor Q7. The collector is connected to the supply voltage VCC1, and the base is connected to resistor R21. The base of transistor Q6 is connected to resistor R23, and after connecting to resistor R24, it is connected to resistor R24. The emitter is connected to resistor R25 and then grounded. Filter capacitor C15 is used for AD sampling filtering. A resistor R30 is connected in parallel to filter capacitor C15 and then grounded. A resistor R28 is connected between filter capacitor C15 and transistor Q3. A resistor R31 is connected to the end of filter capacitor C15, and the end of resistor R31 is connected to the ADLED2 pin of the main control module for AD sampling fault detection. A resistor R32 is connected between power supply V1 and the power supply VCC1.

[0054] By sampling the voltage of VCC1, the intrinsically safe circuit module is determined to be in a normal, short-circuit, or open-circuit state. If it is in a short-circuit state, it will output a low level through the LD1 pin to turn off transistor Q6, and then turn off transistor Q3 in the main path, thereby playing a protective role.

[0055] The constant current control module converts the current signal into a voltage signal by connecting two parallel voltage divider resistors R27 and R34 in series in the circuit. When the current in the main circuit increases, the voltage difference across the voltage divider resistors R27 and R34 increases. Once the conduction condition of transistor Q7 is met, the emitter and collector of transistor Q7 conduct, and current flows from V1 through transistor Q7, through resistor R23 and transistor Q6, and then to ground. The voltage across resistor R23 increases, which in turn increases the base voltage of transistor Q3 in the main circuit, and the emitter voltage increases accordingly. As a result, the voltage difference across resistor R27 decreases, and the current in the main circuit decreases, thus achieving negative feedback constant current.

[0056] The constant current control module uses a parallel resistor structure to achieve constant current output, satisfying I constant = VBE / R, where R is the equivalent resistance of the parallel resistor R27 and the resistor R34.

[0057] The main control module includes 9 pins. Among them, PA0 is the ADLED2 pin, connected to resistor R31 at the output of the constant current control module, used for chip programming or access, and used for AD sampling during normal operation; PA1 is the DAT ADLED1 pin, used for data transmission, and used for AD sampling during normal operation, connected to the constant current power supply module through resistor R52; PA2 is the ADLED3 pin, connected to the constant current power supply module through resistor R55; a capacitor C8 is connected between the VDD pin and the GND pin; PA7 is the code return control pin; PA6 is the decoding function module pin, used for processing encoded signals; PA4 is the external reset pin; resistors R1 and R5 are connected between PA4 and the VDD pin; a filter capacitor C7 is connected between resistors R1 and R5; the output of filter capacitor C7 is grounded; a capacitor R33 is connected to the PC1 pin, followed by a status indicator LED30, which is grounded.

[0058] The step-down voltage regulator module includes a voltage regulator chip U1, input filter capacitors C1 and C4, an energy storage inductor L3, feedback resistors R4, R29, and R10, and output filter capacitors C6 and C14. A resistor R3 is connected between the VIN and EN pins of the voltage regulator chip U1, followed by resistor R6, and then grounded. A capacitor C3 is connected to the BST pin and is connected to the input terminal of the energy storage inductor L3. The SW pin is connected to the output terminal of the energy storage inductor L3. The FB pin of the voltage regulator chip U1 is located between the feedback resistors R4 and R10.

[0059] The buck regulator module is configured with a redundant parallel structure according to the intrinsic safety protection level: ia level is configured with ≥3 parallel channels, ib level is configured with ≥2 parallel channels, and ic level is configured with a single channel; the power design of the buck regulator module meets the following requirements: P Zener diode ≥ I fuse * 1.7 * (V Zener diode * 105%) * 1.5, where 1.5 is the safety factor, and the parallel branches use series devices to achieve power sharing;

[0060] The current-limiting resistor RW1 is designed to meet the power requirements of PRW1 = (V Zener diode * 105%)² / RRW1 * (1 - 5%) and also meets the requirements of the spark test.

[0061] The intrinsically safe circuit module is connected to the safety barrier power supply module and is driven by the constant current control module. The intrinsically safe circuit module is independently grounded and includes an LED1-LED9 matrix, which is used to indicate the status.

[0062] As an optional embodiment, this application includes at least three independent safety barrier power modules and three independent intrinsically safe circuit modules that are connected in a one-to-one correspondence. Each safety barrier power module has the same structure and is independent of the others. The input terminal of each safety barrier power module is independently connected to a constant current control module, and the negative output terminal of each safety barrier power module is grounded.

[0063] The implementation principle of an explosion-proof and intrinsically safe sign light fixture according to an embodiment of this application is as follows: a single or multiple standard safety barrier power supply module and the main control circuit are separately laid out on the same motherboard PCB10 and placed in the explosion-proof cavity 4. After current limiting, the single standard safety barrier power supply module outputs a set of power supply to the intrinsically safe circuit module to ensure the output safety of the intrinsically safe circuit module.

[0064] When multiple safety barrier power modules coexist, they are completely independent of each other, ensuring the safety of each intrinsically safe output and preventing interference. The constant current control module is placed in the explosion-proof cavity 4 before the front-mounted safety barrier power module. It is used to continuously provide a constant current within a wide voltage input range to ensure that the brightness of the lamp surface meets the standard requirements. The current is sampled and converted into a voltage signal by a small resistor connected in series in the main circuit. The negative feedback path is formed by the PN junction voltage VBE of the transistor to realize the constant power supply of the main circuit with the set current. The MCU control module controls the opening or closing of the constant current module to realize the controlled light emission of the intrinsically safe LED.

[0065] The external power supply bus can be connected to a DC 20V-48V voltage range. A step-down voltage regulator circuit is used to output a fixed voltage. The specific output voltage can be adjusted according to the design of the safety barrier power module and the intrinsically safe circuit module. After the power supply signal passes through the step-down voltage regulator module, it enters the constant current control module, and then the safety barrier power module performs current limiting and voltage limiting processing to ensure that the energy entering the intrinsically safe circuit module meets the intrinsically safe requirements.

[0066] The intrinsically safe circuit module mainly consists of an LED matrix, which emits light using the current set by the constant current control module to meet the brightness requirements of emergency evacuation surfaces. The negative output of the safety barrier power module is grounded to ensure the safety and reliability of the intrinsically safe circuit. Multiple safety barrier power modules coexist on the same motherboard, but their outputs are independent and do not affect each other. The negative output of each safety barrier power module is connected to the same reference ground on the motherboard side, which solves the problem of increased cost and size caused by separate design and independent enclosure of multiple safety barrier power modules.

[0067] It can not only improve the problem of increased cost and size caused by the complex structure of explosion-proof and intrinsically safe equipment, including explosion-proof and intrinsically safe cavities, and the independent layout of multiple safety barriers; it can also correct the non-standard design of similar products on the market, such as the safety barrier power module not meeting the standard design requirements; and the problem of the safety barrier power module being directly connected to the constant current control module with the negative terminal, not being grounded as required, or the need to add an extra safety barrier to control the constant current control module.

[0068] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the scope of protection of the appended claims.

Claims

1. An explosion-proof and intrinsically safe emergency sign light, comprising an intrinsically safe cavity and an explosion-proof cavity, characterized in that, The intrinsically safe cavity is equipped with a lamp board PCB, and the explosion-proof cavity is equipped with a main board PCB; the lamp board PCB is equipped with an intrinsically safe circuit module; the main board PCB is equipped with a safety barrier power supply module, a constant current control module, a step-down voltage regulator module, and a main control module; the negative output of each of the safety barrier power supply modules is grounded; The constant current control module is located at the front end of the safety barrier power module. The input terminal of the constant current control module is connected to the DC bus, and the output terminal is connected to the input terminal of the safety barrier power module. The intrinsically safe circuit module is connected to the safety barrier power supply module and is driven by the constant current control module.

2. The explosion-proof and intrinsically safe emergency sign light according to claim 1, characterized in that, The constant current control module includes parallel voltage divider resistors R27 and R34, transistors Q7, Q3, and Q6, as well as filter capacitor C15. The voltage divider resistors R27 and R34 are connected in parallel between the base and emitter of transistor Q7; resistor R21 is connected to the base of transistor Q7, and resistor R23 is connected to the collector. The emitter of transistor Q3 is connected to the voltage divider node of voltage divider resistors R27 and R34, the base is connected to resistor R22, and the collector is connected to the supply voltage VCC1. The collector of transistor Q6 is connected to resistor R23, the base is connected to resistor R25 and then to resistor R24, and the emitter is connected to resistor R25 and then grounded. The filter capacitor C15 is used for AD sampling filtering. A voltage divider resistor R30 is connected in parallel with capacitor C15 and then grounded. A voltage divider resistor R28 is connected between capacitor C15 and transistor Q3. A resistor R31 is connected to the end of capacitor C15. The end of resistor R31 is connected to the ADLED2 pin of the main control module for AD sampling to determine faults. A resistor R32 is connected between power supply V1 and power supply VCC1.

3. The explosion-proof and intrinsically safe emergency sign light according to claim 1, characterized in that, The step-down voltage regulator module includes a voltage regulator chip U1, an input filter capacitor C1 and a filter capacitor C4, an energy storage inductor L3, a feedback resistor R4, a feedback resistor R29 and a feedback resistor R10, and an output filter capacitor C6 and a filter capacitor C14. A resistor R3 is connected between the VIN and EN pins of the voltage regulator chip U1, followed by a resistor R6, and then grounded. A capacitor C3 is connected to the BST pin and is connected to the input terminal of the energy storage inductor L3. A diode D2 is connected to the SW pin and the connection node of the energy storage inductor L3, and then grounded. Feedback resistors R29, R4, and R10 are connected in series and grounded, and are connected to the output terminal of energy storage inductor L3. The FB pin of voltage regulator chip U1 is connected between feedback resistors R4 and R10.

4. The explosion-proof and intrinsically safe emergency sign light according to claim 2, characterized in that, The main control module includes 9 pins, of which PA0 is the ADLED2 pin, used for chip programming or access, and used for AD sampling during normal operation. It is connected to the output of the constant current control module through R31 and R28. The PA1 pin is the DAT ADLED1 pin, used for data transmission. During normal operation, it is used for AD sampling and is connected to the output of the constant current control module through R50 and R52. The PA2 pin is the ADLED3 pin. The PA2 pin is connected to the output of the constant current control module through R55 and R53. It is used for AD sampling during normal operation. A capacitor C8 is connected between the VDD pin and the GND pin; the PA7 pin is the code return control pin; the PA6 pin is the decoding function module, used to process the encoded signal; the PA4 pin is the external reset pin; resistors R1 and R5 are connected between the PA4 pin and the VDD pin; a filter capacitor C7 is connected between resistors R1 and R5; and the output of the filter capacitor C7 is grounded. A status indicator LED30 is connected to a resistor R33 on pin PC1, and LED30 is grounded.

5. An explosion-proof and intrinsically safe emergency sign light according to claim 2, characterized in that, The safety barrier power module includes a fuse F2, Zener diodes ZD2-ZD4, and a current-limiting resistor RW1. The input pin of the fuse F2 is connected to the output pin of the constant current control module, and the output pin is connected to the cathode of the three parallel Zener diodes ZD2-ZD4. The anodes of the Zener diodes ZD2-ZD4 are grounded together, and the cathodes of the Zener diodes ZD2-ZD4 are connected to one end of the current-limiting resistor RW1. The end of the current-limiting resistor RW1 is connected to the power supply input terminal of the intrinsically safe circuit module.

6. The explosion-proof and intrinsically safe emergency sign light according to claim 5, characterized in that, The intrinsically safe circuit module includes an LED1-LED9 matrix for indicating status; the intrinsically safe circuit is independently grounded.

7. An explosion-proof and intrinsically safe emergency sign light according to any one of claims 1-6, characterized in that, It includes at least three independent safety barrier power supply modules and three independent intrinsically safe circuit modules, with the input terminal of each safety barrier power supply module independently connected to different pins of the output terminal of the constant current control module.

8. The explosion-proof and intrinsically safe emergency sign light according to claim 1, characterized in that, It includes a metal shell and a profile rod. The profile rod is connected to the side of the metal shell in the extension direction. An inner plug is threaded to the end opening of the profile rod, and an explosion-proof cavity is formed between the profile rod and the metal shell. An intrinsically safe cavity is formed in the middle of the metal shell. An external cable is provided at the end of the profile rod. The external cable extends into the explosion-proof cavity and is electrically connected to the main board PCB.

9. An explosion-proof and intrinsically safe emergency sign light according to claim 5, characterized in that, The constant current control module uses a parallel resistor structure to achieve constant current output, satisfying I... 恒定 =V BE / R, where R is the equivalent resistance of the parallel resistors R27 and R34; The fuse F2 employs dual selection constraints, with the first constraint being I. 保险 *(1-5%)*(1-30%)≥I 恒定 The second constraint is I. 保险 *1.7 < Zener diode's maximum operating current I ZM The selection accuracy of the fuse F2 is 5%, and a 30% redundancy is set to ensure that the Zener diode will not burn out before the transient high current fuse F2 is activated, and the voltage output will still be regulated. The step-down voltage regulator module is configured with a redundant parallel structure according to the intrinsic safety protection level: ia level is configured with ≥3 parallel channels, ib level is configured with ≥2 parallel channels, and ic level is configured with a single channel. The power design of the buck regulator module satisfies: P 稳压管 ≥I 保险 *1.7* (V 稳压管 *105%)*1.5, where 1.5 is the safety factor, and parallel branches use series devices to achieve power sharing; The power design of the current-limiting resistor RW1 meets P. RW1 =(V 稳压管 *105% 2 / R RW1 * (1-5%), and meets the requirements of the spark test.

10. An explosion-proof and intrinsically safe emergency sign light according to claim 8, characterized in that, The explosion-proof cavity is sealed with epoxy resin at its end. The surface of the lamp board PCB is coated with a layer of epoxy resin putty with a thickness of 0.5-1mm, which completely covers the solder joints of the lamp board PCB circuit module. The epoxy resin sealant is ≥2mm thick and covers all wire holes and seams inside the explosion-proof cavity.

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