A control circuit for an explosion-proof instrument

Abstract

This utility model relates to the field of safety circuit technology, specifically to a control circuit for an explosion-proof instrument. It includes a main control module for overall circuit control, a power supply module for supplying power and protecting the explosion-proof instrument in case of an accident, an isolation module for receiving and transmitting abnormal signals from corresponding working modules, and a communication module for communicating with a bus. The power supply module supplies power to the main control module, isolation module, and communication module. The signal output terminal of the isolation module and the data transmission terminal of the communication module are both connected to the main control module. The main control module is connected to the corresponding working modules through the isolation module. This utility model enables overall circuit control of the explosion-proof instrument, has a built-in power supply function, and achieves electrical isolation and communication through the isolation module. It features high integration, strong impact resistance, suitability for complex working environments, and effectively reduces later maintenance costs, resulting in high economic benefits.

Description

Technical Field

[0001] This utility model relates to the field of safety circuit technology, specifically to a control circuit for an explosion-proof instrument. Background Technology

[0002] Explosion-proof electrical instruments possess explosion-proof, shock-resistant, waterproof, and corrosion-resistant characteristics, making them suitable for pressure measurement and transmission in hazardous environments. They are typically manufactured using special materials, such as stainless steel, to ensure corrosion resistance. Equipped with explosion-proof housings and sealing devices, they ensure safety when used in explosive gas or dust environments. They also feature high accuracy, stability, and reliability, allowing for long-term operation in harsh environments. Instruments operating in harsh environments not only require a high level of sealing but also control circuits with better shock resistance. Furthermore, to reduce the workload of later maintenance, electrical isolation is necessary to ensure the safe and stable continuous operation of explosion-proof instruments in complex environments. Utility Model Content

[0003] The technical problem to be solved by this utility model is that existing explosion-proof instruments have a low safety factor, poor impact resistance, and a narrow range of applications.

[0004] To solve the above technical problems, this utility model adopts the following technical solution: a control circuit for an explosion-proof instrument, including a main control module for overall circuit control, a power supply module for supplying power and protecting the explosion-proof instrument in case of an accident, an isolation module for receiving and transmitting abnormal signals from the corresponding working modules, and a communication module for communicating with a bus. The power supply module supplies power to the main control module, the isolation module, and the communication module. The signal output terminal of the isolation module and the data transmission terminal of the communication module are both connected to the main control module. The main control module is connected to the corresponding working modules through the isolation module, and the main control module is connected to the corresponding bus through the communication module.

[0005] When in operation, this utility model can realize the overall circuit control of the explosion-proof instrument, with built-in power supply function. At the same time, it can realize electrical isolation and communication of the explosion-proof instrument through the isolation module. It has a high degree of integration, strong impact resistance, and is suitable for complex working environments. It can effectively reduce the cost of later maintenance and has high economic benefits.

[0006] Preferably, the power module includes a power management chip U7, an inductor L7, diodes D13, D14, D15, D16, and D17, resistors R6, R40, and R42, and capacitors C29, C33, C35, C36, C38, C39, and C86. The D port of the power management chip U7 is connected to the power supply via resistor R40 and grounded via capacitor C38. The D port of the power management chip U7 is connected to the S port of the power management chip U7 via resistor R6 and capacitor C29. The S port is connected to the first end of inductor L7 and is also connected to the first end of inductor L7 through capacitor C39, diode D15, and capacitor C36. The FB port of the power management chip U7 is connected to the first end of inductor L7 through capacitor C35 and is also connected to the first end of inductor L7 through resistor R42, diode D14, diode D17, and capacitor C36. The first end of inductor L7 is grounded through diode D13. The first end of inductor L7 is connected to the second end of inductor L7 through capacitor C36 and diode D16. The second end of inductor L7 outputs power and is grounded through capacitors C86 and C33 respectively.

[0007] Preferably, the power module includes a power management chip U3, a power management chip U45, a voltage regulator chip U4, inductors L4, LB3, L14, common-mode inductors L8 and L2, a fuse F1, diodes TVE1, D4, TVS2, D5, and D11, resistors R29, R411, and R33, and capacitors C81, C14, C82, C15, and C86. 3. Capacitors C16, C27, C25, C13, C32, C37, C41, C91, C19, C20, C17, C18, C40, C23, C22, C21, and C24. The HV_IN port of the power management chip U45 is connected to the first end of inductor L3 and grounded through capacitors C83 and C16 respectively. The second terminal of inductor L8 is connected to the second pin of common-mode inductor L8 and grounded through inductor L2 and capacitor C15 respectively. The first pin of inductor L8 is connected to the first terminal of the power supply through fuse F1 and diode D4. The first pin of inductor L8 is connected to the fourth pin of inductor L8 through diode TVS1, capacitor C81 and capacitor C14 respectively. The fourth pin of inductor L2 is connected to the second terminal of the power supply. The third pin of inductor L8 is connected to the third pin of inductor L2. The first pin of inductor L2 is connected to the first pin of inductor L8. The second pin of inductor L2 is connected to the second pin of inductor L8. The HV_IN port of power management chip U45 is connected to the XL1509_IN port of power management chip U45 through resistor R29 and resistor R411. The XL1509_IN port of power management chip U45 is connected to the first terminal of inductor L14 through resistor R411.

[0008] The first terminal of inductor L14 is grounded through capacitors C27, C25, C13, and resistor R33. The second terminal of inductor L14 is connected to the VIN port of power management chip U3 and grounded through capacitors C32, C37, C41, C91, C19, C22, and diode TVS2. The OUTPUT port of power management chip U3 is connected to the first terminal of inductor L4. The FEEDBACK port of power management chip U3 is connected to the second terminal of inductor L4. The first terminal of inductor L4 is grounded through diode D5. The second terminal of inductor L4 is connected to the first terminal of inductor LB3 through diode D11 and grounded through capacitors C17, C18, and C40. The second terminal of inductor LB3 is connected to the VIN port of voltage regulator chip U4 and grounded through capacitor C23. The VOUT port of voltage regulator chip U4 outputs power and is grounded through capacitors C22, C21, and C24.

[0009] Preferably, the isolation module includes several isolation circuits, the input terminals of which are respectively connected to the abnormal signal output terminals of their respective working modules, and the output terminals of which are all connected to the main control module.

[0010] Preferably, the isolation circuit includes an optocoupler isolation chip U8, a diode D3, resistors R46 and R47, and a capacitor C67. The anode of the input terminal of the optocoupler isolation chip U8 is connected to the abnormal signal output terminal of the corresponding working module through resistor R47 and diode D3. The cathode of the input terminal of the optocoupler isolation chip U8 is grounded. The collector of the output terminal of the optocoupler isolation chip U8 is connected to the PA5 port of the main control module and connected to the power supply through resistor R46. The emitter of the output terminal of the optocoupler isolation chip U8 is grounded and connected to the collector of the output terminal of the optocoupler isolation chip U8 through capacitor C67.

[0011] Preferably, the system also includes a card-swiping module for implementing the RF card-swiping function. The card-swiping module includes a card reader JP3, inductors L5 and L6, resistors R27, R28, R39, R41, and R44, and capacitors C61, C62, C63, C64, C65, and C66. The first pin of the card reader JP3 is connected to the power supply via inductor L5 and grounded via capacitor C61. The second pin of the card reader JP3 is connected to the first end of resistor R27. The second end of resistor R27 is connected to the PA8 port of the main control module and grounded via capacitor C62. The third pin of the card reader JP3 is grounded via inductor L6. The fourth pin of the card reader JP3 is connected to the first end of resistor R27. The first end of resistor R28 is connected, the second end of resistor R28 is connected to the SPI2_MISO port of the main control module and grounded through capacitor C63, the fifth pin of card reader JP3 is connected to the first end of resistor R39, the second end of resistor R39 is connected to the SPI2_MOSI port of the main control module and grounded through capacitor C64, the sixth pin of card reader JP3 is connected to the first end of resistor R41, the second end of resistor R41 is connected to the SPI2_SCK port of the main control module and grounded through capacitor C65, the seventh pin of card reader JP3 is connected to the first end of resistor R44, the second end of resistor R44 is connected to the SPI2_NSS port of the main control module and grounded through capacitor C66.

[0012] Preferably, the communication module includes a communication chip U1, a common-mode inductor L1, diodes TVS3 and TVS4, resistors R3, R4, R38, R13, R14, R17, R18, R19, R36, R37, R45, and R43, and capacitors C26, C2, and C4. The TXD port of the communication chip U1 is connected to the TIM4_CH4 port of the main control module via resistor R3 and grounded via capacitor C26. The RXD port of the communication chip U1 is connected to the TIM4_CH3 port of the main control module via resistor R4 and grounded via capacitor C28. The CANH port of the communication chip U1 is connected to the third pin of the common-mode inductor L1, and the fourth pin of the common-mode inductor L1 is connected to the communication bus via resistor R37. The first end of the common mode inductor L1 is connected to the third end of the communication bus via resistors R45 and R43. The fourth pin of the common mode inductor L1 is connected to the first end of resistor R17 and the first end of resistor R18, and is grounded via diode TVS4 and capacitor C4, respectively. The second ends of resistors R17 and R18 are both grounded via capacitor C5. The CANL port of the communication chip U1 is connected to the first pin of the common mode inductor L1. The second pin of the common mode inductor L1 is connected to the second end of the communication bus via resistors R19 and R36, respectively. The second pin of the common mode inductor L1 is connected to the first end of resistors R13 and R14, and is grounded via capacitor C2 and diode TVS3, respectively. The second ends of resistors R13 and R14 are both grounded via capacitor C5.

[0013] The beneficial technical effects of this utility model include:

[0014] This invention enables the overall circuit control of explosion-proof instruments, with built-in power supply function. It also achieves electrical isolation and communication of explosion-proof instruments through an isolation module. It has a high degree of integration, strong impact resistance, and is suitable for complex working environments. It can effectively reduce the cost of later maintenance and has high economic benefits.

[0015] Other features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the control circuit of an explosion-proof instrument;

[0018] Figure 2 The circuit structure diagram of the main control module;

[0019] Figure 3 Circuit structure of the power module Figure 1 ;

[0020] Figure 4 Circuit structure of the power module Figure 2 ;

[0021] Figure 5 This is the circuit structure diagram of the isolation module;

[0022] Figure 6 This is the circuit structure diagram of the communication module;

[0023] Figure 7 This is a circuit structure diagram of some modules in the control circuit of an explosion-proof instrument. Detailed Implementation

[0024] The technical solutions of the present utility model will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present utility model.

[0025] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” are used only to facilitate the description of the embodiments and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0026] Example 1:

[0027] Please see Figure 1 This embodiment discloses a control circuit for an explosion-proof instrument, including a main control module 1 for overall circuit control, a power supply module 2 for supplying power and protecting the explosion-proof instrument in case of an accident, an isolation module 3 for receiving and transmitting abnormal signals of the corresponding working modules, and a communication module 4 for communicating with the bus. The following is a detailed description in conjunction with the accompanying drawings.

[0028] Please see Figures 1 to 7 In this embodiment, the power module 2 supplies power to the main control module 1, the isolation module 3 and the communication module 4. The signal output terminal of the isolation module 3 and the data transmission terminal of the communication module 4 are both connected to the main control module 1. The main control module 1 is connected to the corresponding working module through the isolation module 3 and to the corresponding bus through the communication module 4.

[0029] When this embodiment is in operation, it can realize the overall circuit control of the explosion-proof instrument, with built-in power supply function. At the same time, through the isolation module 3, it can realize electrical isolation and communication of the explosion-proof instrument, etc. It has a high degree of integration, strong impact resistance, and is suitable for complex working environments. It can effectively reduce the cost of later maintenance and has high economic benefits.

[0030] Preferably, the isolation module 3 includes a plurality of isolation circuits 31, the input terminals of the plurality of isolation circuits 31 are respectively connected to the abnormal signal output terminals of their respective working modules, and the output terminals of the plurality of isolation circuits 31 are all connected to the main control module 1.

[0031] In specific implementation, the isolation circuit 31 includes an optocoupler isolation chip U8, a diode D3, a resistor R46, a resistor R47, and a capacitor C67. The anode of the input terminal of the optocoupler isolation chip U8 is connected to the abnormal signal output terminal of the corresponding working module through the resistor R47 and the diode D3. The cathode of the input terminal of the optocoupler isolation chip U8 is grounded. The collector of the output terminal of the optocoupler isolation chip U8 is connected to the PA5 port of the main control module 1 and connected to the power supply through the resistor R46. The emitter of the output terminal of the optocoupler isolation chip U8 is grounded and connected to the collector of the output terminal of the optocoupler isolation chip U8 through the capacitor C67.

[0032] As a further improvement to this embodiment, in order to enhance the safety level of the explosion-proof instrument and allow only authorized personnel to use it, and also to facilitate operator authentication, this embodiment further includes a card-swiping module 5 for implementing the RF card-swiping function. The card-swiping module 5 includes a card reader JP3, inductors L5 and L6, resistors R27, R28, R39, R41, and R44, and capacitors C61, C62, C63, C64, C65, and C66. The first pin of the card reader JP3 is connected to the power supply through inductor L5 and grounded through capacitor C61. The second pin of the card reader JP3 is connected to the first end of resistor R27, and the second end of resistor R27 is connected to the PA8 port of the main control module 1 and grounded through capacitor C62. The third pin of card reader JP3 is grounded through inductor L6. The fourth pin of card reader JP3 is connected to the first end of resistor R28. The second end of resistor R28 is connected to the SPI2_MISO port of main control module 1 and grounded through capacitor C63. The fifth pin of card reader JP3 is connected to the first end of resistor R39. The second end of resistor R39 is connected to the SPI2_MOSI port of main control module 1 and grounded through capacitor C64. The sixth pin of card reader JP3 is connected to the first end of resistor R41. The second end of resistor R41 is connected to the SPI2_SCK port of main control module 1 and grounded through capacitor C65. The seventh pin of card reader JP3 is connected to the first end of resistor R44. The second end of resistor R44 is connected to the SPI2_NSS port of main control module 1 and grounded through capacitor C66.

[0033] Preferably, a suitable communication circuit can be selected according to the actual application scenario. In this embodiment, the communication module 4 includes a communication chip U1, a common-mode inductor L1, diodes TVS3 and TVS4, resistors R3, R4, R38, R13, R14, R17, R18, R19, R36, R37, R45, R43, capacitors C26, C2, and C4. The TXD port of the communication chip U1 is connected to the TIM4_CH4 port of the main control module 1 through resistor R3 and grounded through capacitor C26. The RXD port of the communication chip U1 is connected to the TIM4_CH3 port of the main control module 1 through resistor R4 and grounded through capacitor C28. The CANH port of the communication chip U1 is connected to the third pin of the common-mode inductor L1. The four pins are connected to the first terminal of the communication bus via resistor R37 and to the third terminal of the communication bus via resistors R45 and R43. The fourth pin of the common-mode inductor L1 is connected to the first terminal of resistor R17 and the first terminal of resistor R18, and is grounded via diode TVS4 and capacitor C4, respectively. The second terminals of resistors R17 and R18 are both grounded via capacitor C5. The CANL port of communication chip U1 is connected to the first pin of common-mode inductor L1. The second pin of common-mode inductor L1 is connected to the second terminal of the communication bus via resistors R19 and R36, respectively. The second pin of common-mode inductor L1 is connected to the first terminal of resistors R13 and R14, and is grounded via capacitor C2 and diode TVS3, respectively. The second terminals of resistors R13 and R14 are both grounded via capacitor C5.

[0034] As a further improvement to this embodiment, in actual operation, the main control module 1 can use the MM32F0163D6P microcontroller, or it can be compatible with any suitable control chip such as the MM32F0144C6P microcontroller, the STM32F103C8 microcontroller, or the GD32F103C8T6 microcontroller. The communication module 4 can use the SIT1042T / 3 chip, and is also compatible with any suitable communication chip such as the TJA1051T / 3 chip, the TJA1042T / 3 chip, or the SIT1051T / 3 chip.

[0035] Example 2:

[0036] Please see Figure 3 and Figure 4 This embodiment provides a control circuit for an explosion-proof instrument. The similarities with other embodiments will not be repeated here. The differences will be described in detail below.

[0037] In this embodiment, to facilitate changes in the power supply method according to the site environment, high-voltage or low-voltage power supply can be selected as needed. In specific implementation, the power module 2 includes a power management chip U7, an inductor L7, diodes D13, D14, D15, D16, and D17, resistors R6, R40, and R42, and capacitors C29, C33, C35, C36, C38, C39, and C86. The D port of the power management chip U7 is connected to the power supply through resistor R40 and grounded through capacitor C38. The D port of the power management chip U7 is connected to the power supply through resistor R6 and capacitor C29. The S port of the power management chip U7 is connected to the first terminal of the inductor L7, and is also connected to the first terminal of the inductor L7 through capacitor C39, diode D15, and capacitor C36. The FB port of the power management chip U7 is connected to the first terminal of the inductor L7 through capacitor C35, and is also connected to the first terminal of the inductor L7 through resistor R42, diode D14, diode D17, and capacitor C36. The first terminal of the inductor L7 is grounded through diode D13. The first terminal of the inductor L7 is connected to the second terminal of the inductor L7 through capacitor C36 and diode D16. The second terminal of the inductor L7 outputs power and is grounded through capacitors C86 and C33 respectively.

[0038] Preferably, power module 2 includes power management chip U3, power management chip U45, voltage regulator chip U4, inductors L4, LB3, L14, common mode inductors L8 and L2, fuse F1, diodes TVE1, D4, TVS2, D5, and D11, resistors R29, R411, and R33, and capacitors C81, C14, C82, C15, C83, C16, C27, C25, C13, C32, C37, C41, C91, C19, C20, C17, C18, C40, C23, C22, C21, and C24. The HV_IN port of power management chip U45 is connected to the first end of inductor L3 and is connected via capacitors C83 and C14 respectively. 6. Grounding: The second terminal of inductor L8 is connected to the second pin of common-mode inductor L8 and grounded through inductor L2 and capacitor C15 respectively. The first pin of inductor L8 is connected to the first terminal of the power supply through fuse F1 and diode D4. The first pin of inductor L8 is connected to the fourth pin of inductor L8 through diode TVS1, capacitor C81 and capacitor C14 respectively. The fourth pin of inductor L2 is connected to the second terminal of the power supply. The third pin of inductor L8 is connected to the third pin of inductor L2. The first pin of inductor L2 is connected to the first pin of inductor L8. The second pin of inductor L2 is connected to the second pin of inductor L8. The HV_IN port of power management chip U45 is connected to the XL1509_IN port of power management chip U45 through resistor R29 and resistor R411. The XL1509_IN port of power management chip U45 is connected to the first terminal of inductor L14 through resistor R411.

[0039] The first terminal of inductor L14 is grounded through capacitors C27, C25, C13, and resistor R33. The second terminal of inductor L14 is connected to the VIN port of power management chip U3 and grounded through capacitors C32, C37, C41, C91, C19, C22, and diode TVS2. The OUTPUT port of power management chip U3 is connected to the first terminal of inductor L4. The FEEDBACK port of power management chip U3 is connected to the second terminal of inductor L4. The first terminal of inductor L4 is grounded through diode D5. The second terminal of inductor L4 is connected to the first terminal of inductor LB3 through diode D11 and grounded through capacitors C17, C18, and C40. The second terminal of inductor LB3 is connected to the VIN port of voltage regulator chip U4 and grounded through capacitor C23. The VOUT port of voltage regulator chip U4 outputs power and is grounded through capacitors C22, C21, and C24.

[0040] The beneficial technical effects of this embodiment include: the present invention can realize the overall circuit control of the explosion-proof instrument, has a built-in power supply function, and can realize electrical isolation and communication of the explosion-proof instrument through the isolation module. It has a high degree of integration, strong impact resistance, is suitable for complex working environments, can effectively reduce the cost of later maintenance, and has high economic benefits.

[0041] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the content described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. A control circuit for an explosion-proof instrument, characterized in that: The system includes a main control module (1) for overall circuit control, a power supply module (2) for powering the system and protecting the explosion-proof instrument in case of an accident, an isolation module (3) for receiving and transmitting abnormal signals from the corresponding working modules, and a communication module (4) for communicating with the communication bus. The power supply module (2) supplies power to the main control module (1), the isolation module (3), and the communication module (4). The signal output terminal of the isolation module (3) and the data transmission terminal of the communication module (4) are both connected to the main control module (1). The main control module (1) is connected to the corresponding working modules through the isolation module (3) and to the corresponding bus through the communication module (4).

2. The control circuit of an explosion-proof instrument according to claim 1, characterized in that: The power module (2) includes a power management chip U7, an inductor L7, diodes D13, D14, D15, D16, and D17, resistors R6, R40, and R42, and capacitors C29, C33, C35, C36, C38, C39, and C86. The D port of the power management chip U7 is connected to the power supply via resistor R40 and grounded via capacitor C38. The D port of the power management chip U7 is connected to the S port of the power management chip U7 via resistor R6 and capacitor C29. The S port of the power management chip U7... The port is connected to the first end of inductor L7 and is connected to the first end of inductor L7 through capacitor C39, diode D15, and capacitor C36. The FB port of the power management chip U7 is connected to the first end of inductor L7 through capacitor C35 and is connected to the first end of inductor L7 through resistor R42, diode D14, diode D17, and capacitor C36. The first end of inductor L7 is grounded through diode D13. The first end of inductor L7 is connected to the second end of inductor L7 through capacitor C36 and diode D16. The second end of inductor L7 outputs power and is grounded through capacitor C86 and capacitor C33 respectively.

3. The control circuit of an explosion-proof instrument according to claim 1, characterized in that: The power module (2) includes a power management chip U3, a power management chip U45, a voltage regulator chip U4, inductors L4, LB3, L14, common mode inductors L8 and L2, a fuse F1, diodes TVE1, D4, TVS2, D5, and D11, resistors R29, R411, and R33, and capacitors C81, C14, C82, C15, and C83. Capacitors C16, C27, C25, C13, C32, C37, C41, C91, C19, C20, C17, C18, C40, C23, C22, C21, and C24 are connected to the first end of inductor L3 via the HV_IN port of the power management chip U45, and grounded through capacitors C83 and C16 respectively. The second terminal of L8 is connected to the second pin of the common-mode inductor L8 and grounded through inductor L2 and capacitor C15 respectively. The first pin of inductor L8 is connected to the first terminal of the power supply through fuse F1 and diode D4. The first pin of inductor L8 is connected to the fourth pin of inductor L8 through diode TVS1, capacitor C81 and capacitor C14 respectively. The fourth pin of inductor L2 is connected to the second terminal of the power supply. The third pin of inductor L8 is connected to the third pin of inductor L2. The first pin of inductor L2 is connected to the first pin of inductor L8. The second pin of inductor L2 is connected to the second pin of inductor L8. The HV_IN port of the power management chip U45 is connected to the XL1509_IN port of the power management chip U45 through resistor R29 and resistor R411. The XL1509_IN port of the power management chip U45 is connected to the first terminal of inductor L14 through resistor R411. The first terminal of inductor L14 is grounded through capacitors C27, C25, C13, and resistor R33. The second terminal of inductor L14 is connected to the VIN port of power management chip U3 and grounded through capacitors C32, C37, C41, C91, C19, C22, and diode TVS2. The OUTPUT port of power management chip U3 is connected to the first terminal of inductor L4. The FEEDBACK port of power management chip U3 is connected to the second terminal of inductor L4. The first terminal of inductor L4 is grounded through diode D5. The second terminal of inductor L4 is connected to the first terminal of inductor LB3 through diode D11 and grounded through capacitors C17, C18, and C40. The second terminal of inductor LB3 is connected to the VIN port of voltage regulator chip U4 and grounded through capacitor C23. The VOUT port of voltage regulator chip U4 outputs power and is grounded through capacitors C22, C21, and C24.

4. The control circuit of an explosion-proof instrument according to claim 1, characterized in that: The isolation module (3) includes several isolation circuits (31), the input terminals of the several isolation circuits (31) are respectively connected to the abnormal signal output terminals of their respective working modules, and the output terminals of the several isolation circuits (31) are all connected to the main control module (1).

5. The control circuit of an explosion-proof instrument according to claim 4, characterized in that: The isolation circuit (31) includes an optocoupler isolation chip U8, a diode D3, a resistor R46, a resistor R47, and a capacitor C67. The anode of the input terminal of the optocoupler isolation chip U8 is connected to the abnormal signal output terminal of the corresponding working module through the resistor R47 and the diode D3. The cathode of the input terminal of the optocoupler isolation chip U8 is grounded. The collector of the output terminal of the optocoupler isolation chip U8 is connected to the PA5 port of the main control module (1) and connected to the power supply through the resistor R46. The emitter of the output terminal of the optocoupler isolation chip U8 is grounded and connected to the collector of the output terminal of the optocoupler isolation chip U8 through the capacitor C67.

6. The control circuit of an explosion-proof instrument according to claim 1, characterized in that: It also includes a card-swiping module (5) for implementing RF card-swiping functionality. The card-swiping module (5) includes a card reader JP3, inductors L5 and L6, resistors R27, R28, R39, R41, R44, capacitors C61, C62, C63, C64, C65, and C66. The first pin of the card reader JP3 is connected to the power supply through inductor L5 and grounded through capacitor C61. The second pin of the card reader JP3 is connected to the first end of resistor R27. The second end of resistor R27 is connected to the PA8 port of the main control module (1) and grounded through capacitor C62. The third pin of the card reader JP3 is grounded through inductor L6. The fourth pin of the card reader JP3 is connected to the first end of resistor R28. The first end is connected, the second end of the resistor R28 is connected to the SPI2_MISO port of the main control module (1) and grounded through capacitor C63, the fifth pin of the card reader JP3 is connected to the first end of the resistor R39, the second end of the resistor R39 is connected to the SPI2_MOSI port of the main control module (1) and grounded through capacitor C64, the sixth pin of the card reader JP3 is connected to the first end of the resistor R41, the second end of the resistor R41 is connected to the SPI2_SCK port of the main control module (1) and grounded through capacitor C65, the seventh pin of the card reader JP3 is connected to the first end of the resistor R44, the second end of the resistor R44 is connected to the SPI2_NSS port of the main control module (1) and grounded through capacitor C66.

7. The control circuit of an explosion-proof instrument according to claim 1, characterized in that: The communication module (4) includes a communication chip U1, a common-mode inductor L1, diodes TVS3 and TVS4, resistors R3, R4, R38, R13, R14, R17, R18, R19, R36, R37, R45, R43, capacitors C26, C2, and C4. The TXD port of the communication chip U1 is connected to the TIM4_CH4 port of the main control module (1) through resistor R3 and grounded through capacitor C26. The RXD port of the communication chip U1 is connected to the TIM4_CH3 port of the main control module (1) through resistor R4 and grounded through capacitor C28. The CANH port of the communication chip U1 is connected to the third pin of the common-mode inductor L1. The fourth pin of the common-mode inductor L1 is connected to the communication chip U1 through resistor R37. The first end of the bus is connected to the third end of the communication bus via resistors R45 and R43. The fourth pin of the common-mode inductor L1 is connected to the first end of resistors R17 and R18, and is grounded via diode TVS4 and capacitor C4, respectively. The second ends of resistors R17 and R18 are both grounded via capacitor C5. The CANL port of the communication chip U1 is connected to the first pin of the common-mode inductor L1. The second pin of the common-mode inductor L1 is connected to the second end of the communication bus via resistors R19 and R36, respectively. The second pin of the common-mode inductor L1 is connected to the first end of resistors R13 and R14, and is grounded via capacitor C2 and diode TVS3, respectively. The second ends of resistors R13 and R14 are both grounded via capacitor C5.

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