Intrinsic safety type RS485 full-isolation protection circuit device
By introducing the first intrinsic safety 485 module and the second intrinsic safety 485 module into the mining RS485 circuit, combined with the isolation and monostable trigger module, the problems of high circuit cost, complex operation, level mismatch and leakage are solved, and the circuit safety and reliability are achieved.
Patent Information
- Application Number
- CN202422215466.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-10
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-09-10
AI Technical Summary
The existing mining RS485 circuit has high cost, complex operation, mismatch in circuit levels and leakage in transmission.
The first intrinsic safety 485 module and the second intrinsic safety 485 module are adopted, combined with the isolation module and the monostable trigger module to avoid leakage and ensure that both ends of the circuit are RS485 interfaces, and level matching and conversion are achieved through the MAX485 chip and the NE555 chip.
Reduces circuit costs, simplifies operational complexity, avoids circuit leakage and level mismatch, and ensures circuit safety and reliability.
Smart Images
Figure CN223093664U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of intrinsically safe circuits for coal mines, and particularly relates to an intrinsically safe RS485 full isolation protection circuit device. Background Art
[0002] In the commonly used RS485 circuit in a mine controller, since it needs to be connected to other external devices, a full isolation intrinsically safe circuit design needs to be realized. Most of the existing technologies are serial port TTL to RS485 circuits, which control the transceiver enable terminals of the 485 chip through a processor. It cannot make both ends of the circuit be RS485 interfaces, and the processor will increase the cost and complexity of operation, and there will be problems of circuit level mismatch during transmission and circuit leakage during transmission. Summary of the Invention
[0003] In order to solve the problems of high cost and complex operation of the RS485 circuit, circuit level mismatch during transmission, and circuit leakage during transmission, the utility model provides an intrinsically safe RS485 full isolation protection circuit device. By setting a first intrinsically safe 485 module and a second intrinsically safe 485 module, the problem of circuit leakage during transmission is avoided, and both ends of the circuit are RS485 interfaces. There is no need to add a processor, which reduces the circuit cost and simplifies the operation complexity. By setting an isolation module, a first monostable trigger module, and a second monostable trigger module, the circuit level mismatch during transmission is avoided.
[0004] In order to achieve the above purpose, the technical solution of the utility model is as follows:
[0005] The utility model provides an intrinsically safe RS485 full isolation protection circuit device, including a hardware circuit, and the hardware circuit includes a first intrinsically safe 485 module, an isolation module, a first monostable trigger module, a second intrinsically safe 485 module, and a second monostable trigger module;
[0006] Both the first intrinsically safe 485 module and the second intrinsically safe 485 module include a control sub-module, a voltage stabilizing sub-module, and a current limiting sub-module. The output end of the control sub-module is connected to the input ends of the voltage stabilizing sub-module and the current limiting sub-module, which is convenient for stabilizing the voltage and limiting the current, and ensures the safety of the circuit;
[0007] The isolation module includes a first optocoupler and a second optocoupler, and the first optocoupler and the second optocoupler are respectively electrically connected to the first intrinsically safe 485 module and the second intrinsically safe 485 module, which is convenient for matching the levels in the circuit;
[0008] Both the first monostable trigger module and the second monostable trigger module include a second control sub-module, and the output end of the second control sub-module is connected to the input end of the isolation module, which is convenient for level conversion in the circuit.
[0009] Furthermore, the control sub-module includes a MAX485 chip, and the MAX485 chip is connected to the voltage regulation sub-module through serial ports A and B, which is used to stabilize the voltage of the control sub-module.
[0010] Furthermore, the voltage regulation sub-module includes multiple voltage regulator tube groups. The multiple voltage regulator tube groups are connected in parallel, and each voltage regulator tube group includes two voltage regulator tubes. The two voltage regulator tubes are connected in series, which is convenient for stabilizing the voltage and can effectively avoid potential safety hazards on the circuit ports.
[0011] Furthermore, the current limiting sub-module includes a first current limiting resistor and a second current limiting resistor. The first current limiting resistor and the second current limiting resistor are the same. The first current limiting resistor is connected to the MAX485 chip through serial port A, and the second current limiting resistor is connected to the MAX485 chip through serial port B, which is used to prevent potential safety hazards caused by excessive output current during transmission.
[0012] Furthermore, both the first opto-coupler and the second opto-coupler include EL357N opto-couplers. The first opto-coupler is connected to the first intrinsically safe 485 module through serial ports RE and DE, and the second opto-coupler is connected to the second intrinsically safe 485 module through serial ports RE and DE, which is convenient for level matching.
[0013] Furthermore, the second control sub-module includes an NE555 chip. In the first monostable trigger module, the NE555 chip is connected to the second opto-coupler through serial ports OUT and RST, and in the first monostable trigger module, the NE555 chip is connected to the first intrinsically safe 485 module through serial port RO. In the second monostable trigger module, the NE555 chip is connected to the first opto-coupler through serial ports OUT and RST, and in the second monostable trigger module, the NE555 chip is connected to the second intrinsically safe 485 module through serial port RO, which is convenient for level conversion.
[0014] Advantages of the present utility model:
[0015] (1) By setting the first intrinsically safe 485 module and the second intrinsically safe 485 module, the present utility model ensures the voltage stability of the circuit and limits the current magnitude, avoids the problem of circuit leakage, and ensures that both ends of the circuit are RS485 interfaces. There is no need to set a processor, which reduces the circuit cost and simplifies the operation complexity.
[0016] (2) By setting the isolation module, the first monostable trigger module and the second monostable trigger module, the present utility model avoids the level mismatch of the circuit during transmission and ensures the level conversion in the circuit. Description of the Drawings
[0017] Figure 1This is one of the electrical schematic diagrams of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0018] Figure 2 This is the electrical schematic diagram of the first intrinsically safe 485 module of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0019] Figure 3 This is the electrical schematic diagram of the first monostable trigger module of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0020] Figure 4 This is the electrical schematic diagram of the isolation module of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0021] Figure 5 This is the electrical schematic diagram of the second intrinsically safe 485 module of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0022] Figure 6 This is the electrical schematic diagram of the second monostable trigger module of an intrinsically safe RS485 full isolation protection circuit device provided by an embodiment of the present invention.
[0023] In the attached drawings, the reference numerals are: 1 is the isolation module, 2 is the second intrinsically safe 485 module, 3 is the first intrinsically safe 485 module, 4 is the first monostable trigger module, 5 is the second monostable trigger module, 6 is the control sub-module, 7 is the voltage stabilizing sub-module, 8 is the current limiting sub-module, 9 is the first optocoupler, 10 is the second optocoupler, and 11 is the second control sub-module. Detailed implementation manners
[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0025] Embodiment 1
[0026] As Figure 1-6As shown in the figure, an intrinsically safe RS485 full isolation protection circuit device includes a hardware circuit. This hardware circuit uses a wide voltage input range, with a voltage range of 9 - 32V. A 0.2A fuse is connected in series at the voltage input terminal. The working voltage of this circuit is 5V, and the working current is less than 50mA, fully meeting the design requirements in terms of power consumption. Both ends of the circuit are 485 interfaces.
[0027] The hardware circuit includes a first intrinsically safe 485 module 3, an isolation module 1, a first monostable trigger module 4, a second intrinsically safe 485 module 2, and a second monostable trigger module 5.
[0028] This circuit requires that both ends of the circuit are 485 interfaces. To meet this requirement, a first intrinsically safe 485 module 3 and a second intrinsically safe 485 module 2 are set up in this circuit. Both the first intrinsically safe 485 module 3 and the second intrinsically safe 485 module 2 include a control sub - module 6, a voltage - stabilizing sub - module 7, and a current - limiting sub - module 8. The output end of the control sub - module 6 is connected to the input ends of the voltage - stabilizing sub - module 7 and the current - limiting sub - module 8. Specifically, the control sub - module 6 includes a MAX485 chip. The MAX485 chip is connected to the voltage - stabilizing sub - module 7 through serial ports A and B, facilitating ensuring the voltage stability of the circuit. The voltage - stabilizing sub - module 7 includes three voltage - stabilizing diode groups. The three voltage - stabilizing diode groups are in parallel, and each voltage - stabilizing diode group includes two voltage - stabilizing diodes connected in series, making the maximum voltage - stabilizing value of the circuit 5.6V. The current - limiting sub - module 8 includes a first current - limiting resistor and a second current - limiting resistor. The first current - limiting resistor and the second current - limiting resistor are the same, with a resistance value of 20R and a power of 2W. The first current - limiting resistor is connected to the MAX485 chip through serial port A, and the second current - limiting resistor is connected to the MAX485 chip through serial port B, preventing potential safety hazards caused by excessive output current during transmission.
[0029] The isolation module 1 includes a first opto - coupler 9 and a second opto - coupler 10. The first opto - coupler 9 and the second opto - coupler 10 are electrically connected to the first intrinsically safe 485 module 3 and the second intrinsically safe 485 module 2 respectively. Specifically, both the first opto - coupler 9 and the second opto - coupler 10 include EL357N opto - couplers. The first opto - coupler 9 is connected to the first intrinsically safe 485 module 3 through serial ports RE and DE, and the second opto - coupler 10 is connected to the second intrinsically safe 485 module 2 through serial ports RE and DE.
[0030] In order to correspond to the first Ben'an 485 module 3 and the second Ben'an 485 module 2, the utility model is provided with a first monostable trigger module 4 and a second monostable trigger module 5. Both the first monostable trigger module 4 and the second monostable trigger module 5 include a second control sub-module 11, and the output end of the second control sub-module 11 is connected to the input end of the isolation module 1. Specifically, the second control sub-module 11 includes an NE555 chip. The TTL signal converted from the RS485 in the circuit is default high level and becomes low level when data is received. Therefore, the NE555 chip is adopted in the second control sub-module 11 to facilitate the timely conversion of the level. In the first monostable trigger module 4, the NE555 chip is connected to the second optocoupler 10 through the OUT and RST serial ports, and the NE555 chip in the first monostable trigger module 4 is connected to the first Ben'an 485 module 3 through the RO serial port. In the second monostable trigger module 5, the NE555 chip is connected to the first optocoupler 9 through the OUT and RST serial ports, and the NE555 chip in the second monostable trigger module 5 is connected to the second Ben'an 485 module 2 through the RO serial port.
[0031] Preferably, the utility model also sets enable control for the first Ben'an 485 module 3 and the second Ben'an 485 module 2. Specifically, the first monostable trigger module 4 is connected to the second Ben'an 485 module 2 through the RE and DE serial ports for the enable control of the second Ben'an 485 module 2. The second monostable trigger module 5 is connected to the first Ben'an 485 module 3 through the RE and DE serial ports for the enable control of the first Ben'an 485 module 3.
[0032] Embodiment 2
[0033] In actual application, the first Ben'an 485 module 3 and the second monostable trigger module 5 are used to ensure that both ends of the circuit are 485 interfaces, and six voltage regulators in the voltage stabilizing sub-module 7 are used to ensure the circuit voltage stabilization value, and the current limiting sub-module 8 limits the maximum value of the output current.
[0034] Since the circuit is provided with the first Ben'an 485 module 3 and the second Ben'an 485 module 2, and the 485 interfaces at both ends of the circuit need to be completely isolated, the utility model is provided with an isolation module 1. The isolation method adopted is that the levels of the 485 interfaces at both ends are first converted into TTL levels, and then after being isolated by the first optocoupler 9 and the second optocoupler 10, they are connected to the TTL-to-485 chip at the other end. When the TTL levels are accessed, they need to be cross-connected, that is, the input end of the first optocoupler 9 is connected to the output end of the second optocoupler 10, and the output end of the first optocoupler 9 is connected to the input end of the second optocoupler 10.
[0035] When the first monostable trigger module 4 and the second monostable trigger module 5 are used for enabling control, the circuit output of the present utility model defaults to a low level. When it is detected that the input signal is low level, that is, data is received, the NE555 chip outputs a high level. After being isolated by the isolation module 1, it controls the transceiver enable terminal of the MAX485 chip interface chip, so that the 485 interface at the opposite end is immediately in the sending state, ensuring the normal transmission of data. When the input signal ends and no new data is received within 2 ms, it means that the current data reception and transmission are completed. At this time, the output terminal of the NE555 chip automatically returns to the low level, making both 485 interfaces at both ends of the circuit in the receiving state.
[0036] The 2 ms delay in the circuit is mainly achieved by the capacitor in the circuit. When the input is at a low level, the charge stored on the capacitor will be immediately released, and the NE555 chip will output a high level without any delay. When the input signal becomes high level, the capacitor needs to be charged first. When the charging is completed, the level on the input pin will slowly rise until the output becomes low level. After calculation and testing, the delay of a 10 nF capacitor is 2 ms, meeting the design requirements.
[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model.
Claims
1. An intrinsically safe RS485 fully isolated protection circuit device, characterized in that, It includes a first intrinsically safe 485 module (3), an isolation module (1), a first monostable trigger module (4), a second intrinsically safe 485 module (2), and a second monostable trigger module (5); Both the first intrinsically safe 485 module (3) and the second intrinsically safe 485 module (2) include a control sub-module (6), a voltage stabilizing sub-module (7), and a current limiting sub-module (8). The output end of the control sub-module (6) is connected to the input ends of the voltage stabilizing sub-module (7) and the current limiting sub-module (8); The isolation module (1) includes a first opto-coupler (9) and a second opto-coupler (10). The first opto-coupler (9) and the second opto-coupler (10) are electrically connected to the first intrinsically safe 485 module (3) and the second intrinsically safe 485 module (2) respectively; Both the first monostable trigger module (4) and the second monostable trigger module (5) include a second control sub-module (11). The output end of the second control sub-module (11) is connected to the input end of the isolation module (1).
2. The intrinsically safe RS485 fully isolated protection circuit device according to claim 1, characterized in that The control sub-module (6) includes a MAX485 chip. The MAX485 chip is connected to the voltage stabilizing sub-module (7) through serial ports A and B.
3. The intrinsically safe RS485 fully isolated protection circuit device according to claim 1, characterized in that, The voltage stabilizing sub-module (7) includes multiple voltage stabilizing tube groups. The multiple voltage stabilizing tube groups are connected in parallel. Each voltage stabilizing tube group includes two voltage stabilizing tubes, and the two voltage stabilizing tubes are connected in series.
4. The intrinsically safe RS485 fully isolated protection circuit device according to claim 1, characterized in that, The current limiting sub-module (8) includes a first current limiting resistor and a second current limiting resistor. The first current limiting resistor and the second current limiting resistor are the same. The first current limiting resistor is connected to the MAX485 chip through serial port A, and the second current limiting resistor is connected to the MAX485 chip through serial port B.
5. An intrinsically safe RS485 fully isolated protection circuit device according to claim 1, characterized in that, Both the first opto-coupler (9) and the second opto-coupler (10) include EL357N opto-couplers. The first opto-coupler (9) is connected to the first intrinsically safe 485 module (3) through serial ports RE and DE, and the second opto-coupler (10) is connected to the second intrinsically safe 485 module (2) through serial ports RE and DE.
6. The intrinsically safe RS485 fully isolated protection circuit device according to claim 1, characterized in that, The second control sub-module (11) includes an NE555 chip. In the first monostable trigger module (4), the NE555 chip is connected to the second opto-coupler (10) through serial ports OUT and RST, and in the first monostable trigger module (4), the NE555 chip is connected to the first intrinsically safe 485 module (3) through serial port RO. In the second monostable trigger module (5), the NE555 chip is connected to the first opto-coupler (9) through serial ports OUT and RST, and in the second monostable trigger module (5), the NE555 chip is connected to the second intrinsically safe 485 module (2) through serial port RO.