CN204349965U - A kind of 485 buffer circuits - Google Patents
A kind of 485 buffer circuits Download PDFInfo
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- CN204349965U CN204349965U CN201420831285.9U CN201420831285U CN204349965U CN 204349965 U CN204349965 U CN 204349965U CN 201420831285 U CN201420831285 U CN 201420831285U CN 204349965 U CN204349965 U CN 204349965U
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Abstract
A kind of 485 buffer circuits of the present utility model; except being equipped with filter capacitor and communicating except indicating circuit; devise 485 protectors at the output of chip ADM2587, discharge tube, current-limiting resistance R13, R15, Transient Suppression Diode D1, D2, D3 carry out protect IC, utilize inductance L 4, inductance L 5 to eliminate interference.Owing to utilizing single-chip to carry out practical function, and set up safeguard measure, make the fault of whole circuit less, the life-span is longer, and cost is lower.
Description
Technical field
The utility model relates to 485 communications fields, specifically a kind of 485 buffer circuits.
Background technology
At electronic circuit, in the electronic circuit of particularly Industry Control, in order to realize the exchanges data with outside port, usually need to arrange 485 buffer circuits to realize the forwarding of data, on the one hand, prevent other data from leaking, on the other hand, prevent external voltage electric current to the damage of control appliance.But, existing 485 buffer circuits realize cost higher, form complicated and protected effect general, existing demand can not be met.
Utility model content
In order to solve the above problems, the utility model provides a kind of 485 buffer circuits, not only solves the problem that cost is high, protective is poor, and has the adjustable function of terminal distance matching distance.
The utility model is by the following technical solutions: a kind of 485 buffer circuits, comprise chip ADM2587, the RX pin of chip ADM2587 connects RXD bus, the TX pin of chip ADM2587 connects TXD bus, the DE pin of chip ADM2587 connects second pin of inverter 74HC04, first pin of inverter 74HC04 connects RXD bus, 2nd pin of chip ADM2587 is by electric capacity C33 ground connection, 8th pin of chip ADM2587 connects the 2nd pin of chip ADM2587, the 1st of chip ADM2587, 3, 9, 10, 11, 14, 16, the equal ground connection of 20 pin, electric capacity C32, electric capacity C31 is in parallel with electric capacity C33 respectively, 12nd pin of chip ADM2587 is by electric capacity C36 ground connection, 19th pin of chip ADM2587 connects the 12nd pin of chip ADM2587, electric capacity C34, electric capacity C35 is in parallel with electric capacity C36 respectively, 15th pin of chip ADM2587 is by resistance R15 ground connection, 18th pin of chip ADM2587 meets VDD by resistance R12, 13rd pin of chip ADM2587 connects the 18th pin of chip ADM2587, 17th pin of chip ADM2587 connects the 15th pin of chip ADM2587, an input of 485 protectors connects the 18th pin of ADM2587 by resistance R13, and connect the first output by inductance L 4, another input of 485 protectors connects the 15th pin of ADM2587 by resistance R14, and connect the second output by inductance L 5, the earth terminal ground connection of 485 protectors, the negative pole of voltage stabilizing didoe D1 connects the first output, the positive pole of voltage stabilizing didoe D1 connects the negative pole of the second output and voltage stabilizing didoe D2 respectively, the plus earth of voltage stabilizing didoe D2, the negative pole of voltage stabilizing didoe D3 connects the first output, the plus earth of voltage stabilizing didoe D3, the two ends of discharge tube connect the first output and the second output respectively, the earth terminal ground connection of discharge tube, 3rd pin of inverter 74HC04 connects RXD bus, 4th pin of inverter 74HC04 connects LED1 positive pole, LED1 negative pole connecting resistance R17 one end, resistance R17 other end ground connection, 5th pin of inverter 74HC04 connects TXD bus, 6th pin of inverter 74HC04 connects LED2 positive pole, LED2 negative pole connecting resistance R18 one end, resistance R18 other end ground connection, 2nd pin of chip ADM2587 connects 5V voltage vcc, and the 12nd pin of chip ADM2587 meets VDD.
Further, described circuit also comprises resistance R16 and K switch 1, termination first output of resistance R16, another termination K switch 1 one end of resistance R16, another termination second output of K switch 1.
The beneficial effects of the utility model are:
1, utilize single-chip to carry out practical function, the fault of whole circuit is less, and the life-span is longer, and cost is lower.
2, this circuit protection performance is splendid; 485 protectors directly realize the protection to chip; the current-limiting function of resistance R13, resistance R14 can prevent the excessive impact to chip of electric current; the high voltage protective function of discharge tube can prevent extraneous high pressure to the impact of chip, and three Transient Suppression Diodes also effectively can offset the impact impacted chip.
3, antijamming capability is strong, and the filter function of multiple inductance and electric capacity, effectively can eliminate clutter, ensures the stability of signal.
4, resistance R16 and K switch 1 is devised, the distance whether regulating terminal to mate by the access of resistance R16.
Accompanying drawing explanation
Fig. 1 is circuit theory diagrams of the present utility model.
Embodiment
485 buffer circuits as shown in Figure 1 comprise chip ADM2587, the RX pin of chip ADM2587 connects RXD bus, the TX pin of chip ADM2587 connects TXD bus, the DE pin of chip ADM2587 connects second pin of inverter 74HC04, first pin of inverter 74HC04 connects RXD bus, 2nd pin of chip ADM2587 is by electric capacity C33 ground connection, 8th pin of chip ADM2587 connects the 2nd pin of chip ADM2587, the 1st of chip ADM2587, 3, 9, 10, 11, 14, 16, the equal ground connection of 20 pin, electric capacity C32, electric capacity C31 is in parallel with electric capacity C33 respectively, 12nd pin of chip ADM2587 is by electric capacity C36 ground connection, 19th pin of chip ADM2587 connects the 12nd pin of chip ADM2587, electric capacity C34, electric capacity C35 is in parallel with electric capacity C36 respectively, 15th pin of chip ADM2587 is by resistance R15 ground connection, 18th pin of chip ADM2587 meets VDD by resistance R12, 13rd pin of chip ADM2587 connects the 18th pin of chip ADM2587, 17th pin of chip ADM2587 connects the 15th pin of chip ADM2587, an input of 485 protectors connects the 18th pin of ADM2587 by resistance R13, and connect the first output by inductance L 4, another input of 485 protectors connects the 15th pin of ADM2587 by resistance R14, and connect the second output by inductance L 5, the earth terminal ground connection of 485 protectors, the negative pole of voltage stabilizing didoe D1 connects the first output, the positive pole of voltage stabilizing didoe D1 connects the negative pole of the second output and voltage stabilizing didoe D2 respectively, the plus earth of voltage stabilizing didoe D2, the negative pole of voltage stabilizing didoe D3 connects the first output, the plus earth of voltage stabilizing didoe D3, the two ends of discharge tube connect the first output and the second output respectively, the earth terminal ground connection of discharge tube, one termination first output of resistance R16, another termination K switch 1 one end of resistance R16, another termination second output of K switch 1, 3rd pin of inverter 74HC04 connects RXD bus, 4th pin of inverter 74HC04 connects LED1 positive pole, LED1 negative pole connecting resistance R17 one end, resistance R17 other end ground connection, 5th pin of inverter 74HC04 connects TXD bus, 6th pin of inverter 74HC04 connects LED2 positive pole, LED2 negative pole connecting resistance R18 one end, resistance R18 other end ground connection, 2nd pin of chip ADM2587 connects 5V voltage vcc, and the 12nd pin of chip ADM2587 meets VDD.
Wherein, devise the current-limiting protection measures such as resistance R13, resistance R14,485 protectors, discharge tube; inductance L 4, inductance L 5 is utilized to eliminate interference; also be provided with Transient Suppression Diode D2, D3, D1 to improve stability; be provided with resistance R16 and K switch 1 at output, reach the adjustable effect of matching distance.
Except structure described in the utility model, all the other are prior art.
The above is preferred implementation of the present utility model; for those skilled in the art; under the prerequisite not departing from the utility model principle, can also make some improvements and modifications, these improvements and modifications are also regarded as protection range of the present utility model.
Claims (2)
1. a buffer circuit, it is characterized in that, comprise chip ADM2587, the RX pin of chip ADM2587 connects RXD bus, the TX pin of chip ADM2587 connects TXD bus, the DE pin of chip ADM2587 connects second pin of inverter 74HC04, first pin of inverter 74HC04 connects RXD bus, 2nd pin of chip ADM2587 is by electric capacity C33 ground connection, 8th pin of chip ADM2587 connects the 2nd pin of chip ADM2587, the 1st of chip ADM2587, 3, 9, 10, 11, 14, 16, the equal ground connection of 20 pin, electric capacity C32, electric capacity C31 is in parallel with electric capacity C33 respectively, 12nd pin of chip ADM2587 is by electric capacity C36 ground connection, 19th pin of chip ADM2587 connects the 12nd pin of chip ADM2587, electric capacity C34, electric capacity C35 is in parallel with electric capacity C36 respectively, 15th pin of chip ADM2587 is by resistance R15 ground connection, 18th pin of chip ADM2587 meets VDD by resistance R12, 13rd pin of chip ADM2587 connects the 18th pin of chip ADM2587, 17th pin of chip ADM2587 connects the 15th pin of chip ADM2587, an input of 485 protectors connects the 18th pin of ADM2587 by resistance R13, and connect the first output by inductance L 4, another input of 485 protectors connects the 15th pin of ADM2587 by resistance R14, and connect the second output by inductance L 5, the earth terminal ground connection of 485 protectors, the negative pole of voltage stabilizing didoe D1 connects the first output, the positive pole of voltage stabilizing didoe D1 connects the negative pole of the second output and voltage stabilizing didoe D2 respectively, the plus earth of voltage stabilizing didoe D2, the negative pole of voltage stabilizing didoe D3 connects the first output, the plus earth of voltage stabilizing didoe D3, the two ends of discharge tube connect the first output and the second output respectively, the earth terminal ground connection of discharge tube, 3rd pin of inverter 74HC04 connects RXD bus, 4th pin of inverter 74HC04 connects LED1 positive pole, LED1 negative pole connecting resistance R17 one end, resistance R17 other end ground connection, 5th pin of inverter 74HC04 connects TXD bus, 6th pin of inverter 74HC04 connects LED2 positive pole, LED2 negative pole connecting resistance R18 one end, resistance R18 other end ground connection, 2nd pin of chip ADM2587 connects 5V voltage vcc, and the 12nd pin of chip ADM2587 meets VDD.
2. a kind of 485 buffer circuits according to claim 1, it is characterized in that, described circuit also comprises resistance R16 and K switch 1, termination first output of resistance R16, another termination K switch 1 one end of resistance R16, another termination second output of K switch 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420831285.9U CN204349965U (en) | 2014-12-25 | 2014-12-25 | A kind of 485 buffer circuits |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420831285.9U CN204349965U (en) | 2014-12-25 | 2014-12-25 | A kind of 485 buffer circuits |
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| Publication Number | Publication Date |
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| CN204349965U true CN204349965U (en) | 2015-05-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420831285.9U Active CN204349965U (en) | 2014-12-25 | 2014-12-25 | A kind of 485 buffer circuits |
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| CN (1) | CN204349965U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104506182A (en) * | 2014-12-25 | 2015-04-08 | 李钢 | 485 isolating circuit |
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2014
- 2014-12-25 CN CN201420831285.9U patent/CN204349965U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104506182A (en) * | 2014-12-25 | 2015-04-08 | 李钢 | 485 isolating circuit |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170330 Address after: 250021 Ji'nan, Central District, Shandong City Road, the southern part of the shop No. 18 Patentee after: Shandong Jinzhou Kerui Energy Technology Co. Ltd. Address before: 250024 Ji'nan City, Central District, Shandong sunshine new road, No. 69 Patentee before: Li Gang |