CN104506182A - 485 isolating circuit - Google Patents
485 isolating circuit Download PDFInfo
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- CN104506182A CN104506182A CN201410814756.XA CN201410814756A CN104506182A CN 104506182 A CN104506182 A CN 104506182A CN 201410814756 A CN201410814756 A CN 201410814756A CN 104506182 A CN104506182 A CN 104506182A
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Abstract
The invention discloses a 485 isolating circuit. The 485 isolating circuit is configured with a filtering capacitor and a communication indication circuit, a 485 protector, a discharging tube, current limiting resistors R13 and R15 and transient inhibition diodes D1, D2 and D3 are designed at the output end of a chip ADM2587 to protect the chip, and inductors L4 and L5 are utilized to eliminate interference. Due to the fact that a single chip is utilized to realize functions and protection measures are added, the whole circuit has few failures and is longer in service life and lower in cost.
Description
Technical field
The present invention 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.
Summary of the invention
In order to solve the above problems, the invention provides a kind of 485 buffer circuits, not only solve the problem that cost is high, protective is poor, and there is the adjustable function of terminal distance matching distance.
The present invention 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 invention has the beneficial effects as follows:
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 invention.
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 of the present invention, all the other are prior art.
The above is the preferred embodiment of the present invention, and for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications are also regarded as protection scope of the present invention.
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 |
|---|---|---|---|
| CN201410814756.XA CN104506182A (en) | 2014-12-25 | 2014-12-25 | 485 isolating circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410814756.XA CN104506182A (en) | 2014-12-25 | 2014-12-25 | 485 isolating circuit |
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| Publication Number | Publication Date |
|---|---|
| CN104506182A true CN104506182A (en) | 2015-04-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410814756.XA Pending CN104506182A (en) | 2014-12-25 | 2014-12-25 | 485 isolating circuit |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112180813A (en) * | 2020-10-22 | 2021-01-05 | 湖南中车时代通信信号有限公司 | Hard wire synchronous processing device and control system |
Citations (4)
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| CN103269126A (en) * | 2013-05-10 | 2013-08-28 | 杭州电子科技大学 | Intelligent low-voltage molded case circuit breaker controller based on Ethernet communication |
| CN203720290U (en) * | 2014-03-11 | 2014-07-16 | 中国电子科技集团公司第三十八研究所 | Single-phase electrical parameter fast acquisition module |
| CN203798509U (en) * | 2014-04-30 | 2014-08-27 | 西安科技大学 | Sulfur hexafluoride gas leakage monitoring alarm device |
| CN204349965U (en) * | 2014-12-25 | 2015-05-20 | 李钢 | A kind of 485 buffer circuits |
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2014
- 2014-12-25 CN CN201410814756.XA patent/CN104506182A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103269126A (en) * | 2013-05-10 | 2013-08-28 | 杭州电子科技大学 | Intelligent low-voltage molded case circuit breaker controller based on Ethernet communication |
| CN203720290U (en) * | 2014-03-11 | 2014-07-16 | 中国电子科技集团公司第三十八研究所 | Single-phase electrical parameter fast acquisition module |
| CN203798509U (en) * | 2014-04-30 | 2014-08-27 | 西安科技大学 | Sulfur hexafluoride gas leakage monitoring alarm device |
| CN204349965U (en) * | 2014-12-25 | 2015-05-20 | 李钢 | A kind of 485 buffer circuits |
Non-Patent Citations (2)
| Title |
|---|
| PHOEBER012: "通讯接口RS485的电磁兼容设计方案", 《HTTP://WENKU.BAIDU.COM/LINK?URL=Y38WMM04SYPVVQIMT0I9J5WOSZMCE5M0FZAR8KETO5NTRLV-5NV0LFZQWAUZJTPLIMOAXSVLSGIJFGQWML96DMQZWDI0FBEW2RUDZTUG9IQ》 * |
| 北京晶圆智通科技有限公司: "浅谈ADM2587E在RS485/422接口隔离中的应用", 《单片机与嵌入式系统应用》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112180813A (en) * | 2020-10-22 | 2021-01-05 | 湖南中车时代通信信号有限公司 | Hard wire synchronous processing device and control system |
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Application publication date: 20150408 |
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| WD01 | Invention patent application deemed withdrawn after publication |