CN208190247U - A kind of RS232 protection circuit - Google Patents
A kind of RS232 protection circuit Download PDFInfo
- Publication number
- CN208190247U CN208190247U CN201820847708.4U CN201820847708U CN208190247U CN 208190247 U CN208190247 U CN 208190247U CN 201820847708 U CN201820847708 U CN 201820847708U CN 208190247 U CN208190247 U CN 208190247U
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- Prior art keywords
- interface
- connects
- self
- recovery fuse
- transformer
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Abstract
The utility model discloses a kind of RS232 to protect circuit; including RS232 interface chip U1; the RXD Interface Terminal concatenation self-recovery fuse PPTC1 of the RS232 interface chip U1 connects No. 1 interface of transformer T, and the TXD Interface Terminal concatenation self-recovery fuse PPTC2 of RS232 interface chip U1 connects No. 2 interfaces of transformer T.This RS232 protects circuit, carries out poor, common mode by gas-discharge tube GDT and protects, and carries out overvoltage and overcurrent protection by electrostatic protection unit；Self-recovery fuse PPTC1 and self-recovery fuse PPTC2 plays the role of time and current limliting to gas-discharge tube GDT and electrostatic protection unit balance play；The secondary filter circuit of transformer T cooperation can stablize the voltage of output；It is whole to can avoid being damaged by instantaneous large-current, by voltage stabilization size needed for working, guarantee that rear end operating circuit works normally；Resistance R2 and capacitor C4 constitute filter circuit can anti-EFT, that is, electrical fast transient (eft) interference.
Description
Technical field
The utility model relates to communication system technology field, specially a kind of RS232 protects circuit.
Background technique
The full name of RS232 is " SERIAL BINARY DATA between data terminal equipment (DTE) and data communications equipment (DCE)
Fabric Interface technical standard ", it is used as debugging mouth, communication between plates interface and monitoring signal interface, transmission distance on communication apparatus
From shorter, debugging use is more frequent, often the plug of band point, therefore interface will receive voltage, the impact of overcurrent, for upper
Problem is stated, therefore proposes a kind of RS232 protection circuit.
Utility model content
The purpose of this utility model is to provide a kind of RS232 to protect circuit, and having, which can avoid, is struck by lightning or high current
And damage, the advantages of the operation is stable, solve the problems, such as in the prior art vulnerable to overvoltage and over-current shock.
To achieve the above object, the utility model provides the following technical solutions: a kind of RS232 protection circuit, including RS232
The RXD Interface Terminal concatenation self-recovery fuse PPTC1 of interface chip U1, the RS232 interface chip U1 connect the 1 of transformer T
Number interface, the TXD Interface Terminal concatenation self-recovery fuse PPTC2 of RS232 interface chip U1 connect No. 2 interfaces of transformer T,
The GND terminal of RS232 interface chip U1 connects the 232-G Interface Terminal of rear end operating circuit, the end GND of RS232 interface chip U1
Sub- connecting resistance R2 ground connection, the both ends shunt-wound capacitance C4 of resistance R2；The RXD Interface Terminal concatenation transient diode TVS1 meets TXD
Interface Terminal, the output termination gas-discharge tube GDT of self-recovery fuse PPTC1 connect the output end of self-recovery fuse PPTC2,
Gas-discharge tube GDT ground connection；The RXD Interface Terminal meets transient diode TVS2 and connects GND terminal, and TXD Interface Terminal connects transient state
Diode TVS3 connects GND terminal；No. 1 interface connecting resistance R1 and diode D1 of the transformer T connects rear end operating circuit
The input termination capacitor C1 of 232-T Interface Terminal, the both ends shunt-wound capacitance C2 of resistance R1, resistance R1 connects rear end operating circuit
232-T Interface Terminal；No. 3 interfaces of the transformer T connect the 232-R Interface Terminal that diode D2 connects rear end operating circuit, become
No. 4 interface serial capacitance C3 of depressor T connect the output end of diode D2.
Preferably, the transient diode TVS1, transient diode TVS2 and transient diode TVS3 model are according to power supply
Power supply selection, when selection+12V power supply, transient diode TVS1, transient diode TVS2 and transient diode TVS3 selection
SMBJ12CA does not use transient diode TVS1 when baud rate is greater than 9600.
Preferably, the model INT3R090L of the gas-discharge tube GDT.
Preferably, the model SMD1206 of the self-recovery fuse PPTC1 and self-recovery fuse PPTC2.
Compared with prior art, the beneficial effects of the utility model are as follows:
This RS232 protects circuit, carries out poor, common mode by gas-discharge tube GDT and protects, is carried out by electrostatic protection unit
Overvoltage and overcurrent protection；Self-recovery fuse PPTC1 and self-recovery fuse PPTC2 play to gas-discharge tube GDT and
The time of electrostatic protection unit balance play and the effect of current limliting；Capacitor C1 carries out hv filtering, resistance R1, capacitor C2 and two
Pole pipe D1 constitutes secondary filter circuit, stablizes the voltage of output；Entirely through carrying out, poor, common mode is protected and overvoltage is excessively electric
Stream protection can avoid being damaged by instantaneous large-current, and voltage clamp is scheduled on work institute by transformer T and secondary filter circuit
The definite value needed guarantees that rear end operating circuit works normally；Resistance R2 and capacitor C4 constitute filter circuit, can anti-EFT be electricity quickly
The interference of transient pulse train.
Detailed description of the invention
Fig. 1 is the circuit diagram of the utility model.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describe, it is clear that the described embodiments are only a part of the embodiments of the utility model, rather than whole
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are without making creative work
Every other embodiment obtained, fall within the protection scope of the utility model.
Referring to Fig. 1, a kind of RS232 protects circuit, including RS232 interface chip U1, the RXD of RS232 interface chip U1
Interface Terminal concatenation self-recovery fuse PPTC1 connects No. 1 interface of transformer T, the TXD Interface Terminal of RS232 interface chip U1
Concatenation self-recovery fuse PPTC2 meets No. 2 interfaces of transformer T, self-recovery fuse PPTC1 and self-recovery fuse PPTC2
Model SMD1206, the GND terminal of RS232 interface chip U1 connects the 232-G Interface Terminal of rear end operating circuit, and RS232 connects
The GND terminal connecting resistance R2 ground connection of mouth chip U1, the both ends shunt-wound capacitance C4 of resistance R2；RXD Interface Terminal concatenates two pole of transient state
Pipe TVS1 connects TXD Interface Terminal, and the output termination gas-discharge tube GDT of self-recovery fuse PPTC1 connects self-recovery fuse
The output end of PPTC2, gas-discharge tube GDT ground connection, the model INT3R090L of gas-discharge tube GDT；RXD Interface Terminal connects
Transient diode TVS2 connects GND terminal, and TXD Interface Terminal meets transient diode TVS3 and connects GND terminal, wherein transient diode
TVS1, transient diode TVS2 and transient diode TVS3 model are selected according to power supply, when selection+12V power supply, transient state two
Pole pipe TVS1, transient diode TVS2 and transient diode TVS3 select SMBJ12CA, when baud rate is greater than 9600, do not use
Transient diode TVS1；No. 1 interface connecting resistance R1 and diode D1 of transformer T connect the 232-T interface end of rear end operating circuit
Son, the both ends shunt-wound capacitance C2 of resistance R1, the input termination capacitor C1 of resistance R1 connect the 232-T interface end of rear end operating circuit
Son；No. 3 interfaces of transformer T connect the 232-R Interface Terminal that diode D2 connects rear end operating circuit, No. 4 interface strings of transformer T
Connect the output end that capacitor C3 meets diode D2.
The RS232 protects circuit, carries out poor, common mode by gas-discharge tube GDT and protects, transient diode TVS1, transient state
The electrostatic protection unit that diode TVS2 and transient diode TVS3 are constituted carries out overvoltage and excessively electric by electrostatic protection unit
Stream protection；Self-recovery fuse PPTC1 and self-recovery fuse PPTC2 are serially connected in electrostatic protection unit and gas discharge respectively
Between pipe GDT, play the role of the time and current limliting to gas-discharge tube GDT and electrostatic protection unit balance play；Capacitor
C1 carries out hv filtering, and resistance R1, capacitor C2 and diode D1 constitute secondary filter circuit, stablize the voltage of output；It is whole
Body avoids being damaged by instantaneous large-current, passes through transformer T by carrying out poor, common mode protection and overvoltage overcurrent protection
And secondary filter circuit voltage clamp is scheduled on work needed for definite value, guarantee that rear end operating circuit works normally；Resistance R2 and electricity
Hold C4 and constitute filter circuit, is conducive to the anti-EFT i.e. interference of electrical fast transient (eft).
In summary: this RS232 protects circuit, carries out poor, common mode by gas-discharge tube GDT and protects, is protected by electrostatic
It protects unit and carries out overvoltage and overcurrent protection；Self-recovery fuse PPTC1 and self-recovery fuse PPTC2 are played and are put to gas
The effect of the time and current limliting of fulgurite GDT and electrostatic protection unit balance play；Capacitor C1 progress hv filtering, resistance R1,
Capacitor C2 and diode D1 constitutes secondary filter circuit, stablizes the voltage of output；Entirely through carry out poor, common mode protect and
Overvoltage overcurrent protection can avoid being damaged by instantaneous large-current, by transformer T and secondary filter circuit by voltage clamp
Definite value needed for being scheduled on work guarantees that rear end operating circuit works normally；Resistance R2 and capacitor C4 constitutes filter circuit, is conducive to
The interference of anti-EFT, that is, electrical fast transient (eft).
While there has been shown and described that the embodiments of the present invention, for the ordinary skill in the art,
It is understood that these embodiments can be carried out with a variety of variations in the case where not departing from the principles of the present invention and spirit, repaired
Change, replacement and variant, the scope of the utility model is defined by the appended claims and the equivalents thereof.
Claims (4)
1. a kind of RS232 protects circuit, including RS232 interface chip U1, it is characterised in that: the RS232 interface chip U1's
RXD Interface Terminal concatenation self-recovery fuse PPTC1 connects No. 1 interface of transformer T, the TXD interface end of RS232 interface chip U1
Substring connects No. 2 interfaces that self-recovery fuse PPTC2 meets transformer T, and the GND terminal of RS232 interface chip U1 connects rear end work
The 232-G Interface Terminal of circuit, the GND terminal connecting resistance R2 ground connection of RS232 interface chip U1, the both ends shunt-wound capacitance of resistance R2
C4；The RXD Interface Terminal concatenation transient diode TVS1 connects TXD Interface Terminal, the output termination of self-recovery fuse PPTC1
Gas-discharge tube GDT connects the output end of self-recovery fuse PPTC2, gas-discharge tube GDT ground connection；The RXD Interface Terminal connects
Transient diode TVS2 connects GND terminal, and TXD Interface Terminal meets transient diode TVS3 and connects GND terminal；No. 1 of the transformer T
Interface connecting resistance R1 and diode D1 connects the 232-T Interface Terminal of rear end operating circuit, the both ends shunt-wound capacitance C2 of resistance R1, electricity
The input termination capacitor C1 of resistance R1 connects the 232-T Interface Terminal of rear end operating circuit；No. 3 interfaces of the transformer T connect two poles
Pipe D2 connects the 232-R Interface Terminal of rear end operating circuit, and No. 4 interface serial capacitance C3 of transformer T connect the output of diode D2
End.
2. a kind of RS232 according to claim 1 protects circuit, it is characterised in that: the transient diode TVS1, transient state
Diode TVS2 and transient diode TVS3 model are selected according to power supply, when selection+12V power supply, transient diode TVS1,
Transient diode TVS2 and transient diode TVS3 selects SMBJ12CA, when baud rate is greater than 9600, does not use two pole of transient state
Pipe TVS1.
3. a kind of RS232 according to claim 1 protects circuit, it is characterised in that: the model of the gas-discharge tube GDT
For INT3R090L.
4. a kind of RS232 according to claim 1 protects circuit, it is characterised in that: the self-recovery fuse PPTC1 and
The model SMD1206 of self-recovery fuse PPTC2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820847708.4U CN208190247U (en) | 2018-06-01 | 2018-06-01 | A kind of RS232 protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820847708.4U CN208190247U (en) | 2018-06-01 | 2018-06-01 | A kind of RS232 protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN208190247U true CN208190247U (en) | 2018-12-04 |
Family
ID=64427924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820847708.4U Expired - Fee Related CN208190247U (en) | 2018-06-01 | 2018-06-01 | A kind of RS232 protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN208190247U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113467189A (en) * | 2020-03-31 | 2021-10-01 | 北京科益虹源光电技术有限公司 | Signal switching unit of photoetching machine excimer laser |
| CN113471930A (en) * | 2020-03-30 | 2021-10-01 | 中兴通讯股份有限公司 | Interface overcurrent protection circuit |
-
2018
- 2018-06-01 CN CN201820847708.4U patent/CN208190247U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113471930A (en) * | 2020-03-30 | 2021-10-01 | 中兴通讯股份有限公司 | Interface overcurrent protection circuit |
| CN113467189A (en) * | 2020-03-31 | 2021-10-01 | 北京科益虹源光电技术有限公司 | Signal switching unit of photoetching machine excimer laser |
| CN113467189B (en) * | 2020-03-31 | 2023-05-23 | 北京科益虹源光电技术有限公司 | Signal switching unit of lithography machine excimer laser |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20181204 |