A kind of surge protective device suitable for outdoor communication line
Technical field
The utility model belongs to lightning-protection engineering field, and in particular to a kind of surge protection suitable for outdoor communication line
Device.
Background technology
The systems such as intelligent electric meter have been widely applied to the field of industry and life.Automatic data logging skill is used in ammeter
Art reads data by COM1, and most of situation uses remote reading mode, and remote reading mode should for ammeter
Not only safe but also saving time and money, realizes that the key of the technology is to ensure that communication line is safe and reliable for.But connection
Open air is commonly exposed to, therefore easily because the reason such as thunderbolt introduces overvoltage.
State Intellectual Property Office of the People's Republic of China discloses a kind of communication line thunder prevention device, Publication No.:
CN203707770U, date of publication are:2014.07.09, the communication line thunder prevention device is provided with firsts and seconds two-stage lightning protection circuit, and one
Level lightning protection circuit realizes that two level lightning protection circuit is realized using TVS anti-thunder tubes using TED485 anti-thunder tubes, wherein, FL TED485
Anti-thunder tube, TS are TVS anti-thunder tubes, and its annexation is:TED485 anti-thunder tube FL1, TED485 anti-thunder tube FL2, TVS anti-thunder tubes
TS1 and TVS anti-thunder tubes TS3 positive pole connects and is grounded, TED485 anti-thunder tube FL1, TVS anti-thunder tube TS1 negative poles and TVS anti-thunder tubes
TS2 positive pole is mutually connected in 485A terminals, TVS anti-thunder tube TS2, TVS anti-thunder tube TS3 and TED485 anti-thunder tubes FL2 negative pole phase
It is connected in 485B terminals;Lightning-protection module only need to be connected on RS-485 terminals by the patent using access RS-485 bus modes in parallel
It is upper, centralized automatic meter-reading terminal called and load-carrying ability are not influenceed, ensure terminal in thunderstorm season safe and stable operation, but
It is that the communication line thunder prevention device anti-electromagnetic interference capability of the patent is not strong, and has much room for improvement in response speed.
Utility model content
The purpose of this utility model is overcome the deficiencies in the prior art, there is provided a kind of wave suitable for outdoor communication line
Protection device, including one-level lightning protection circuit, two level lightning protection circuit and three-level lightning protection circuit are gushed, when being struck by lightning, was sensed
Voltage is introduced by the both ends of connection, and as one-level lightning protection circuit, lightning surge is weakened severely to hundred gas-discharge tube GDT
Volt;Thermistor PPTC is responded in microsecond (μ s) rank in two level lightning protection circuit, and surge current is further suppressed,
And inductor and capacitor bank coordinate into filter circuit and thermistor PPTC, raising two level is prevented while surge current is suppressed
The anti-electromagnetic interference capability on thunder and lightning road;Bridge rectifier carries out rectification to the overvoltage of prime in three-level lightning protection circuit, and prevents
Only Transient Suppression Diode is breakdown, and Transient Suppression Diode is responded in psec (ps) rank, by voltage clamping in 8V
Left and right, and realize the common mode to rear end equipment and differential mode protective effect.Surge protective device of the present utility model is suppressing thunder and lightning
During attack, there is the sufficiently fast response time, and ensure that component itself is excellent, ensure communicating terminal in thunderstorm season
Save safe and stable operation.
To achieve the above object, the technical solution adopted in the utility model is as follows:
A kind of surge protective device suitable for outdoor communication line, including one-level lightning protection circuit, two level lightning protection circuit and
Three-level lightning protection circuit, the one-level lightning protection circuit realize that gas-discharge tube GDT is connected across connection using gas-discharge tube GDT
A terminals and B terminals between, the two level lightning protection circuit include the first thermistor PPTC1, the second thermistor
Connected after PPTC2, the first inductor L1, the second inductor L2, the first inductor L1 and the first thermistor PPTC1 series connection
In the A wiring of connection, it is connected to after the second inductor L2 and the second thermistor PPTC2 series connection in the B wiring of connection,
And first inductor L1 and the second inductor L2 respectively pass through the first capacitor C1 and the second capacitor C2 ground connection;The three-level is prevented
Thunder and lightning route diode and Transient Suppression Diode is formed, and its connected mode is:Four commutation diode connection composition bridge-types are whole
Current circuit, two input terminals of bridge rectifier are connected across between connection A terminals and B terminals;Transient state suppresses two
Pole pipe TVS is connected between two lead-out terminals of bridge rectifier, and Transient Suppression Diode TVS both ends pass through respectively
One commutation diode ground connection.
Preferably, the gas-discharge tube GDT is three-stage ceramic gas-discharge tube, its model 3R097CXA.
Preferably, the first thermistor PPTC1 and the second thermistor PPTC2 is high molecular positive temp temperature-sensitive electricity
Resistance, its model KRG060.
Preferably, the Transient Suppression Diode TVS is bipolarity Transient Suppression Diode, its model SM6T6V8A.
Preferably, the commutation diode is fast recovery diode, from model MURS120T3.
Compared with prior art, the beneficial effects of the utility model are:The utility model includes one-level lightning protection circuit, two level
Lightning protection circuit and three-level lightning protection circuit, when being struck by lightning, induced overvoltage is introduced by the both ends of connection, gas-discharge tube
As one-level lightning protection circuit, lightning surge is weakened severely to hectovolt GDT;Thermistor PPTC is micro- in two level lightning protection circuit
Responded in second (μ s) rank, surge current further suppressed, and inductor and capacitor bank into filter circuit with it is hot
Quick resistance PPTC coordinates, and the anti-electromagnetic interference capability of two level lightning protection circuit is improved while surge current is suppressed;Three-level lightning protection
Bridge rectifier carries out rectification to the overvoltage of prime in circuit, and prevents that Transient Suppression Diode is breakdown, and transient state suppresses
Diode is responded in psec (ps) rank, by voltage clamping in 8V or so, and realizes the common mode and difference to rear end equipment
Mould protective effect.Surge protective device of the present utility model has the sufficiently fast response time during lightening strikes are suppressed,
Anti-electromagnetic interference capability is strong, and ensures that component itself is excellent, ensures communicating terminal in thunderstorm season safe and stable operation.
Brief description of the drawings
Fig. 1 is system block diagram of the present utility model.
Fig. 2 is integrated circuit figure of the present utility model.
Embodiment
The utility model will be further described below in conjunction with the accompanying drawings.
With reference to the accompanying drawings 1 and accompanying drawing 2 shown in, a kind of surge protective device suitable for outdoor communication line, including one-level lightning protection
Circuit, two level lightning protection circuit and three-level lightning protection circuit, the one-level lightning protection circuit is using gas-discharge tube GDT realizations, two level
Lightning protection circuit realizes that three-level lightning protection circuit uses Transient Suppression Diode and bridge rectifier using thermistor and inductor
Realize.
In the present embodiment, gas-discharge tube GDT is three-stage ceramic gas-discharge tube from model 3R097CXA, and gas is put
Fulgurite GDT is connected across between connection A terminals and B terminals, and when lightening strikes occur, induced overvoltage is by connection two
End is introduced, and by gas-discharge tube GDT, overvoltage is weakened severely to hectovolt.
Thermistor PPTC selects model KRG060 high molecular positive temp thermistor, the first inductor L1 and the
It is connected to after one thermistor PPTC1 series connection in the A wiring of connection, the second inductor L2 and the second thermistor PPTC2 strings
Be connected to after connection in the B wiring of connection, and the first inductor L1 and the second inductor L2 respectively by the first capacitor C1 and
Second capacitor C2 is grounded;Thermistor PPTC is responded in microsecond (μ s) rank, and surge current is further suppressed,
And inductor and capacitor bank coordinate into filter circuit and thermistor, two level thunder-lightning is improved while surge current is suppressed
The anti-electromagnetic interference capability on road.
Four commutation diode D1~D4 connections form bridge rectifiers, two input terminals of bridge rectifier across
It is connected between connection A terminals and B terminals;Transient Suppression Diode TVS is connected to two outputs of bridge rectifier
Between terminal, and Transient Suppression Diode TVS both ends are grounded by commutation diode D5, D6 respectively;Transient Suppression Diode
TVS selects model SM6T6V8A bipolarity Transient Suppression Diode, and commutation diode is fast from model MURS120T3
Recovery diode.Bridge rectifier carries out rectification to the overvoltage of prime, and prevents that Transient Suppression Diode TVS is breakdown,
Transient Suppression Diode TVS is responded in psec (ps) rank, by voltage clamping in 8V or so, is realized to rear end equipment
Common mode and differential mode protective effect.
The utility model component is few, simple in construction, cost is low, and anti-electromagnetic interference capability is strong, is suppressing lightening strikes mistake
Cheng Zhong, there is the sufficiently fast response time, anti-electromagnetic interference capability is strong, and ensures that component itself is excellent, ensures communication
Terminal is in thunderstorm season safe and stable operation.
Above-described embodiment is only preferred embodiment of the present utility model, not to the limitation of scope of protection of the utility model,
In every case design principle of the present utility model, and the change for carrying out non-creativeness work on this basis and making are used, all should
Belong within the scope of protection of the utility model.