CN2629350Y - Physical isolating apparatus between local area network and internet - Google Patents

Abstract

The utility model provides a physical isolation device of a local area network and the Internet. An isolating circuit is arranged on a connecting line that connects a computer, the local area network and the Internet. The isolating circuit is provided with a trigger M, which is provided with a trigger end M3 and a trigger end M4. The trigger end M3 and the trigger end M4 are connected with a positive electrode of a power supply G. Two output ends triggered by the trigger end M3 and the trigger end M4 in the trigger are connected respectively with switching circuits of two isolating circuits. The utility model realizes the control of the switching circuit through the function of the trigger, and realizes the control of two isolating circuits that are mutually breakovered and cut off through the switching circuit. The utility model not only realizes the physical isolation of the local area network and the Internet, but also realizes the isolation that only needs to operate an isolation button or a resume button instead of pulling out or inserting the connecting wire, thereby making the isolation safe and convenient, and overcoming the shortages of ineffectness and trouble that exist in the prior art.

Description

The physical isolation apparatus of local area network (LAN) and internet

Technical field the utility model relates to the physical isolation apparatus of a kind of local area network (LAN) and internet, especially a kind ofly is used to make and can inserts the computer realization local area network (LAN) of the Internet and the physically-isolated device between the internet with non-dialing login mode.

The physical isolation apparatus of background technology local area network (LAN) and internet, a kind of effective measures as the protection LAN information safety are widely used.The patent No. is that the Chinese patent " spacer assembly of local area network (LAN) and internet " of ZL02208268.9 has proposed a kind ofly local area network (LAN) and internet to be carried out physically-isolated device when being used for the local area network (LAN) computer and entering the Internet with the dialing login mode: " signal comparator circuit is arranged; signal input part and the modulator-demodulator of computer in local area network (LAN) are connected with telephone wire between the telephone network; on the connecting line of this computer and local area network (LAN) buffer circuit is installed, the control switch circuit of buffer circuit is connected with the instruction output end of signal comparator circuit." from its technical scheme as seen, the work of this spacer assembly must excite with the signal of telecommunication in when dialing, and for the computer that need not dial and can enter the Internet, this spacer assembly is just inoperative.For this reason, people have to with the grid line terminal between local area network (LAN) and internet back and forth plug realize isolating but hell to pay.

Summary of the invention is at above-mentioned defective, the technical problems to be solved in the utility model is how to avoid making with the computer realization local area network (LAN) of non-dialing login mode access the Internet and the isolation between the internet with the method for plug network terminal, and proposes the physical isolation apparatus of a kind of local area network (LAN) and internet.

The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, on the connecting line between computer and the local area network (LAN), buffer circuit is installed, also has the connecting line between a computer and the internet, another buffer circuit has been installed on the connecting line between this computer and the internet, one trigger M is arranged again in addition, have two trigger end M3, M4 to be connected with the positive pole of power supply G through two button SB1, SB2 respectively in the trigger end of this trigger, two outputs that triggered by trigger end M3, M4 connect the switching circuit of two buffer circuits respectively.Wherein alleged buffer circuit is the various devices that make connecting and disconnecting of the circuit, as the contact of relay, automatic switch etc.The state that buffer circuit is set here is for often leaving.The switching circuit of the buffer circuit of installing on the connecting line between the output of trigger M and computer and the local area network (LAN) is connected, the button that trigger end connected that triggers this output is a recovery button, even computer recovers multiple button to the state that is connected with local area network (LAN).And the switching circuit of the buffer circuit of installing on the connecting line between the output of trigger M and computer and the internet is connected, the button that trigger end connected that triggers this output is for isolating button, though computer be in local area network (LAN) between the button that is connected the state that is cut off and is connected with the internet.The connecting line of connecting line between computer and the local area network (LAN) and computer and internet, the end that they are connected with computer can be an end, that is to say that these two lines can be by the grid line of three terminals that link in the Y mode, be that the three pass network line replaces, these three terminals connect computer, local area network (LAN) and internet respectively, and two buffer circuits are respectively between point of contact and the terminal that is connected local area network (LAN) and between point of contact and the terminal that is connected the internet.

The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, said buffer circuit are the normally opened contacts of relay, and the active line bag of relay is connected on the power supply through switching circuit.The buffer circuit of being installed on the connecting line between computer and the local area network (LAN) is the normally opened contact K0 of a relay, the switching circuit at the active line bag J1 place of this relay is connected with the output of trigger M, and this output is that the trigger end that is subjected to be connected with recovery button triggers; And the buffer circuit of being installed on the connecting line between computer and the internet is the normally opened contact K2 of another relay, the switching circuit of the active line bag J2 of this relay is connected with another output of trigger M, and this output is to be subjected to and to isolate the trigger end that button is connected and trigger.When relay active line bag J1 works, make normally opened contact K0 closure, thereby make connecting line path between computer and the local area network (LAN) and being connected of conducting computer and local area network (LAN) then makes computer and being connected of local area network (LAN) be cut off when this relay is not worked.Relay active line bag J2 work the time makes normally opened contact K2 closure, thereby makes connecting line path between computer and the internet and being connected of conducting computer and internet, and computer and being connected of internet are cut off.

The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, said switching circuit is a switching tube, the trigger electrode of switching tube is connected with the output of trigger M.The switching circuit of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN) is a switching tube VT1, and its trigger electrode is connected with the output of trigger M, and this output is that the trigger end that is subjected to be connected with recovery button triggers; The switching circuit of the buffer circuit of being installed on the connecting line between computer and the internet also is a switching tube VT2, and its trigger electrode is connected with another output of trigger M, and this output is to be subjected to and to isolate the trigger end that button is connected and trigger.

The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, as more rational design, between the output of the switching circuit of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN) and trigger M, an inverter I is installed again, and simultaneously buffer circuit is arranged to normally off.Like this, when recovery button after the trigger end of trigger M sends triggering signal, because of the effect of inverter makes the switching circuit of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN) can not receive triggering signal, and when isolating button after the trigger end of trigger M sends triggering signal, because of the effect of trigger and inverter makes the switching circuit of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN) receive triggering signal, switching circuit work also starts buffer circuit and makes it transfer open-circuit condition to.Therefore this setting can make wherein operating time shortening of switching circuit and the working life that reduces power consumption and prolong circuit, because the time that is connected in the local area network (LAN) of computer is more much longer than the time that is connected in the internet.

The physical isolation apparatus of local area network (LAN) provided by the utility model and internet, also has a signal comparator circuit A, the signal input part A1 of signal comparator circuit A and the dialing modem of computer are connected with connecting line L between the telephone network, and the instruction output end A4 of signal comparator circuit is connected between the switching circuit and inverter I of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN).When computer through dialing modem when internet Sending dialled number semaphore request connects, signal comparator circuit can send instruction and make being connected between the buffer circuit work cut-out computer installed on the connecting line of computer and local area network (LAN) and the local area network (LAN) to switching circuit.No matter computer is to login the internet with non-dial mode or with dial mode like this, the local area network (LAN) that the utility model provides and the physical isolation apparatus of internet can both play the physics of local area network (LAN) and internet every effect.

The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, designed the circuit that to select one at computer and local area network (LAN) UNICOM or computer and internet UNICOM this two states, promptly rely on the effect of trigger, realization is to the control of switching circuit, and realizes control to two buffer circuit conductings each other or cut-out through switching circuit.The effect of trigger is: have only when trigger end is given a triggering signal, the pairing output of this trigger end just can be exported high level, and other outputs then must be output low levels; But after another trigger end is accepted triggering signal, then originally triggered and the output of exporting high level just changes output low level into, the output that is triggered after simultaneously changes the output high level into.When selecting to change the on off operating mode of a switching circuit by button, another switching circuit also can change on off operating mode simultaneously like this.The local area network (LAN) that the utility model provides and the physical isolation apparatus of internet, both realized the physical isolation of local area network (LAN) and internet, and need realize isolating needing only again by the mode of dialling slotting connecting line by just passable to the operation of isolating button or recovery button.Especially the operation of isolating button or recovery button be select one, under normal circumstances are essential operations, i.e. the operation that desire enters the Internet or access to LAN all must pass through button could realize.So the local area network (LAN) that the utility model provides and the physical isolation apparatus of internet are effective and easy.

Description of drawings Fig. 1 is the circuit diagram of the utility model one embodiment;

Fig. 2 is the circuit diagram of another embodiment of the utility model.

Embodiment embodiment one: a three pass network line is arranged, three line ends connect the RJ45 terminal by standard respectively, one of them RJ45 terminal RJ45.1 is connected on the network interface card in the computer, a RJ45 terminal RJ45.2 is connected on the hub of local area network (LAN), and a RJ45 terminal RJ45.3 is connected on the ADSL Modem.Other has a circuit board that is installed in the shell, various electronic components are installed on the circuit board, their title and annexation are: it is the 8D trigger M of 74LS374 that a model is arranged, 3,4 bipod M3, M4 are connected on the positive pole of power supply G through two button SB1, SB2 respectively, and the working power input M0 of trigger M is connected with the both positive and negative polarity of power supply G respectively with earth terminal M10.The 2 pin M2 that triggered by trigger 3 pin M3 are connected on the trigger electrode (base stage) of a switching tube VT1, and all the other the two poles of the earth of switching tube VT1 (emitter, collector electrode) is connected on the positive pole of power supply G and is connected on the negative pole of power supply G through a relay active line bag J1, a resistance R 3 respectively; The 5 pin M5 that triggered by trigger 4 pin M4 are connected through a resistance R 6 on the trigger electrode (base stage) of a switching tube VT2, and all the other the two poles of the earth of switching tube VT2 (emitter, collector electrode) is connected on the negative pole of power supply G and through a relay active line bag J2 and is connected on the positive pole of power supply G.One group of normally opened contact K0 that active line bag J1 is connected the relay on the emitter of switching tube VT1 is connected three pass network line point of contact and is connected between the RJ45 terminal RJ45.2 on the hub of local area network (LAN).The button SB1 that is connected on 3 pin of trigger M is a recovery button.One group of normally opened contact K2 that active line bag J2 is connected the relay on the collector electrode of switching tube VT2 is connected three pass network line point of contact and is connected between the RJ45 terminal RJ45.3 on the ADSL Modem.Be connected button SB2 on 4 pin of trigger M for isolating button.Foregoing circuit as shown in Figure 1, the point of contact of three pass network line is located on the contact of relay, the local area network (LAN) that present embodiment provides and the initial state of the physical isolation apparatus of internet are that computer neither is connected also with local area network (LAN) and is not connected with the internet.

Embodiment two: a three pass network line is arranged, three line ends connect the RJ45 terminal by standard respectively, one of them RJ45 terminal RJ45.1 is connected on the network interface card in the computer, a RJ45 terminal RJ45.2 is connected on the hub of local area network (LAN), and a RJ45 terminal RJ45.3 is connected on the ADSL Modem.Other has a circuit board that is installed in the shell, various electronic components are installed on the circuit board, their title and annexation are: have two inputs of a bridge circuit AB to insert respectively on the dialing modem of computer and the line L between the telephone network, two resistance R 4, R5 series connection back and a capacitor C and being connected between two outputs of bridge circuit connects, on the signal input part A1 of the voltage comparator A that to draw a lead access model between these two resistance be LM339.It is 9 volts power supply G that one output voltage is arranged, and is in series with two resistance R 1, R2 between its both positive and negative polarity, draws the reference voltage input A2 that a lead inserts voltage comparator A between these two resistance.The working power input A0 of voltage comparator links to each other with the positive pole of power supply G, and earth terminal A3 links to each other with the output negative pole of bridge circuit AB and links to each other with the negative pole of power supply G.The trigger electrode (base stage) of the instruction output end A4 of voltage comparator A and switching tube VT1 with link to each other.Also having a model is the 8D trigger M of 74LS374, and 3,4 bipod M3, M4 are connected on the positive pole of power supply G through two button SB1, SB2 respectively, and the working power input M0 of trigger M is connected with the both positive and negative polarity of power supply G respectively with earth terminal M10.The 2 pin M2 that triggered by trigger 3 pin M3 are connected on the trigger electrode (base stage) of switching tube VT1 behind 7402 the inverter, and all the other the two poles of the earth of switching tube VT1 (emitter, collector electrode) is connected on the positive pole of power supply G and is connected on the negative pole of power supply G through a relay active line bag J1, a resistance R 3 respectively; The 5 pin M5 that triggered by trigger 4 pin M4 are connected through a resistance R 6 on the trigger electrode (base stage) of a switching tube VT2, and all the other the two poles of the earth of switching tube VT2 (emitter, collector electrode) is connected on the negative pole of power supply G and through a relay active line bag J2 and is connected on the positive pole of power supply G.One group of normally-closed contact K1 that active line bag J1 is connected the relay on the emitter of switching tube VT1 is connected three pass network line point of contact and is connected between the RJ45 terminal RJ45.2 on the hub of local area network (LAN).The button SB1 that is connected on 3 pin of trigger M is a recovery button.One group of normally opened contact K2 that active line bag J2 is connected the relay on the collector electrode of switching tube VT2 is connected three pass network line point of contact and is connected between the RJ45 terminal RJ45.3 on the ADSL Modem.Be connected button SB2 on 4 pin of trigger M for isolating button.Foregoing circuit as shown in Figure 2, the point of contact of three pass network line is located on the contact of relay, the local area network (LAN) that present embodiment provides and the initial state of the physical isolation apparatus of internet are that computer is connected with local area network (LAN) but is not connected with the internet.

Claims (5)

1, the physical isolation apparatus of a kind of local area network (LAN) and internet, on the connecting line between computer and the local area network (LAN), buffer circuit is installed, it is characterized in that also having the connecting line between a computer and the internet, another buffer circuit has been installed on the connecting line between this computer and the internet, one trigger [M] is arranged again in addition, two trigger ends [M3] are arranged in the trigger end of this trigger, [M4] is respectively through two buttons [SB1], [SB2] is connected with the positive pole of power supply [G], be subjected to trigger end [M3] in this trigger, two outputs that [M4] triggers connect the switching circuit of two buffer circuits respectively, and buffer circuit is set to normally open.

2, the physical isolation apparatus of local area network (LAN) as claimed in claim 1 and internet is characterized in that said buffer circuit is the normally opened contact of relay, and the active line bag of relay is connected on the power supply through switching circuit.

3, the physical isolation apparatus of local area network (LAN) as claimed in claim 1 or 2 and internet is characterized in that said switching circuit is a switching tube, and the trigger electrode of switching tube is connected with the output of trigger [M].

4, the physical isolation apparatus of local area network (LAN) as claimed in claim 1 or 2 and internet, it is characterized in that between the output of the switching circuit of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN) and trigger [M], an inverter [I] being installed again, and simultaneously buffer circuit is arranged to normally off.

5, the physical isolation apparatus of local area network (LAN) as claimed in claim 4 and internet, it is characterized in that a signal comparator circuit [A] in addition, the signal input part [A1] of signal comparator circuit [A] and the dialing modem of computer are connected with connecting line [L] between the telephone network, and the instruction output end of signal comparator circuit [A4] is connected between the switching circuit and inverter [I] of the buffer circuit of being installed on the connecting line between computer and the local area network (LAN).