KR200375235Y1 - A preventive apparatus against a stroke of lighting and surge for xDSL modem - Google Patents

Abstract

The present invention relates to an apparatus for preventing lightning and surge of an xDSL modem, and in particular, in a known xDSL modem, it is installed between the line coupling part and the filter part to discharge the residual surge and pass through the primary protection part to the filter part. A secondary protection unit for blocking; A voice protection unit installed between the voice filter unit and the TEL port to protect a telephone-side device; An equipotential line may be additionally installed to interconnect the frame ground terminal of the primary and secondary protection parts to the frame ground terminal of the PC main body, but if necessary, the primary protection part may be provided between the primary protection part and the line coupling part. An additional current limiting unit is provided to limit the overcurrent passing through the unit to a constant value.

Therefore, even if a lightning strike or surge enters the xDSL modem utilizing the copper line, it can protect the modem itself and the telephone device as well as completely eliminate the damage of the LAN card on the PC side where the power and communication devices are simultaneously connected. In addition, despite the presence of communication grounding and security grounding on the power supply side, it provides a fundamental method for lightning protection and surge protection for communication devices to realize economic and stable communication environment in any environment, and provides excellent quality data communication environment without disconnection and connection failure. You can enjoy

Description

A preventive apparatus against a stroke of lighting and surge for xDSL modem

The present invention relates to a lightning and surge protection device for an X-DSL (hereinafter referred to as "xDSL") modem, and more particularly, a data communication terminal device applicable to a copper wire-based communication line, in particular a telephone signal and In the xDSL modem that uses data signals, it is designed to prevent the modem itself from being damaged by lightning or surges having a large amount of energy through the communication path.

In particular, the xDSL modem has a protection unit 12 composed of gas discharge tubes (GA1, GA), etc., on the input side of the line-side LINE port 11 to the modem as shown in Figs. The filter unit 14 is formed immediately after the coupling unit 13, and the data signal passing through the filter unit 14 is connected to the PC main body 20 through the coupling transformer 18 and the LAN port 19. The voice signal is transmitted to the main circuit unit 17, and the voice signal is transmitted to the TEL port 16 to which a telephone or the like is connected via the voice filter unit 15.

Here, when the surge is input, the discharge is generated from the protection unit 12. Due to the discharge characteristics of the gas discharge tube, a residual surge of about 1 KV or more remains when the surge is inputted at 4 KV. It is supplied to the voice filter unit 15, which has a direct effect on the deterioration of the capacitors constituting these filter units 14 and 15, and has been a cause of failure of the modem. Often followed.

In practice, many modems are damaged and replaced after a lightning strike.In the case of severe lightning damage, the modem is often damaged and cannot be repaired. After a few days of testing with and without use, it appears to be fine.

When such a modem is installed again in the field, it seems to be no problem right now, but after a few days, the problem appears again as bad.

As a result of the cause analysis, in case of the modem exposed to weaker lightning and surge, a large capacity change was observed in the capacitor applied to the input filter.In the early stage of surge inflow, the capacity increased very much and the capacitor became stable after a few days. And return to the normal capacity value.

In this case, there is no problem in testing the modem, and when it is installed in the field, it is continuously exposed to the low level surge in the field, and the capacity changes again. In this case, the capacity change is extremely sensitive to the level of the surge. Shows a gradual deepening characteristic.

Thereafter, the surge characteristics of the capacitors are further deteriorated. The capacitors continuously exposed to the surges undergo a deterioration of their capacity as opposed to the above and eventually lose their function as a capacitor.

In addition, the voice signal is connected to the TEL port 16 via the voice filter unit 15 from the protection unit 12, where the TEL port 16 is a variety of voice level equipment such as the telephone or fax, telephone modem, cash register, etc. Can be connected.

Nevertheless, the telephone or the like connected to the TEL port 16 has substantially no protection method other than the primary protection.

In addition, there is no path for any surge current other than the LAN cable between the modem connected to the communication line and the personal computer connected to the electric line (hereinafter referred to as "PC"). The low impedance passes through the line and the LAN line (current flow), but the internal impedance is high in the modem and inside the PC, which acts as a resistance to the flow of surge current.

These resistances hinder the flow of surge currents, and the surge currents appear as damages leading to thermal loss or overvoltage discharge at high resistances. This results in damage and damage, leaving traces of discharge on the substrate or components.

On the other hand, the line-side coupling of a modem composed of a transformer provides a very good propagation path for a surge waveform corresponding to 1.25 uS to 50 uS, i.e., 800 KHz to 20 KHz, as specified in IEE 62.41.

In addition, from the standpoint of the PC main body, the power supply of the PC, that is, the SMPS, has an output terminal of 0V line grounded in the case, so the surge from the power source reaches the PC case based on the combined capacity of the SMPS.

The surge passing through the line coupling part of the modem and the surge reaching the case of the modem are based on the configuration of the PC connected with the modem and the LAN cable according to the prior art. It is also physically connected via the LAN card and the LAN port of the modem.

Therefore, if there is a lightning phenomenon in a region due to the characteristics of lightning and surge, it is common that the surge is induced in both the power line and the communication line.

Of course, assuming that a surge of the same potential of the same component flows into both lines, the amount of vertical current due to the point-to-point potential difference and the lateral voltage due to the unbalance of the line and the line is the same, so that the current or voltage of any component flows. There is no damage.

However, it is unlikely to be possible because the configuration, properties and characteristics of the power line or communication line are very difficult to achieve the above conditions, and a lateral voltage occurs between L1-L2 of each communication line or power line, and each L1 The vertical voltage is induced between -G and L2-G, and the difference of potentials induced between the communication line and the power line is large, so that the vertical current by the vertical voltage is formed between them.

In view of this process, since the surge component reached between the modem and the PC is connected via LAN cable, the circuit part of both devices with high impedance is provided with a path of discharge or high voltage surge current flow, so that both devices are burned out. This is a problem that causes.

In addition, voice-grade devices that can be connected to the TEL port also require protective measures, such as the recent rapid spread of information and communication devices such as caller ID (CID) telephones, FAX, and cash registers. Due to the phenomena that are being developed and advanced, there is a need to greatly improve the surge protection function between the modem input terminal and the TEL port.

By the way, it is clearly confirmed at the installation site of xDSL modem that has been spread in recent years that the protection unit adopted in the conventional modem is not a perfect protection measure.

Meanwhile, the general home communication environment will be described briefly as follows.

Grounding is required as a facility to prevent lightning and surge damage in general homes.At this point, a safety ground is required to prevent damage from the power supply side of a device that uses a power source such as a PC, and a communication device such as a modem In Jeongseok, to protect from lightning strikes and surges that flow through the communication lines, the basic point is to provide a facility called a communication ground.

The secure ground and the communication ground provided in this way should be connected to the grounding terminal separately from the device using the power source and the device using the communication signal to discharge the lightning and surge components flowing through any path through the ground to prevent damage to the device. It is.

However, the reality is not so when looking at the grounding environment of households utilizing electricity and communication, particularly in rural and rural areas, small and medium cities, or out-of-urban areas.

In addition, even if the security ground on the premise of damage to the human body is not constructed, most of the places are not constructed, it is because it is difficult to find a house equipped with a separate communication ground.

The present invention has been made to solve such a conventional problem, to provide a fundamental protection against lightning strikes and surges for telecommunication terminal devices, especially xDSL modems utilizing copper lines, In addition to providing protection as well as protection against telephone-class devices, it is especially important to provide lightning protection and surge protection for xDSL modems that can completely eliminate LAN card damage on the PC side where both power and communication devices are simultaneously connected. There is a purpose.

In addition, the present invention provides a fundamental plan for lightning protection and surge protection for communication devices in spite of the presence of a communication ground and a power ground on the power supply side. It is also an object of the present invention to provide a lightning and surge protection device for an xDSL modem that can enjoy a data communication environment.

An aspect of the present invention for achieving the above object, the primary protection unit for protecting the circuit from overvoltage flowing through the communication line connected to the LINE port; A line coupling unit for blocking a direct current component between the primary protection unit and the filter unit and coupling the high frequency data network; A filter unit for separating only high-frequency data signals from various signals transmitted through a communication line and passing them to the modem main circuit unit; A voice filter unit for separating only low-frequency voice level signals from various signals transmitted through a communication line and passing them to the TEL port side; In the xDSL modem consisting of a LAN coupling transformer for transferring various data output from the modem main circuit unit to the LAN card in the PC main body, it is installed between the line coupling unit and the filter unit and discharged through the primary protection unit A secondary protection unit for blocking the remaining residual surge from being transmitted to the filter unit; A voice protection unit installed between the voice filter unit and the TEL port to protect a telephone-side device; It characterized in that the equipotential line is additionally installed to interconnect the frame ground terminal of the primary and secondary protection unit to the frame ground terminal of the PC main body.

If necessary, a current limiting part is provided between the primary protection part and the line coupling part to limit the overcurrent passing through the primary protection part to a predetermined value.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the drawings.

Figure 3 shows a block diagram of the xDSL modem implemented the device of the present invention, Figure 4 shows a block diagram of a state connected to the personal computer xDSL modem implemented the device of the present invention, Figure 5 One embodiment circuit diagram of the device is shown, Figure 6 shows another embodiment circuit diagram of the device of the present invention.

According to the present invention, there is provided a device comprising: a primary protection unit 12 that protects a circuit from overvoltage flowing through communication lines L1 and L2 connected to a LINE port 11; A line coupling unit 13 which blocks a direct current component between the primary protection unit 12 and the filter unit 14 and allows high-frequency data to pass therethrough; A filter unit 14 which separates only high-frequency data signals from various signals transmitted through the communication lines L1 and L2 and passes them to the modem main circuit unit 17; A voice filter unit 15 for separating only a low frequency voice level signal from various signals transmitted through the communication lines L1 and L2 and passing the signal to the TEL port 16 side; In the xDSL modem composed of a LAN coupling transformer 18 for transferring various data output from the modem main circuit unit 17 to the LAN card in the PC main body 20 through the LAN port 21,

A secondary protection part 22 which blocks the residual surge which is discharged through the primary protection part 12 from being transferred to the filter part 14;

A voice protection unit (23) which protects the telephone-side device by cutting off excess energy transmitted to the telephone side between the voice filter unit 15 and the TEL port 16;

The basic feature is that an equipotential line 24 is additionally installed to connect the frame ground terminal FGM of the modem to the frame ground terminal FGP of the PC main body 20.

In addition, the present invention additionally installs a current limiting portion 25 for limiting the overcurrent passing through the primary protection portion 12 to a predetermined value between the primary protection portion 12 and the line coupling portion 13 as necessary. It is characterized by one.

At this time, the primary protection unit 12 has a configuration in which several discharge tubes GA1-GA3 are connected in parallel and in parallel to each other in parallel to the communication lines L1 and L2 as in the related art. 25 may have a configuration in which the resistors R1 and R2 are connected in series on the communication lines L1 and L2 or PTC may be used as the current limiting device. Secondary damage due to the longitudinal current due to the correlation may be concerned. In addition, as a common mode choke, it is possible to implement a current limit function by its own surge resistance while removing the in-phase signal. By selecting an appropriate method among the three methods described above, the application range can be extended.

In addition, the line coupling part 13 is formed as a primary coil in which two capacitors C1 and C2 are connected in series on the communication lines L1 and L2, respectively, and the center point is frame-grounded at the rear end of the capacitor. Condensing (C1, C2) in series in the middle of the primary and secondary coils of the transformer (T1) having a primary and secondary coils to connect or configure the transformer (T1) in two separate as shown in FIG. It has a connected configuration.

In addition, the secondary protection unit 22 may be composed of various semiconductor surge stations as shown in FIG. 5, or may be composed of a bridge diode BD as shown in FIG. 6, and the ground terminal of the secondary protection unit 22 may be configured as shown in FIG. 5. As shown in FIG. 6, the modem directly connects to the frame ground terminal FGM of the modem together with the primary protection unit 12, or to the signal ground terminal SG of the modem as shown in FIG. It has a configuration connected to the terminal (FGM).

In addition, the voice filter unit 15 is composed of a coil (L) connected in series to the tip line (Tip) and the ring line (RING) and a capacitor (C3) connected in parallel between these lines, the voice protection unit ( 23 has a configuration in which three current limiting elements TN1-TN3 are connected directly and in parallel between a tip line Tip and a ring line Ring.

Referring to the operation and effect of the device of the present invention configured as described above are as follows.

First, the primary protection unit 12 connected to the LINE port 11 is connected between both ends of the communication line in the form of a serial connection with one gas discharge tube GA1 connected between both ends of the communication line L1, L2, and the center connection point thereof is It consists of two gas discharge tubes (GA2, GA3) connected to the frame ground terminal (FGM) so that the overvoltage flowing through the communication lines (L1, L2) is discharged through the primary protection unit 12 to lightning the modem And primary protection from surges.

In addition, the line coupling part 13 composed of two DC component blocking capacitors C1 and C2 and a transformer T1 performs a nose pass filter function to block a signal of a voice region that is a low frequency component and to block data of a high frequency component. Only the signal is transmitted to the secondary protection unit 22 and the communication line is coupled to the inside of the modem.

On the other hand, when the lightning and surge flowing through the communication lines (L1, L2) as described above discharged through the primary protection unit 12, the residual components of the overcurrent may remain, if necessary, the primary protection unit Between the 12 and the line coupling portion 13, a current limiting portion 25 having a configuration in which two resistors R1 and R2 are connected in series with respect to the communication lines L1 and L2, respectively.

Therefore, since the overcurrent passing through the primary protection unit 12 is limited to a predetermined value in the current limiting unit 25 and then passed to the line coupling unit 13, the internal circuit of the modem is prevented from being damaged due to the overcurrent. can do.

In addition, the secondary protection unit 22 may be composed of various elements having a voltage limit function or a combination thereof. In this embodiment, the ground terminal may be directly configured as a semiconductor surge device (limit device) as shown in FIG. 5. Directly connected to the frame ground terminal (FGM) or by combining four diodes in the form of a bridge diode (BD) as shown in Figure 6 discharged through the primary protection unit 12, the remaining residual surge to the filter unit 14 Blocked delivery.

Here, the difference from the conventional prior art is the case where the secondary protection part 22 is provided at the rear end of the line coupling part 13, and in the prior art, it is a principle to ground to the signal ground, but in the present invention, FIG. 5 and FIG. As illustrated in FIG. 6, various solutions have been proposed.

That is, when the transformer T1 in the line coupling part 13 is formed of only the primary coil, the ground of the secondary protection part 22 is directly connected to the frame ground terminal FGM. When the secondary and secondary transformers are separated into secondary transformers, the ground of the secondary protection part 22 is directly connected to the signal ground terminal SG and simultaneously connected to the frame ground terminal FGM through the condenser C4. It was.

In addition, as illustrated in FIG. 6, the bridge diode BD may be connected to the secondary protection unit 22. In this case, the input terminal may be connected to both signal lines DT and DR, and the positive output terminal may be connected to the secondary diode. +) Is commonly connected to the power supply terminal Vcc, and the negative output terminal (-) is connected to the signal ground terminal SG and the ground terminal of the primary protection unit 12 through the capacitor C4. May be connected to the frame ground terminal (FGM) connected to the capacitive coupling between the signal ground terminal (SG) and the prime ground terminal (FGM).

At this time, the bridge diode constituting the secondary protection unit 22 can be connected in two ways, the input terminal and the positive output terminal (+) of the common signal line (DT, DR) and the power supply terminal in common. (Vcc), the negative output terminal (-) may be directly connected to the frame ground terminal (FGM) together with the ground terminal of the primary protection unit 12, as shown in Figure 5, the signal ground as shown in FIG. At the same time as the terminal SG, the ground terminal of the primary protection unit 12 is connected to the connected frame ground terminal FGM through the condenser C4 to connect the signal ground terminal SG and the prime ground terminal FGM. Capacitive coupling may also be achieved in the liver.

At this time, the capacity of the capacitor (C4) having a capacitive coupling between the signal ground terminal (SG) and the prime ground terminal (FGM) has a capacity more than the capacity of the capacitor used in general EMI / EMC measures, Only then can it serve as a smooth secondary protection function.

In addition, by installing an equipotential line 24 that can be connected to the frame ground terminal FGP of the PC main body 20, the frame ground terminal FGM connected to the ground terminal of the primary protection unit 12 is connected to the input side. It has excellent protection against lightning and surge while maintaining good equipotential characteristics from the input line to the PC main body 20 without adversely affecting the line such as noise.

That is, equipotential lines 24 are provided between the modem and the frame ground terminal of the PC main body (i.e., FGM-FGP) to ground both frames with an impedance that is much lower than the impedance inside the device through the LAN cable for surge components introduced between the devices. By directly connecting the terminals, damage to the longitudinal current due to the potential difference between devices can be completely eliminated.

On the other hand, the filter unit 14, which is already installed in the xDSL modem, separates only the high frequency data signal from the various signals transmitted through the communication lines L1 and L2 and passes the data signal to the modem main circuit unit 17.

In addition, in the voice filter unit 15 including one or two coils L and a capacitor C3, high frequency components are blocked and only a low frequency voice signal is passed, and three current limiting devices TN1-TN3 are provided. ) And the voice protection unit 23 having a configuration connected in series and parallel between the tip line (Tip) and the ring line (Ring) in the phone side by cutting off the excess energy transmitted to the phone side through the voice filter unit 15 It will protect your device.

The above-described embodiment is described with respect to the most preferred example of the present invention, but is not limited to the above embodiment, it will be apparent to those skilled in the art that various modifications are possible without departing from the spirit of the present invention.

As described above, according to the present invention, by adding a secondary protection part and a voice protection part in the xDSL modem, an equipotential line which is directly connected to the frame ground terminal of the PC main body is installed in the frame ground terminal of the modem. The xDSL modem that utilizes the copper line can protect the modem itself and the telephone device even if lightning and surges flow, as well as completely eliminate the damage of the LAN card on the PC side where the power and communication devices are simultaneously connected.

In addition, despite the presence of communication grounding and security grounding on the power supply side, it provides a fundamental method for lightning protection and surge protection for communication devices to realize economic and stable communication environment in any environment, and provides excellent quality data communication environment without disconnection and connection failure. It is a very useful design, such as to enjoy.

1 is a block diagram of a conventional xDSL modem.

2 is a block diagram of a lightning and surge protection unit of a conventional xDSL modem.

Figure 3 is a block diagram of an xDSL modem is implemented device according to the present invention.

Fig. 4 is a block diagram of a state in which an xDSL modem to which the present invention is implemented is connected to a personal computer.

5 is a circuit diagram of an embodiment of the present invention.

6 is a circuit diagram of another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

11: LINE port 12: Primary protection part

13: line coupling part 14: filter part

15: voice filter unit 16: TEL port

17: modem main circuit 18: LAN coupling transformer

19, 21: LAN port 20: PC body

22: secondary protection unit 23: voice protection unit

24: equipotential line 25: current limiting part

Claims (6)

A primary protection unit that protects the circuit from overvoltage introduced through a communication line connected to the LINE port; A line coupling unit for blocking a direct current component between the primary protection unit and the filter unit and allowing high frequency data to pass through; A filter unit for separating only high-frequency data signals from various signals transmitted through the communication line and passing them to the modem main circuit unit; A voice filter unit for separating only a low frequency voice level signal from various signals transmitted through the communication line and passing the signal to the TEL port; In the xDSL modem consisting of a LAN coupling transformer for transferring various data output from the modem main circuit unit to the LAN card in the PC main body through a LAN port, A secondary protection unit for preventing the residual surges discharged through the primary protection unit from being transferred to the filter unit; A voice protection unit that protects the phone-side device by cutting off the excess energy transmitted to the phone side between the voice filter unit and the TEL port; Lightning of the X-DSL modem, characterized in that an additional equipotential line is installed to directly connect the frame ground terminal (FGM) of the modem to the frame ground terminal (FGP) of the PC main body to prevent damage to the longitudinal current of both devices. Surge protection device. The method according to claim 1, Lightning and surge protection device of the X-SD modem, characterized in that the current limiting unit is further provided between the primary protection unit and the line coupling unit to limit the overcurrent passing through the primary protection unit to a predetermined value. The method according to claim 1, The line coupling unit connects two DC blocking capacitors in series on a communication line and connects a transformer of one coil grounded at an intermediate step to a rear end of the capacitors. Surge protection device. The method according to claim 1, The line coupling unit is configured to connect the capacitors in series to the middle tap portions of the primary and secondary coils of the transformer by winding the primary and secondary coils separately in two, respectively. Prevention device. The method according to claim 1, The grounding terminal of the secondary protection unit is connected to the frame ground terminal (FGM) of the modem together with the primary protection unit lightning and surge protection device of the X-SD modem. The method according to claim 1, The ground terminal of the secondary protection unit is connected to the signal ground terminal (SG) of the modem and simultaneously connected to the frame ground terminal (FGM) of the modem connected to the ground terminal of the primary protection unit through a capacitor. Modem lightning and surge protection.