[DESCRIPTION]

[invention Title]

POWER SUPPLY APPARATUS FOR TELECOMMUNICATION DEVICE HAVING SURGE PROTECTION MODULE

[Technical Field]

The present invention generally relates to an adapter- type power supply apparatus equipped with a surge protection module which supplies a power source to a communication device, and more particularly to an apparatus capable of protecting the power supply apparatus and the communication device from being damaged due to lightning or surge while supplying the power source to the communication device.

[Background Art]

Although a typical power supply apparatus is provided with a surge protection module in an input terminal, there is no method for coping with the surge reverse-flowed from the power supply load circuit. Particularly, in a case of an adapter-type power supply apparatus which is applied to the communication device, the surge reverse- flowed through an output code of the adapter- type power supply apparatus reversely flows a rectifying device to form a discharge path to the power supply side or a

reverse-discharge path opposite to the discharge path due to a property of a load device to which the communication line is connected.

Generally, most adapter- type power supply apparatuses are not equipped with a separate ground and the communication device such as ADSL modem is also operated without connection of the ground .

In regard to such structure, if a potential difference

(surge induction) is generated between a power source line and the communication line is generated, the communication device such as a modem or the adapter-type power supply apparatus may be frequently broken.

Hereinafter, prior power supply apparatus will be briefly described referring to the accompanying drawings. Fig. 1 is a basic drawing of prior power supply apparatus, Fig. 2 is a drawing showing a power supply apparatus according to the switching method, and Fig. 3 is a block diagram corresponding to it. Fig. 4 shows one example of power supply system view of the communication device, in which most communication devices which can be frequently found in living circumference such as a modem for use in internet or a facsimile are utilizing the adapter-type power supply apparatus of such system.

The general communication device such as the modem for use in internet or the facsimile is universally applying the

surge protection method by providing a lightning arrester in an input side of the communication line, and a separate power supply apparatus, i.e., an adapter is universally utilized without having the power supply apparatus built-in within the device .

The power source line for supplying the power source is connected and the communication line is connected in order to cause most electric communication machines to be operated, which results in a surge induction path by way of the power source line and a surge induction path by way of the communication line.

As shown in Fig. 5, the prior surge protection apparatus is provided with a surge protection apparatus of power source unit in a front end of the rectifying device which is a necessary component of the power supply device to release the surge induced via the power source line outside of the machine via the ground line of the power supply unit and also provided with a surge protection apparatus of the communication unit in a front end of the communication device to release the surge induced via the communication line outside of the machine via the ground line of the communication unit (an arrow in Fig. 5 indicates a surge discharge path) .

However, there are no proper countermeasures for the potential difference due to the surge induced via the paths

different from each other in a general structure of prior power supply apparatus mentioned above referring to Fig. 1 to Fig. 5. Particularly, though it is considered to connect an element such as a barrister between the lines as a solution for the surge between the power source lines or between the communication lines, there is no countermeasure for the potential difference generated between the line and the ground or between the power source line and the communication line.

Further, if the surge is induced, there is a problem that can not cope with the surge where the ground to earth is unreliable and floating.

Particularly, even when applying a lightning protector or a surge protector in the power source line side and the communication line side as shown in Fig. 5, satisfactory ground facility must be still equipped in the power source side and the communication side. Even though the ground is equipped, there is a problem that the difference between the power source line and the communication line can not be resolved since most potential difference is applied across the ground resistance if the potential difference between the communication line and the power source line, i.e., the surge is induced, considering that the power source -side ground reference is up to lOOohm and the communication- side ground reference is up to lOohm whereas the internal impedance of the

surge defined by IEC is 2 ohm.

[Disclosure] [Technical Problem] An object of the present invention is to an adapter-type power supply apparatus for communication device equipped with a lightning protection module which can protect a surge by resolving the potential difference between the power source line and the communication line when the surge is induced. Other object of the present invention is to an adapter- type power supply apparatus which does not allow an external surge to be transferred to the rectifying device equipped in the power supply apparatus and the communication device by forming a protection loop from a surge current even when the surge is induced in any path by resolving the potential difference between the power source line and the communication line .

Still other object of the present invention is to provide an adapter-type power supply apparatus for communication device having a protection function from the surge even in non-ground modes including a floating state where the adapter- type power supply apparatus for communication device, the communication device, or the ground of the adapter- type power supply apparatus for communication device and the

communication device are not connected to the earth respectively or a failure state of earth ground connection.

Still other object of the present invention is to provide a lightning protection apparatus for communication device which is capable of protecting the surge by resolving a potential difference between a power source line and a communication line when the surge is induced.

Still other object of the present invention is to provide a lightning protection apparatus for communication device which is capable of protecting the communication circuit and the rectifying device equipped in the communication device from the external surge by forming a protection loop for the surge current even though the surge is induced in any path.

Still other object of the present invention is to provide a lightning protection apparatus of communication device having a protection function from the surge even in non-ground modes including a floating state where the ground of the communication device is not connected to the earth or a failure state of earth ground connection.

[Technical Solution]

To achieve the above objects, the present invention provides an adapter-type power supply apparatus for communication device which supplies a power source (+, -) to a

communication device pre-provided with a surge protection module and protects the communication device from a surge, wherein the power supply apparatus is configured with a power input protection module, a rectifying device connected to a rear end of the power input protection module to rectify an alternating current to a direct current, and an iso-potential module, the power input protection module is configured with a first voltage restriction element which connects two power source lines of the power supply apparatus in parallel and a second and a third voltage restriction elements which are connected in series with each other to connect the two power source lines in parallel, the iso-potential module is configured with a first discharging element which connects a negative output line (-) of two output lines of the rectifying device with a first outgoing line between the second and the third voltage restriction devices composing the power input protection module and has a discharge starting voltage which is 0.5 times to 2 times the maximum voltage of a commercial power voltage, and the iso-potential module is electrically connected to the communication line via the negative output line (-) of the two output lines of the power supply apparatus and the surge protection module pre-provided in the communication device when the surge is induced so that a discharge path is formed between the two power source lines of

the power supply apparatus and the two communication lines of the communication device.

The adapter-type power supply apparatus for communication device according to the present invention can protect the surge by forming the iso-potential between the power source line and the communication line to resolve the potential difference between the power source line and the communication line.

The first outgoing line and one side of the first discharging element connected with the first outgoing line are connected are connected to a ground line.

At this time, the ground terminal which is an external outgoing terminal of the ground line is connected to the earth or in a floating state where it is open without connection to the earth.

The power supply apparatus further comprises a power output protection module and the power output protection module further comprises a voltage restriction element connecting two output lines of the rectifying device in parallel.

The discharge starting voltage of the discharging element composing the iso-voltage module is 0.5 times to 2 times the maximum voltage of a commercial power voltage.

Since the discharge path is formed between the power

source line and the communication line when the surge is induced by the iso-potential module, a noise is caused in the communication line if the discharge starting voltage of the discharging element composing the iso-potential module is less than 0.5 times and the discharge of the discharging element is not performed even though the potential difference between the power source line and the communication line is generated by substantial induction of surge if the it is more than 2 times.

Preferably, the power input protection module, the rectifying device and the iso-potential module are integrally equipped in a single case.

Typically, the communication device such as internet modem and facsimile is equipped with communication- side surge protection device in order to protect the surge induced via the communication line as shown in Fig. 5. The communication- side surge protection device is configured with the discharging element for the purpose of high speed data communication and the communication line and the internal ground of the communication device is connected with each other by the discharging element, and the internal ground of the communication device is connected to a negative power source of the power source supplied to the communication device .

Therefore, when connecting the adapter-type power supply

apparatus for communication device via the code in order to supply the power source to the communication device, it is connected to the internal ground of the communication device, the surge protection device of the communication device and the communication line via the power source lines, the power input protection module for protecting the surge between the power source lines, the iso-potential module.

Herein, the first to third voltage restriction elements or the voltage restriction element equipped in the power output protection module are a barrister, a discharging element (GCA element) provided with a discharging control electrode or a gas-filled discharging tube.

The GCA element includes a air-tight cylinder formed with ceramic insulating material, a pair of discharging electrodes disposed oppositely in end opening of the air-tight cylinder, a discharging gap formed between the pair of discharging electrodes, discharging-aid material filled inside the airtight cylinder and a discharge control electrode which is in contact with the ceramic insulating material and physically separated from the discharging-aid material. The GCA element is a discharging element in which discharge is induced between the pair of discharging electrodes by the control voltage applied via the discharging control electrode, and specifically a discharging element in which a metal material

of metal line and metal film is tightly adhered in a line or a surface to the ceramic insulating material forming an external surface of the air-tight cylinder. The discharging element provided with the discharging control electrode is specifically disclosed in Korean Patent Application No. 2007- 0086390.

Herein, if the communication- side surge protection device is not provided, the communication input protection module can be structured in input side of two communication lines Ll, L2 of the communication device.

The communication input protection module includes a second and a third discharging element which is connected in series with each other to connect the two communication lines Ll, L2 in parallel, a second outgoing line between the second and the third discharging element is connected to a negative output line (-) of the rectifying device by electric connection of the communication device with the adapter-type power supply apparatus and thus to the first discharging element . Preferably, the communication input protection module further comprises a discharging element which connects two communication lines Ll, L2 in parallel.

Herein, if the ground terminal exists in the communication device, the internal ground line of the

communication device outgoing from the external ground terminal is preferably connected to the second outgoing lien.

The ground terminal of the external outgoing terminal of the internal ground line of the communication device may be connected to the earth and in a floating state where it is open without connection to the earth.

A lightning protection apparatus of communication device according to the present invention comprises a power input protection module connected to two power source lines, a rectifying device connected to a rear end of the power input protection module to rectify an alternating current to a direct current, a communication circuit connected to an output of the rectifying device, a communication input protection module connected to two communication lines for protecting the communication circuit from a surge, and an iso-potential module, wherein the power input protection module comprises a first voltage restriction element connecting the two power source lines in parallel and a second and a third voltage restriction element connected in series with each other to connect the two power source lines in parallel; the iso- potential module comprises a first discharging element which connects a negative output line (-) of the two output lines of the rectifying device with a first outgoing line between the second and the third voltage restriction element composing the

power input protection module; the communication input protection module comprises a second and a third discharging elements connected in series with each other to connect the two communication lines in parallel; and the iso-potential module is electrically connected to the communication line via the negative output line (-) of the two output lines of the power supply apparatus and the communication input protection module when the surge is induced to form a discharge path between the two power source lines and the two communication lines.

Preferably, the lightning protection apparatus of the communication device can be provided with an internal ground line and a ground terminal of an external output terminal of the internal ground line, and the internal ground line is connected to any one side of two sides of the iso-potential module .

At this time, the ground terminal may not be connected to the earth or may in an open state of unstable connection.

At this time, the ground terminal may be connected to the earth.

The discharge starting voltage of the discharging element composing the iso-voltage module is 0.5 times to 2 times the maximum voltage of a commercial power voltage to cause the surge to be efficiently discharged while preventing the noise

induced to the communication line.

Preferably, a second outgoing line between the second and the third discharging element is connected to the negative output line (-) of the rectifying device and thus to the iso- potential module.

Preferably, the communication input protection module further comprises a discharging element connecting two communication lines Ll, L2 in parallel.

Preferably, the power input protection module, the rectifying device, the communication circuit, the communication input protection module and the iso-potential module are integrally equipped in a single case.

[Advantageous Effects] The adapter- type power supply apparatus for communication device according to the present invention has advantages in that it can protect the surge by resolving the potential difference between the power source line and the communication line only by electric connection with the communication device via the code when the surge is induced, effectively protect the rectifying device and the communication device from an external surge by forming the protection loop from the surge current even when the surge is induced in any path, and have a protection function from the surge even in non-ground modes

including a floating state where the ground of the adapter- type power supply apparatus and the communication device is not connected to the earth or a failure state of earth ground connection.

[Description of Drawings]

The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:

Fig. 1 is a basic circuit diagram of prior power supply apparatus ;

Fig. 2 is a basic circuit diagram of prior switching-type power supply apparatus; Fig. 3 is a block diagram of prior switching- type power supply apparatus;

Fig. 4 is a power supply concept diagram for prior electric communication device;

Fig. 5 is a surge protection concept diagram for prior electric communication device;

Fig. 6 is a block diagram showing an adapter- type power supply apparatus for communication device according to one example of the present invention;

Fig. 7 is a circuit diagram showing an adapter-type power

supply apparatus for communication device according to one example of the present invention;

Fig. 8 is a circuit diagram showing an adapter-type power supply apparatus for communication device according to another example of the present invention;

Fig. 9 is a optic photography showing an adapter- type power supply apparatus for communication device integrally manufactured in a case according to the present invention;

Fig. 10 is one block diagram showing the surge protection apparatus of the communication device according to the present invention;

Fig. 11 is one circuit diagram showing the surge protection apparatus of the communication device according to the present invention.

[Detailed Description of Main Elements]

100: adapter-type power supply apparatus

200: communication device

110 : power input protection module 120: rectifying device

130: iso-potential module

140: power supply output protection module

210: communication circuit

220: communication input protection module

300: surge protection device

^■ [Best Mode]

Hereinafter, an adapter-type power supply apparatus according to the present invention will be described in detail with reference to accompanying drawings. The accompanying drawings are provided as an example sufficiently to deliver an idea of the present invention to the person skilled in the art.

Therefore, the present invention is not bounded by the drawings presented hereinafter but can be specified in another form. Further, like reference numerals denote like element throughout the following detailed description of the invention.

At this time, if the technological terms and science terms used herein do not have any other definition, they have meanings that can be typically understood hy the person skilled in the art. Further, known functions and structures which can unnecessary make obscure the subject matter of the present invention in the following description and accompanying drawings will be omitted. Further, though the communication device pre-equipped with a typical surge protection module is electrically connected to the adapter-type power supply apparatus for communication device according to the present invention, a surge protection effect can be achieved via the present

invention. Therefore, it will be described based on the adapter-type power supply apparatus for communication device according to the present invention.

Fig. 6 is a block diagram showing a structure of an adapter- type power supply apparatus for communication device according to the present invention.

The power supply apparatus for communication device 100 according to the present invention provides the power source

( + , -) to the communication device 200 via the code and includes a power input protection module 110, a rectifying device 120 connected to a rear end of the power input protection module 110 to rectify an alternating current input through a power input terminal 141, 142 and output a direct current, and an iso-potential module 130. The power supply apparatus 100 can be integrally equipped in a single case and is preferably an adapter-type power supply apparatus.

Therefore, the direct current output via the rectifying apparatus 120 is electrically connected 143, 144 to the communication device 200 via a code (not shown) equipped in the power supply apparatus .

The communication device 200 is typically configured with a communication circuit 210 composed according to a kind of the communication device and a communication input protection module 220 connected to two communication lines 231, 232, in

which the communication device 200 can be integrally equipped in a single case. Herein, the power supply apparatus 100 and the communication device 200 can be equipped with ground terminals 145, 233 respectively. As the communication circuit 210 is protected by the surge protection module of the present invention, as a communication circuit or a communication module used for the general electric communication device, to restrict a structure and a kind thereof is meaningless but it can be a communication circuit used for a modem for use in internet and a facsimile.

The communication input protection module 220 has typically small internal capacity and thus is configured using a discharging element which makes possible high speed data communication, and the communication line is typically connected to a negative power source line of the communication device by the discharging element, and the negative power source line of the communication device is connected to an internal ground of the communication device when the internal ground is equipped in the communication device.

As the rectifying device 120 is also protected by the lightning protection module of the present invention similarly to the communication circuit 210, to restrict a structure or a kind thereof is meaningless and any device of rectifying the

alternating current to direct current is available.

As shown in Fig. 6, the communication device 200 is electrically connected 143, 144 with the adapter-type power supply apparatus 100 so that it is electrically connected to the negative output line (-) of the rectifying device 120 and thus to the iso-potential module 130. That is, it is possible to cause the power input protection module 110 within the adapter-type power supply apparatus 100, the communication line within the communication device 200, the ground and the communication input protection module 210 pre-equipped in the communication device 200 to be connected naturally while providing the power to the protected communication device 200, via a code line (not shown) which is connected to the communication device 200 as an output of the adapter-type power supply apparatus 100.

Referring to Fig. 6, it is appreciated that the structure except for the communication device 200 is one example of the adapter-type power supply device for communication device according to the present invention and the present invention can be applied without regard to the structure of the communication circuit 210 or the communication input protection module 220 composing the communication device 200 of Fig. 6. That is, the device such as internet modem mentioned as one example of the communication device is

necessarily equipped with the surge protection device for protecting the lightning surge in the input unit to which the communication line is connected. Since the surge protection device equipped in the typical communication device is electrically connected to the ground line within the communication device, when any communication device is electrically connected to the adapter-type power supply apparatus for communication device, the internal ground line of the protection module which is provided in the adapter-type power supply apparatus for communication device to prevent over-voltage/current due to lightning or surge is connected to the ground within the communication device, i.e., the DC power source (-) line via the code of the power supply apparatus and thus to the ground terminal of the communication device. Therefore, the lightning surge protection method can be implemented by providing the discharge path which can resolve the potential difference between the power source line and the communication line.

The rectifying device 120 is equipped within the adapter- type power supply apparatus 100, in which the power input protection module 110 is provided in an input side of the rectifying device 120 and the power output protection module (140 in Fig. 8) is selectively provided in an output side of the rectifying device 120 (selectively provided if a length of

the code is long considering a length of the power supply code) . The iso-potential module 130 is further provided, in which the protection modules 120, 130, 140 are connected to the communication device 200 from the adapter- type power supply apparatus 100 and thus to (-) power source line of the communication device 200, i.e., ground terminal via the code (not shown) supplying the power.

Referring to Fig. 6, each module provided in the adapter- type power supply apparatus 100 is connected to the communication device 200 via the output line, i.e., the code of the adapter- type power supply apparatus 100 in one path of the power input protection module 110 - the rectifying device 120 (or power input protection module 110 - the rectifying device 120 - the power output protection module 140) and other path of the power input protection module 110 - the iso- potential module 130 (or the power input protection module 110 the iso-potential module 130 - power output protection module 140) .

The communication device 200 has a unique communication circuit 210 to perform its own function, in which the communication circuit 210 has a self-surge protection element provided in the input terminal connected to the communication line. Since one side of the self -surge protection element is connected to the (-) power source line and the ground line

input via the code even when the communication circuit 210 is provided with the self -surge protection element, the idea of the present invention can be realized without whether the self -surge protection element is provided or not. Since the communication device 200 is provided with the communication input protection module 220 between the communication circuit 210 and the communication line, the communication line can be protected from the surge .

Arrows shown in Fig. 6 (b) indicate discharge paths in a case where a voltage difference is generated due to the surge induced between the power source line and the communication line, in which the route of lightning surge are formed in a direction of the power input terminals 141, 142 - the adapter- type power supply apparatus 100 provided with surge protection function - an output power code (not shown) of the adapter- type power supply apparatus 100 - communication input protection module 220 - the communication input terminals 231, 232 or in an inverse direction thereof.

Herein, the route of the power input protection module 110 - the rectifying device 120 (or power input protection module 110 - the rectifying device 120 - the power output protection module 140) causes the surge induced from the power source line, i.e., the input side to be removed and the direct current rectified by the rectifying device RECT is further

protected by the power output protection module 140 if the power output protection module 140 is provided.

Further, the surge induced from the communication line is protected by the communication input protection module 220 provided in the communication device and connected to the ground terminal of the communication device 200. Since the ground terminal is connected to the negative terminal (-) of the output code of the adapter-type power supply apparatus 100, the discharge path Li of the surge is formed by way of the iso-potential module 130 provided in the adapter-type power supply apparatus 100 via the power code even if the ground terminal is unstably connected to the earth or is not connected to the earth.

Thereby, the surge induced via the power source line is removed by the power input protection module 110 and the surge induced via the communication line is removed by the communication input protection module 220, each of the protection modules 110, 140, 220 of the power supply apparatus 100 and the communication device 200 is connected to each internal ground via the iso-potential module 130.

A current damage caused by lightning surge includes a potential difference caused due to imbalance between the lines, i.e., "crosswise current" damage and a potential difference occurred between the line (communication line) and other line

(power source line) or between the points, i.e., "lengthwise current" damage.

In a case of the potential difference between the power source line and the communication line, i.e., "crosswise current" , it is possible to effectively provide a discharging route for the potential difference between the power source line and the communication line while resolving the potential difference between the lines of each of the power source lines and the communication lines, by forming the discharge path of the communication input protection module 220 pre-provided in the communication device - the internal ground line of the communication device 200 - the power output code of the adapter-type power supply apparatus 100 - iso-potential module 130 - the power input protection module 110. Therefore, the communication circuit 210 can be perfectly protected from lightning surge induced via any route.

Since the discharge path is formed with respect to the surge between the communication lines or the power source lines, and as well as the potential difference, i.e., surge induction between the communication line and the power source line, the communication device can be sufficiently protected using the ground terminals FG, SG connected to the ground facility in a case which the ground is equipped in the power source side and communication side and via the above-mentioned

discharge path even in a non-ground case which there is no ground facility.

Fig. 7 is a circuit diagram showing one block diagram of Fig. 6 in a circuit state. At this time, the communication input protection module 210 shown in Fig. 7 is a circuit example of the communication input protection module 210 most basically equipped in the communication device. Though such circuit is configured of discharging elements 211, 212 which are connected in series to each other to cause two communication lines to be connected in parallel, a suppressing element can be used instead of the discharging element.

Figs. 7 (a) to 7(c) show each example which is different depending on whether the ground line is provided or not. When the ground terminal connected to the earth is not provided in the communication device 200 and the power supply apparatus 100 as described in Fig. 6 or the earth connection is unstable even when it is provided, the surge can be protected by causing the communication line and the power source line to be iso-potential between the communication line and the power source line, the surge is suppressed by the power input protection module 110 between the power source lines, and the surge is suppressed by the communication input protection module 210 between the communication lines, as shown by the arrows in Fig. 7 (a) . Therefore, the surge can be protected

even when the ground is not provided as such in Fig. 7 (a) or all ground are in a floating state, the surge can be protected even when the ground FG connected to the earth is provided in only power supply apparatus such as in Fig. 7 (b) , and also the surge can be protected even when the grounds FG, SG connected to the earth are provided in each of the power supply apparatus and the communication device as in Fig. 7(c) . The ground lines FG, SG in Fig. 7 (a) to Fig. 7 (c) refer to a ground facility which pre-exists outside of the apparatus or a ground line which is connected to the earth, in which the circuit diagram of Fig. 7 (a) is not equipped with the ground terminals 145, 232 of Fig. 6 and has similar structure as the floating sate where the ground terminals 145, 232 are open if the internal ground line is formed as in Fig. 6. Since Fig. 7 (a) to Fig. 7 (c) have the same structure except for the ground line, one circuit diagram according to the present invention will be described referring to Fig. 7 (b) .

As shown in Fig. 7 (b) , the power input protection module

100 according to the present invention is configured with a first voltage constraint element Zl, 111 connecting in parallel two power source lines L, N of the power supply apparatus and a second and a third voltage restriction element Z2, Z3 , 112, 113 which are connected in series with each other to cause the two power source line L, N to be connected in

parallel. The iso-potential module 130 is configured with a first discharging element 131 which connects a negative output line (-) of two output lines of the rectifying apparatus 120 with a first outgoing line between the second and third voltage restriction elements 112 and 113 composing the power input protection module 110.

The power input protection module 110 is provided in an input side where the power source line L-N is connected to the rectifying device 120, and protects 111 between the power source lines and protects 112, 113 each of the power source lines using the voltage restriction elements.

The communication input protection module 220 is provided in the input side where the communication line L1-L2 is connected to the communication circuit 210 to protect 221, 222 each of the communication lines.

The iso-potential module 130 is configured with a first discharging element 131 which connects a negative output line

(-) of two outputs lines of the rectifying device 120 with the first outgoing line between the second and third voltage restriction elements 112, 113 composing the power input protection module 110.

At this time, the discharge starting voltage of the first discharging element 131 has a value which is at least 0.5 times the maximum voltage of commercial power voltage, whereby

it can prevent a noise due to commercial frequency component of the power source line in the communication device. The discharge starting voltage of the first discharging element 131 is preferably 0.5 times to 2 times the maximum voltage of the commercial supply voltage, and more preferably 1.1 times to 2 times, in order to prevent the surge from being induced and suppress the noise.

By electrically connecting the DC output voltage supply (DC output ( +) , DC output (-)) to the communication device 200 via the code ( + , -), the discharge path due to a property of a load device to which the communication line is connected for the communication circuit 210 is formed by way of the power source lines (L, N) - the power input protection module 110 - the iso-potential module 130 - the code - the ground line of the communication device 200 (meaning the ground line if the ground line SG is structured as in Fig. 7 (c) , and the negative power source line if it is structured in an open state as in Figs. 7 (a) and 7 (b) ) - the communication input protection module 220 - the communication lines Ll, L2 , in which it is characterized in having the discharge paths between the power source line and the communication line, between the power source line and the ground, between the communication line and the ground, and between different grounds.

Specifically, if the potential difference due to the

lightning surge is generated between the power source lines L, N and the communication lines Ll, L2, the discharge path is formed by way of the power source lines L, N - the second voltage restriction element and the third voltage restriction element 112, 113 - the first discharging element 131 - the negative power source line (DC output (-)) of output power code (not shown) of power supply apparatus 100 - the second discharging element and the third discharging elements 221, 222 - the communication lines Ll, L2 so that the internal circuit within the communication device 200 may be restricted up to a protection level, whereby it is possible to prevent a damage from lightning and surge even when the grounds SG and FG are not connected to the earth ground.

Fig. 8 shows a circuit diagram of anther example which further comprises a power output protection module 140, in which the communication input protection module 200 further comprises a discharging element 223 connecting two communication lines Ll, L2 in parallel.

If the surge is induced between the power source lines L- N, it is discharged and eliminated by way of the discharge route of one power source line L - the first voltage restriction element - other power source line N, whereby the communication device 200 including the rectifying device 120 can be protected.

Further, if the lightning surge is induced between the communication lines Ll - L2, it is discharged and eliminated by way of the discharge route of one communication line L - the first voltage restriction element - other power source line N, whereby the communication device 200 including the rectifying device 120 can be protected.

Fig. 9 is a drawing showing the adapter-type power supply apparatus for communication device housed within an integral case according to the present invention. As described above referring to Fig. 6 to Fig. 8, even though the potential difference between the power ground FG and the communication ground SG is 5,000V when considering that the power source lines L, N are applied with a surge of 6,000V and the communication ground line SG is applied with a surge of 1,0000V, the modem can be protected at a level of protection level (700V) of the power input protection module 110 + a protection level (200V) of the iso-potential module 130 + a protection level (200V) of the communication input protection module 220 =l,100V (DC) . It can allow the modem to be sufficiently protected even when considering an enduring standard for 1 minute at AC 1,500V at the time of a certification of the typical communication device (for example, ADSL modem) .

Referring to Fig. 6 to Fig. 8, even though the adapter-

type power supply apparatus has been described in which the communication input protection module generally used for the communication device is physically separated from the communication device to supply the power source to the communication device, the iso-potential module which is a main component of the present invention and the protection effect of the iso-potential module can be also achieved in the communication device in which the rectifying circuit is pre- provided. Fig. 10 is one block diagram of the integrated surge protection apparatus 300 for communication device in which the power supply apparatus is physically not separated from the communication device.

The surge protection apparatus 300 according to the present invention is configured with the power input protection module 110, the rectifying device 120 connected to a rear end of the power input protection module 110 to rectify the alternating current input via the power input terminals 141, 142 to the direct current, the communication circuit 210 connected to the output of the rectifying device, the communication input protection module 220 connected to two communication lines 231, 232, and the iso-potential module 130.

The surge protection device 300 according to the present invention can be integrally equipped in a single case. At this

time, the ground terminal 145 may be unstably connected to the earth or in an open state which is not connected to the earth.

Fig. 11 is one circuit diagram of the surge protection device 300 according to the present invention. The surge protection device 300 according to the present invention is configured with the first voltage constraint element Zl, 111 connecting two power source lines L, N in parallel and the second and the third voltage restriction elements Z2, Z3, 112, 113 which are connected in series with each other to cause the two power source lines L, N to be connected in parallel, at a front end of the rectifying device 120. The rectifying device 120 rectifies the alternating current input via two power source lines to the direct current and the output of the rectifying device 120 is connected to the communication circuit 210.

The iso-potential module 130 is configured with a first discharging element 131 which connects a negative output line (-) of two output lines of the rectifying apparatus 120 with the first outgoing line between the second and third voltage restriction elements 112 and 113 composing the power input protection module 110. The communication input protection module 220 connected to the two communication lines Ll, L2 is configured with a second and a third discharging elements 221, 222 connected in series with each other to connect the two

communication lines Ll, L2 in parallel and the second outgoing line between the second and the third discharging elements 221, 222 is connected to the negative output line (-) of the rectifying device 120 and connected to the first discharging element 131.

The power input protection module 110 is equipped in the input side where the power source line L-N is connected to the rectifying device 120, and protects 111 between the power source lines and protects 112, 113 each of the power source lines using the voltage restriction elements. The communication input protection module 220 is provided in the input side where the communication lines L1-L2 are connected to the communication circuit 210 and protects 221 222 each of the communication lines. The surge protection apparatus in Fig. 10 and Fig. 11 has the same structure as that of the adapter-type power supply apparatus for communication device mentioned above, except that the module for supplying the power and the module for performing a unique function of the communication device are not physically separated from each other but connected with each other. Therefore, components which are the same as those of Fig. 6 to Fig. 8 are denoted as the same reference numerals, in which the same reference numerals are responsible for taking the same roles as those described above referring to

Fig . 6 to Fig . 8 .

Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.