JPH1032055A - Overvoltage protection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify an assembly structure and enhance productivity of an overvoltage protection device containing a silicon two-way, two terminal thyrister for absorbing overvoltage in a plug fixed to a receptacle. SOLUTION: A recess 11d is formed in the intermediate part of a plug main body forming the main body of a plug 10, and one end is used as a plug part 11a and the other end is as a holding part 11c of a cable or a receptacle part. A terminal of a silicon two-way, two terminal thyrister 20 is brought into contact with the intermediate part of a pair of electrode wiring bodies 12 arranged in the recess 11d, the thyrister 20 is housed in the recess 11d, they are fixed with a cover 13 closing the recess 11d, then an electrode chip 14 is fit to a contact connecting part 12b of each electrode wiring body 12 to form a contact part with the receptacle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overvoltage protection device capable of simplifying and effectively protecting various communication devices and data processing devices from overvoltage applied via a communication line due to induced lightning or the like. In particular, the present invention relates to an overvoltage protection device having a structure excellent in mass productivity which simplifies the assembly structure.

[0002]

2. Related Background Art In recent years, the development of information communication technology via communication lines has been remarkable, and, for example, network services for exchanging information between a plurality of personal computers via public telephone lines have become widespread. This type of communication line (for example, a public telephone line) is led into a business or home through a protector, and is connected to a personal or
It is connected to a data processing device such as a computer. Especially recently, modular type connectors (modular plug and modular outlet) have become widespread, and the modular plug of the signal cable extended from the data processing device is attached to the modular outlet connected to the indoor wiring. It has become possible to easily connect a data processing device (the same applies to a telephone, a facsimile device, a data communication modem, etc.) to a communication line.

[0003] By the way, communication lines such as public telephone lines are laid not only in urban spaces but also in a plurality of cities and vertically and horizontally and widely. For this reason, an excessive voltage due to induced lightning is often applied to the communication line in an area where lightning occurs, and an excessive current (surge current) may flow through the communication line due to this. The surge voltage caused by such induced lightning causes damage to data processing devices and the like connected to the communication line and causes data destruction.

[0004]

Therefore, conventionally, for example, an overvoltage protection circuit is incorporated in a protector provided at the entrance of a communication line in an office or a home to absorb the surge voltage and protect the data processing device. Ingenuity is given. This overvoltage protection circuit is generally constructed by interposing a surge protection element such as a lightning arrester (gas tube arrester) or a zinc oxide varistor between a pair of communication lines (signal lines) forming the communication line. Is done.
Incidentally, the gas tube arrester and the zinc oxide varistor may be interposed in two stages, and a diode bridge circuit may be inserted in the subsequent stage (multistage protection).

However, the characteristics of gas tube arresters and zinc oxide varistors change with time due to repeatedly applied impulse current. In addition, maintenance and inspection of the protector in which this kind of overvoltage protection circuit is incorporated is entrusted to a qualified technician, and the user cannot perform maintenance and improvement without permission. It is very rare that the above-mentioned overvoltage protection circuit is incorporated in the data processing device. Therefore, even though the surge voltage caused by the induced lightning may have an adverse effect on the data processing device, the user cannot take any measures.

Accordingly, the present inventors have previously described Japanese Patent Application No. 8-114.
No. 971 proposes an overvoltage protection device having a structure in which a silicon two-way two-terminal thyristor for absorbing overvoltage applied from the outside via the outlet is incorporated in a plug body detachably attached to the outlet. The present invention relates to an overvoltage protection device having a structure in which such a silicon two-way two-terminal thyristor is incorporated in a plug body, and in particular, to provide an overvoltage protection device having a structure excellent in mass productivity which simplifies its assembly structure. It is intended to be.

[0007]

In order to achieve the above object, an overvoltage protection device according to the present invention is detachably mounted on an outlet and electrically connected to the outlet, and a plug incorporated in the plug. To absorb overvoltage applied from outside through the outlet.
And a terminal thyristor.
In the invention described in (1), (a1) one end side is a plug portion that can be attached to the outlet, the other end side is a holding portion of a lead wire, and the silicon two-way two-terminal thyristor is an intermediate portion thereof. A plug body formed with a recess for housing,
(b1) one end is an electrical connection portion with a lead wire held by the holding portion, and the other end is a contact connection portion extended to the plug portion, which is disposed along the bottom of the recess and is intermediate A pair of electrode wiring bodies whose parts are in contact with the terminal parts of the silicon two-way two-terminal thyristor; and (c) the terminal parts housed in the recesses and contact the contact parts of the respective electrode wiring bodies. A lid for fixing and holding the silicon two-way two-terminal thyristor closed to close the recess, and (d) being provided so as to be fitted to a contact connection part extended to the plug part of each of the electrode wiring bodies. And an electrode tip fixedly held by the plug body and forming a connection contact with an electrode of the outlet.

According to a second aspect of the present invention, there is provided a relay adapter, wherein the plug comprises: (a2) a plug portion having one end mounted on the outlet, and an outlet portion mounted with another plug on the other end. A plug body having a structure and a concave portion for accommodating the silicon two-way two-terminal thyristor at an intermediate portion thereof; (b2) one end extending to the electrode in the outlet portion, and the other end extending to the plug portion. (C) a pair of electrode wiring bodies disposed along the bottom of the concave portion and having an intermediate portion as a contact portion with a terminal portion of the silicon two-way two-terminal thyristor; A lid closed and closed to hold the silicon two-way two-terminal thyristor in which the terminal portion is housed and in which the terminal portion is in contact with the contact portion of each of the electrode wiring bodies, and (d) Into the plug Provided by fitting each of the junction connection portions, is characterized in that the fixed holding the plug body is constituted by the electrode tip forming a connection contact between the electrodes of the outlet.

That is, the present invention relates to a plug having a built-in silicon two-way two-terminal thyristor, a plug body having a recess formed in an intermediate portion thereof, and a pair of electrode wiring bodies provided in the recess of the plug body. A lid body for fixing and holding the silicon two-way two-terminal thyristor and closing the recess;
2. A plug body attached to an end of a lead wire according to claim 1, wherein the electrode body is constituted by an electrode chip fitted to a contact connection part of each electrode wiring body. In addition, the present invention is characterized in that the assembling structure is simplified even when the relay adapter structure is formed as described in claim 2.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an overvoltage protection device according to an embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 2 is a sectional view showing a schematic configuration of a modular plug constituting the overvoltage protection device, and FIG. 2 is an exploded perspective view showing an assembled structure thereof. In the figure, reference numeral 10 denotes a modular plug, and reference numeral 20 denotes a silicon two-way two-terminal thyristor built in the plug 10.

As will be described below, the plug 10 comprises a plug main body 11 which forms a main part thereof, an electrode wiring body 12, a lid 13 and an electrode chip 14 which are assembled to the plug main body 11, and has therein an inside. The silicon two-way two-terminal thyristor 20 is incorporated and integrated. First, the plug body 1 which forms the main part of the flag 10
For example, the plug body 11 made of, for example, a synthetic resin made of polycarbonate is generally in the shape of a rectangular parallelepiped, and one end of the plug body 11 is a modular plug part 11a having a shape conforming to the FCC standard. I have. The plug portion 11a is detachably attached to a pair of modular outlets (not shown).

On the upper surface side of the plug body 11, a lever 11b having a front end as a hinge is integrally provided. When the lever 11b is elastically displaced downward (upper side of the main body portion) through the hinge portion, the plug 10 is not hindered by shoulders (not shown) formed on both sides of the intermediate portion thereof. (Plug portion 11a) can be attached to and detached from a modular outlet. Also lever 11
b serves to prevent the detachment by engaging the shoulder with the recess formed in the wall surface of the upper space of the modular outlet when it is elastically restored upward while being attached to the modular outlet.

On the other hand, the other end of the plug body 11 forms a holding portion 11c for holding the lead wire 30. The holding portion 11c has an opening into which the end of the lead wire 30 is inserted, and a core through which the core wire 32 from which the sheath 31 of the lead wire 30 inserted into the opening is peeled is inserted into the inside of the plug body 11. It has a wire insertion hole, and has a structure in which a lead wire 30 inserted into the opening is pressed and held by plastic deformation of a pressure-bonding portion forming a part of a wall surface of the opening.

As described above, the intermediate portion of the plug body 11 having the plug portion 11a at one end (front) and the holding portion 11c at the other end (rear) has an opening on the lower surface and the silicon A recess 11d for accommodating the two-way two-terminal thyristor 20 is formed. After the electrode wiring body 12 is provided along the bottom surface of the recess 11d, the silicon two-way two-terminal thyristor 20 is housed. Then, the cover 13 is fitted into the opening of the silicon two-way two-terminal thyristor 20 housed in the recess 11 d and joined and integrated, and the thyristor 20 is inserted into the recess 11 d by the cover 13. To be held and fixed.

Here, the electrode wiring body 12 will be described. Each of the pair of electrode wiring bodies 12 is formed of a conductive metal plate.
It has a shape that is bent in a U-shape so as to be arranged along the inner wall and bottom surface of the concave portion 11d from the side of 1c over the plug portion 11a. One end of the hook-shaped electrode wiring body 12 positioned on the side of the holding portion 11c of the plug body 11 is formed in a U-shape toward the depth of the concave portion 11d, and is held by the holding portion 11c. Lead wire 3
0 constitutes an electrical connection 12a. In particular, the tip of the electrode wiring body 12 which forms the electrical connection portion 12a has Y
When the electrode wiring body 12 is fitted into the recess 11d, the lead wire 30 previously inserted into the core wire insertion hole and disposed in the recess 11d is provided. Is sandwiched from both sides by the cut. With the electric connection portion 12a having such a structure, when the electrode wiring body 12 is fitted into the recess 11d, the electric connection between the electric connection portion 12a and the core 32 is completed.

On the other hand, the other end of the hook-shaped extension of the electrode wiring body 12 extending toward the plug portion 11a is formed by folding over a predetermined length. The folded portion is set as a contact connecting portion 12b having a spring property for mounting the electrode chip 14 as described later. In addition, intermediate portions of the pair of electrode wiring bodies 12 disposed along the bottom surface of the concave portion 11d are formed so as to be wide toward the outside, respectively, and are provided with terminal portions 21 of the silicon two-way two-terminal thyristor 20. Is set as the contact portion 12c.

Thus, the electrode wiring body 12 having the above configuration
Are positioned along a plurality of contact grooves formed from the lower portion on the front side of the plug portion 11a to the bottom portion thereof, and are disposed in the recess 11d of the plug body 11. The fitting of the electrode wiring body 12 into the concave portion 11d is performed in a state where the lead wire 30 is mounted on the holding portion 11c, and as described above, the core wire 32 of the lead wire 30 is fitted.
This is performed while making an electrical connection with the device. Thereafter, the silicon two-way two-terminal thyristor 20 is placed in the recess 11d.
And the terminal portion 21 is brought into contact with the contact portion 12c of the electrode wiring body 12 to be electrically connected. As a result, the silicon 2 is short-circuited between the pair of electrode wiring bodies 12.
A directional two-terminal thyristor 20 is connected.

In this state, the cover 13 is fitted into the opening of the recess 11d so as to cover the silicon two-way two-terminal thyristor 20, and the silicon two-way two-terminal thyristor 20 is positioned by the cover 13. Then, the lid 13 is joined and integrated with the plug body 11. In addition, this lid 13 is
A step for forming a space for disposing the electrical connection portion 12a between the recess and the recess 11d, for positioning and fixing and holding the thyristor 20, and for forming a space on the opposite side surface in which the electrode tip 14 can be disposed. It has a shape. By fixing and integrating the lid 13 having such a shape to the plug body 11, the silicon two-way two-terminal thyristor 20 is pressed toward the electrode wiring body 12, and the terminal portion 21 and the electrode wiring body 12 are The thyristor 20 and the electrode wiring body 12 are positioned and firmly held and fixed in the recesses 11d, respectively, while ensuring stable contact with the contact portion 12c.

Thereafter, the electrode chip 14 is inserted along the contact groove from the lower surface side of the plug portion 11a of the plug body 11, and the electrode chip 14 is fitted to the contact connection portion 12b of the electrode wiring body 12. Let it. The electrode chip 14 is formed of a concave metal piece having a thickness substantially equal to the electrode width of the outlet, and the upper end concave portion 14a is a fitting portion for sandwiching the contact connecting portion 12b of the electrode wiring body 12, and A lower end portion 14b having a bottom corner portion in an arc shape is used as a connection end surface with the electrode of the outlet.
An engaging portion 14c for engaging with the plug body 11 is formed on the side of the electrode tip 14 so as to protrude therefrom.
When the plug 4a is fitted into the contact connecting portion 12b and inserted into the plug portion 11a, the engaging portion 14c is engaged with a groove formed on the inner wall or the like of the plug portion 11a, so that the extraction is prevented. ing. In other words, the electrode chip 14 provided by fitting the upper end concave portion 14a to the contact connecting portion 12b of the electrode wiring body 12 simultaneously engages the engaging portion 14c with the plug portion 11a so as to be irremovably held and fixed. It has become.

The plug 10 having such a structure and accommodating the silicon two-way two-terminal thyristor 20 therein.
According to the method, after the electrode wiring body 12 is provided in the concave portion 11d while the lead wire 30 is held in the holding portion 11c,
1d, a silicon two-way two-terminal thyristor 20 is assembled, the lid 13 is joined to and integrated with the plug main body 11 so as to cover the thyristor 20, and then the electrode chip 14 is assembled to the plug portion 11a. And electrical connection can be completed. In addition, mechanical and structural contact and
Due to the engagement structure, the lead wire 30 and the electrode chip 14, and furthermore, the silicon two-way two-terminal thyristor 20 can be electrically reliably connected via the electrode wiring body 12.

The electrode wiring body 1 is connected to the plug body 11.
The thyristor 20 is positioned and held by the lid 13 in the recess 11d in a state where the electrode tip 2 and the electrode tip 14 are stably positioned via the above-described contact groove, and the lead wire 30 is further connected to the holding portion 11c and the core wire insertion hole. Thus, these electrical connections are made in a state where they are stably positioned and held, so that the structure can be made very strong.

The silicon two-way two-terminal thyristor 20 built in the plug 10 will be briefly described. The silicon two-way two-terminal thyristor 20 is, for example, surface-mounted as shown in FIGS. It has a packaged or button packaged shape. The embodiment described above shows an example in which the thyristor 20 packaged in a surface mount package is used. Reference numeral 21 denotes a terminal portion 21 of the silicon two-way two-terminal thyristor 20.

This silicon two-way two-terminal thyristor 2
Numeral 0 denotes a composite thyristor having a planar type five-layer structure (there is also a four-layer structure) having an element structure as shown in FIG. 4 (a), equivalently as shown in FIG. 4 (b). It is composed of a composite element in which two thyristors are connected in parallel in opposite directions, and basically has a VI characteristic as shown in FIG. That is,
When the applied voltage V is low, the thyristor 20 keeps the junction J2 in reverse bias and keeps the off state (region A). When the applied voltage V approaches the breakdown voltage VB of the junction J2, avalanche breakdown occurs, and the thyristor 20 breaks down. When a voltage exceeding VBO is applied, a current i2 is generated immediately below the P1 layer (region B). Then, a voltage drop (i2.times.R2) caused by the current i2 is applied to the junction J2, and when the voltage drop reaches the diffusion potential VB1 of the junction J2, the N2 is removed from the P1 layer.
Injection of carriers into the layer starts and current i1 flows (region C). As a result, the sum of the current amplification factor α1 of the transistor formed of the N2-P3-N4 layer having current dependency and the current amplification factor α2 of the transistor formed of the P1-N2-P3 layer becomes [1], and the thyristor 20 Is turned on. Then, the thyristor 20 in the ON state generates the ON voltage VT according to the forward voltage drop VF of the PN junction diode (region D). Such an action occurs in accordance with the polarity of the voltage applied to the thyristor 20, and therefore exhibits a bipolar (bidirectional) symmetric VI characteristic as shown in FIG.

Therefore, the silicon 2 having such characteristics
According to the plug in which the directional two-terminal thyristor 20 is incorporated as described above, as shown in FIG. 6, the front stage (the line connection by the plug) of the protected circuit (data processing device) connected to the signal line having the predetermined load RL. That is, the thyristor 20 is interposed in the section (1). Then, as shown in FIG. 7, during a normal operation in which a predetermined voltage VB is applied to the line, the thyristor 20 does not conduct as a result, so that the line current iL is supplied to the protected circuit as it is. However, when an excessive surge voltage Vsurge due to induced lightning or the like is applied to the line, when the voltage exceeds the breakover voltage VBO, the thyristor 20
Are instantaneously conducted, and the surge current isurge is bypassed through the thyristor 20. At this time, thyristor 20
, Only the ON voltage VT is generated at both ends thereof, so that the above-mentioned excessive surge voltage Vsurge is not applied to the protected circuit. The thyristor 20 is turned off when the surge current isurge gradually decreases and becomes equal to or less than the holding current IH of the thyristor 20, so that the operation mode shifts to the normal operation mode described above.

Therefore, as described above, according to the present device in which the silicon two-way two-terminal thyristor 20 is incorporated in the modular plug 10, even if the surge voltage Vsurge from the communication line caused by the induced lightning is applied, the silicon two-way two-terminal thyristor 20 is provided. The instantaneous conduction of the two-terminal thyristor 20 causes the surge voltage Vsu
rge-dependent surge current Isurge is quickly bypassed, and the voltage applied to the signal cable 30 is reduced by the thyristor 20
(On voltage VT). As a result, the surge voltage Vsurge is cut off by the modular plug 10 and the data processing device connected from the modular plug 10 via the signal cable 30 is connected to the surge voltage Vsu.
Effective protection from rge is possible.

In particular, according to the configuration described above, the modular plug 10 that can be freely handled on the user side can prevent the propagation of the surge voltage Vsurge applied through the communication line, so that the gas can be temporarily stored in the protector. Even if the overvoltage protection circuit consisting of a tube arrester, zinc oxide varistor, etc. is not built in, or if its characteristics are degraded, the user can easily and effectively use the surge voltage It is possible to take protective measures against Vsurge. That is, even a user who does not have a special qualification such as a construction engineer can effectively protect the data processing device from the surge voltage Vsurge caused by the induced lightning, and can effectively function as a self-defense means. .

The surge voltage V applied between specific signal lines
In order to protect the device to be protected from surge, the thyristor 20 may be interposed between the lines as shown in FIG. 8 (a), and between each of the signal lines and the ground line. To protect the device to be protected from an applied surge voltage Vsurge, two silicon two-way two-terminal thyristors 20 are interposed between the lines in a cascade as shown in FIG. What is necessary is just to make it ground.

In the above-described embodiment, the modular plug 10 mounted on the signal cable 30 has a structure in which the silicon two-way two-terminal thyristor 20 is directly incorporated. It can also be realized as a relay adapter structure interposed between the modular outlet. FIG. 9 and FIG. 10 are schematic configuration diagrams showing structural examples of the overvoltage protection device realized as the modular type relay adapters 40 and 50. FIG.

The feature of the relay adapters 40 and 50 is that the modular adapter shown in FIG.
Compared to the plug 10, the holding portion 11 of the signal cable 30
In place of c, modular outlet portions 41 and 51 to which other modular plugs are detachably attached are provided, and one end of the electrode wiring body 12 is directly extended to the modular outlet portions 41 and 51. In that the outlets 41, 51 are formed as electrodes 42, 52. The recess 11d and the lid 13 are basically configured in the same manner as the above-described structure.

That is, the relay adapter 4 having the structure shown in FIG.
Numeral 0 indicates that the modular outlet 41 is formed in the same direction as the plug 11a. One end of the electrode wiring body 12 extending to the outlet 41 is largely bent downward, and is extended along the bottom surface of the outlet 41 toward the opening, and then the tip is bent upward in a F-shape. The electrode 42 has a spring property.

On the other hand, the relay adapter 50 having the structure shown in FIG. 10 is formed by turning the modular outlet portion 51 in the opposite direction to the plug portion 11a, that is, by turning it upside down. One end of the electrode wiring body 12 extending to the outlet 41 is provided with the recess 11.
After extending straightly to the opening side along the bottom surface of the outlet portion 41 formed as the same surface as the bottom surface of d, the tip portion is bent downward in a F-shape to form the electrode 5 having a spring property.
It is set to 2.

In addition, the electrode wiring body 12 having the above-mentioned shape with one end having the electrodes 42, 52 of the outlets 41, 51 is incorporated into the recess 11d from the opening side of the outlets 41, 51 toward the recess 11d. This is performed by inserting the electrode wiring body 12. Then, after the electrode wiring body 12 is incorporated in the concave portion 11d, the silicon two-way two-terminal thyristor 20 is housed in the concave portion 11d, and the lid 13 is put on the thyristor 20 for bonding and integration. By doing so, the assembly is performed.

Thus, according to the relay adapters 40 and 50 having such a structure, the thyristor 20 built in the relay adapters 40 and 50 can be simply mounted between the modular plug and the modular outlet. The surge voltage V due to the induced lightning applied from the communication line
The surge can be effectively absorbed. In other words, by simply interposing the relay adapters 40 and 50 at the communication signal line of the data processing device, particularly at the connection between the modular outlet and the modular plug, the data processing device can be easily and effectively removed from the surge voltage Vsurge. Effective protection can be achieved.

Moreover, the relay adapter 4 having the above-described structure.
According to O.50, one end of the electrode wiring board 12 is directly used as the electrodes 42,52 of the outlets 41,51, so that the overall structure can be simplified and the number of components can be reduced. An effect can also be achieved. Note that the present invention is not limited to the above-described embodiments. For example, the present invention is applicable not only to a modular connector but also to other connector structures. Furthermore, the number of connection terminals in the connector is not particularly limited, and when there are three or more connection terminals (signal lines), the thyristor 20 described above is interposed between the connection terminals to which the surge voltage Vsurge may be applied. What should I do? In this case, for an electrode wiring body that does not need to be connected to the thyristor 20, the intermediate portion may not be formed so as to be wide and may not be in contact with the terminal 21 of the thyristor 20. Also, the relay adapter 40,
When this device is realized as 50, its external shape and the like are F
What is necessary is just to determine according to the specification while complying with the CC standard. In short, the present invention can be variously modified and implemented without departing from the gist thereof.

[0035]

As described above, the overvoltage protection device according to the present invention absorbs an overvoltage applied from the outside via the outlet to a plug which is detachably attached to the outlet and electrically connected to the outlet. In particular, a plug body which forms a main part of the plug is provided with a plug body at one end and a lead wire holding part or another plug at the other end. Outlet, and the silicon 2 in the middle
It has a structure in which a recess for accommodating a directional two-terminal thyristor is formed. A pair of electrode wiring bodies each having a contact portion with the terminal portion of the thyristor is provided in the recess, and one end of the electrode wiring body is electrically connected to a lead wire held by the holding section. The other end of the electrode portion or the outlet portion is a contact connecting portion extending to the plug portion.

Then, the silicon two-way two-terminal thyristor housed in the recess is fixedly held by a lid closing the recess, and the terminal portions of the thyristor are brought into contact with the contact portions of the respective electrode wiring bodies. After that, the electrode chips are respectively fitted to the contact connection portions of the electrode wiring bodies, and are fixedly held to the plug body. Therefore, according to the present invention, even when a plug body to be attached to the end of the lead wire is configured as described in claim 1, or a relay adapter structure is configured as described in claim 2. Even in this case, the assembly structure can be simplified, and the assembly and electrical connection can be completed easily. Moreover, the electrical connection of each part can be ensured by the mechanical and structural contact / engagement structure without performing processing such as soldering, and the structure can be made very strong. And the like, a great effect is obtained in practical use.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram showing an application example to a modular plug which is an embodiment of an overvoltage protection device according to the present invention.

FIG. 2 is an exploded perspective view showing an assembly structure of the modular plug shown in FIG. 1;

FIG. 3 is a diagram schematically showing an external shape of a silicon two-way two-terminal thyristor incorporated in the overvoltage protection device according to the present invention.

FIG. 4 is a diagram showing an element structure of a silicon two-way two-terminal thyristor and a configuration of an electrical equivalent circuit thereof.

FIG. 5 is a diagram showing VI characteristics of a silicon two-way two-terminal thyristor.

FIG. 6 is a diagram showing an example of an overvoltage protection circuit using a silicon two-way two-terminal thyristor.

7 is an operation characteristic diagram showing an overvoltage protection action by a silicon two-way two-terminal thyristor in the circuit shown in FIG. 6;

FIG. 8 is a diagram showing a basic usage example of a silicon two-way two-terminal thyristor.

FIG. 9 is a cross-sectional configuration diagram showing an application example to a modular relay adapter which is another embodiment of the overvoltage protection device according to the present invention.

FIG. 10 is a cross-sectional configuration diagram showing an application example to a modular relay adapter which is still another embodiment of the overvoltage protection device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plug 11 Plug main body 11a Plug part 11c Holding part 11d Depression 12 Electrode wiring body 13 Lid 14 Electrode chip 20 Silicon two-way two-terminal thyristor 30 Signal cable 40 Modular type relay adapter 50 Modular type relay adapter

Claims (2)

[Claims] 1. A plug which is detachably attached to an outlet and is electrically connected to the outlet, and a silicon two-way two-terminal thyristor which is built in the plug and absorbs an overvoltage applied from the outside via the outlet. The plug has a plug portion that can be attached to the outlet at one end, a lead wire holding portion at the other end, and a recess for accommodating the silicon two-way two-terminal thyristor at an intermediate portion. A plug body, one end of which is an electrical connection portion with a lead wire held by the holding portion, and the other end of which is a contact connection portion extended to the plug portion,
A pair of electrode wiring bodies disposed along the bottom of the concave portion and having an intermediate portion as a contact portion with a terminal portion of the silicon two-way two-terminal thyristor; A cover for closing and holding the recess by fixing and holding the silicon two-way two-terminal thyristor that is in contact with the contact portion of each electrode wiring body; An electrode tip fixedly held by the plug body and forming a connection contact with an electrode of the outlet. 2. A plug which is detachably attached to an outlet and is electrically connected to the outlet, and a silicon two-way two-terminal thyristor which is built in the plug and absorbs an overvoltage applied from the outside via the outlet. The plug has a relay adapter structure in which one end side has a plug portion that can be attached to the outlet, and the other end side has an outlet portion to which another plug is attached. A plug body formed with a recess for accommodating a directional two-terminal thyristor; one end serving as an electrode in the outlet portion; and the other end serving as a contact connection portion extending to the plug portion, and disposed along the bottom of the recess. A pair of electrode wiring bodies each having a middle part thereof in contact with a terminal part of the silicon two-way two-terminal thyristor; A lid for fixing and holding the silicon two-way two-terminal thyristor in contact with the contact portion of each of the electrode wiring bodies and closing the recess, and provided so as to be fitted to the contact connection portions of the electrode wiring bodies, respectively; An electrode tip fixedly held by the plug body and forming a connection contact with an electrode of the outlet.