JP2002289317A - Lighting arrester for communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand an applicable range to a high frequency band range and increase the tolerable current amount several times and suppress generation of follow currents. SOLUTION: In a lightning arrester 1 for communication comprised of a cylindrical insulating tube 2 having openings on both ends, a carbon wire 3 mounted on the inner peripheral wall 2a of the insulating tube, an electrode 4 consisting of copper materials wherein discharging faces 4c1 are fitted opposing to the openings of the both ends of the insulating tube and a gas filled in the inside of the insulating tube, the carbon wire mounted on the inner peripheral wall is constituted in such a way that it will not contact with the electrode, and the discharging gap width 6 formed by discharging faces of the electrode is made to be 0.4 to 0.7 mm and further the main component of the gas filled into the insulating tube is made to be argon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a communication line, which absorbs an excessive surge such as lightning invading the communication line,
TECHNICAL FIELD The present invention relates to a communication lightning arrester (gas arrester) for protecting devices connected to a communication line, and more particularly to a communication lightning arrester suitable for a communication line on which a DC power supply is superimposed.

[0002]

2. Description of the Related Art It is known to use a gap-type lightning arrester to protect equipment connected to a communication line from an excessive surge such as lightning that has entered a communication line. In addition, when DC power is superimposed on the communication line, in order to prevent follow-up current, devices such as varistors are used in combination with varistors to prevent equipment connected to the communication line from surges, etc. It is also known to protect and block the downstream flow. Further, since a gap type lightning arrester has a time delay at the start of discharge, there is also known a lightning arrester configured to improve the delay of the discharge start time by attaching a carbon wire in parallel with the discharge gap. Furthermore, it is also known that a gap type lightning arrester has a low glow voltage (a voltage between terminals during a discharging operation) and is likely to cause a follow current. Still further, it is also known to use iron, nickel, Kovar, copper or the like as an electrode material.

[0003]

Today, communication technologies such as mobile phones and the Internet are making remarkable progress, and communication circuits are shifting from analog to digital. Accordingly, the frequency used has been shifted to a higher frequency band, but the required frequency band of the conventional frequency band is at most about MHz, and at most is less than 1 GHz. However, at present, the frequency band is as high as 1 to 3 GHz. However, at higher frequencies,
It is necessary to improve the transmission loss and the reflection characteristics (VSWR), the delay of the discharge start time at a high frequency, the countermeasures against the continuation of the power supply voltage superimposed on the communication line, and the current withstand capability.

In order to improve the delay of the discharge start time, a carbon wire or the like attached to the inner peripheral wall of the insulating tube has an influence, so that a transmission loss and a loss of a reflection characteristic (VSWR) are increased. When the frequency band is increased and the current withstand capability is increased, there is a problem that one improvement leads to the occurrence of other plural problems, such as lowering the glow voltage and easily generating a subsequent current.

An object of the present invention is to solve the problems of the above-mentioned conventional communication lightning arrester.

[0006]

In order to achieve the above-mentioned object, the present invention provides a cylindrical insulating tube having openings at both ends, a carbon wire attached to an inner peripheral wall of the insulating tube, In a communication lightning arrester comprising an electrode made of a copper material fitted to openings at both ends of the insulating tube so that a discharge surface faces each other, and a gas filled in the insulating tube, an inner peripheral wall in the insulating tube is provided. The carbon wire attached to the electrode is configured not to contact the electrode, and the discharge gap formed by the discharge surface of the electrode is 0.4 to 0.7 mm,
Further, the main component of the gas filled in the insulating tube is argon.

[0007]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited to the embodiment unless it exceeds the gist of the present invention.

Reference numeral 1 denotes a communication lightning arrester. The communication lightning arrester 1 mainly includes a cylindrical insulating tube 2 and a carbon wire 3 attached to an inner peripheral wall 2a of the insulating tube 2 at a predetermined interval. A substantially disk-shaped electrode 4 fitted into the opening at both ends of the cylindrical insulating tube 2, and a space 5 closed by the pair of electrodes 4 facing the insulating tube 2 includes: Gas filled. The carbon wire 3 is attached so as not to come into contact with the electrode 4.
Along the axial direction of the insulating tube 2 at an angle 9
It is attached at intervals of 0 degrees. The insulating tube 2 has alumina as a main component, and the carbon wire 3 has a line width of 1 mm or less, and in many cases, a line width of about 0.5 mm, and is attached in a straight line. The interval between the carbon wires 3 is
The angle is not limited to 90 degrees.

The electrode 4 covers the annular horizontal portion 4a, the cylindrical portion 4b extending downward from the inner peripheral edge of the annular horizontal portion 4a, and covers the lower end of the cylindrical portion 4b, and forms a flat discharge surface 4c1. It is formed from a disc-shaped discharge portion 4c and is formed of a copper material.

[0010] A discharge gap 6 is formed between the discharge surfaces 4c1 of the pair of opposing electrodes 4 fitted into the openings at both ends of the insulating tube 2. The distance between the opposing discharge gaps 6 is 0.4 to 0.7 mm, and the gas sealed in the space 5 closed by the insulating tube 2 and the electrode 4 is mainly composed of argon, and has a capacity of 40 vol. % Or less,
Preferably, 3 to 40% by volume of hydrogen is charged.

The discharge surface 4c1 of the electrode 4 has a large number of recesses 4
d is formed, and the discharge activating material 7 is filled in the concave portion 4d. In this embodiment, the discharge activating material made of molybdenum alone is made into a powder form and press-filled into the recess 4 d formed on the discharge surface 4 c 1 of the electrode 4. As the discharge activating material 7, in addition to molybdenum, manganese,
A simple substance such as niobium, tantalum, tungsten, or aluminum or a compound thereof can also be used. In addition, cellulose acetate, polyvinyl alcohol, polyvinyl butyrol, or the like can be mixed with the discharge activating material 7 as an auxiliary material. In this embodiment, a mixture of 5 to 10% by volume of a mixture of cellulose acetate, polyvinyl alcohol and polyvinyl butyrol as auxiliary materials is used in 90 to 95% by volume of molybdenum simple substance as the discharge activating material 7. ing.

In the communication lightning arrester 1 having the above-described configuration, in a frequency band of 300 KHz to 3 GHz, the reflection characteristic (VSWR) is 1.2 or less, the insertion loss is suppressed to -0.2 dB or less, and the current withstand capability is reduced. 50 KA was achieved with an impulse current waveform of 8 × 20 μs. Further, as a follow-on current test, under the condition that a DC voltage of 52 V and a current of 5 A were supplied, the power supply circuit was supplied with a current of 10/1000 μs for 10/1000 μs.
Even when an impulse of 0 A was applied, the subsequent flow was interrupted in a time of 7.6 ms or less.

As described above, the carbon wire 3 is connected to the electrode 4
As described above, the carbon wire 3 is attached to the inner peripheral wall 2a of the insulating tube 2 so as not to contact with it, and it is formed to be narrow and narrow in width as described above.
The gas sealed in the space 5 closed by the insulating tube 2 and the electrode 4 is about 4 to 0.7 mm, and hydrogen gas is mixed with argon as a main component.
Conventionally, due to the synergy of the use of the copper material and the synergy of disposing the discharge activating material 7 mixed with an auxiliary material on the discharge surface 4c1 of the electrode 4, if necessary, the frequency band is conventionally increased. , Up to about MHz, can be expanded to 3 GHz band, and the glow discharge voltage
What was conventionally 50 V or less can be increased to about 180 to 200 V, and the impulse current withstand capability can be increased to 20 to 50 KV instead of the conventional 5 to 10 KV.
KV, and the occurrence of the conventional follow-up flow could be avoided.

[0014]

According to the present invention, the following effects can be obtained by the configuration described above.

[0015] The range of use can be extended to a high frequency band, the current withstand capability can be made several times as large as that of the conventional one, and the generation of a follow-up current can be suppressed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a communication lightning arrester according to an embodiment of the present invention.

[Explanation of symbols]

 1 Lightning arrester for communication 2 Insulating tube 3 Carbon wire 4 Electrode 6 ... Discharge gap

Claims (1)

[Claims] A cylindrical insulating tube having openings at both ends;
A carbon wire attached to an inner peripheral wall of the insulating tube, an electrode made of a copper material fitted to openings at both ends of the insulating tube so that discharge surfaces face each other, and filled in the insulating tube. In a communication lightning arrester made of gas, a carbon wire attached to an inner peripheral wall in the insulating tube is configured not to contact the electrode, and a discharge gap formed by a discharge surface of the electrode is set to 0. A communication lightning arrester having a diameter of 4 to 0.7 mm, and further comprising argon as a main component of a gas filled in the insulating tube.