Abstract: The 3-electrode surge protective device includes: a surge protective device body including: an earth electrode; a ceramic cylinder; and a pair of line electrodes; and a fail-safe spring including: an elastic mount portion; and a short-circuit portion, a conductive material that is sandwiched between the fail-safe spring and the body; and a pair of first lead pins provided on the pair of line electrodes; a second lead pin provided on the earth electrode. In a normal state, the conductive material support the short-circuit portion at a separation position where the short-circuit portion is separated from the outer peripheral face of the body and the first lead pins. In case where the body is overheated and the conductive material is melted, the short-circuit portion is moved to a contact position where the short-circuit portion comes into contact with the second lead pin and the first lead pins.

Abstract: The 3-electrode surge protective device includes: a surge protective device body including: an earth electrode; a ceramic cylinder; and a pair of line electrodes; and a fail-safe spring including: an elastic mount portion; and a short-circuit portion, a conductive material that is sandwiched between the fail-safe spring and the body; and a pair of first lead pins provided on the pair of line electrodes; a second lead pin provided on the earth electrode. In a normal state, the conductive material support the short-circuit portion at a separation position where the short-circuit portion is separated from the outer peripheral face of the body and the first lead pins. In case where the body is overheated and the conductive material is melted, the short-circuit portion is moved to a contact position where the short-circuit portion comes into contact with the second lead pin and the first lead pins.

Abstract: A surface mounting discharge tube, comprise of a cylindrical ceramic envelope sealed at its two ends by side surfaces of electrodes, designed to be directly soldered on to a mounting board, where the electrodes at the two ends are rectangular, project outward radially at the ends of the ceramic envelope and are provided at peripheral edges at the side surfaces of the electrodes with soldering use tapers or step differences, whereby positional deviation at the time of soldering is suppressed and sufficient PCT properties are secured.

Abstract: A discharge tube comprises a pair of discharge electrodes opposed to each other with a discharge space in-between, an airtight cylinder in which the discharge space is formed, the pair of the electrodes respectively being mounted on both ends of the airtight cylinder, and a coating film which is resistant to water permeation, and formed on a surface of the airtight cylinder. With the discharge tube, it is possible to perform a stable discharge having a good insulating property between the discharge electrodes even when the external environment changes.

Abstract: A discharge tube includes a cylinder having first and second end planes, first and second discharge electrodes coupled to the respective first and second end planes, the first and second discharge electrodes having respective upper and lower discharge planes forming therebetween a discharge gap, and one or more discharge trigger wires disposed in a portion of the cylinder that encompasses the discharge gap.

Abstract: In a discharge tube of the present invention, a filler gas is composed of a mixture of inert gas and hydrogen gas and an airtight cylinder 10 in which the filler gas is enclosed in an airtight manner is provided. A pair of first and second discharge electrodes 22 and 24 are opposed to each other within an internal space of the airtight cylinder, so that an electric discharge is generated between discharging surfaces of the first and second discharge electrodes. In the discharge tube, a concentration of the hydrogen gas in the filler gas is set in a range from 20 percent by volume to 80 percent by volume.

Abstract: A discharge tube is disclosed that includes: an airtight tube having first and second end surfaces each including a metallized surface; first and second discharge electrodes joined to the respective metallized surfaces; and multiple trigger lines formed on the inner wall surface of the airtight tube to extend along the axial directions of the airtight tube. The first and second discharge electrodes are joined to the metallized surfaces so that a discharge gap is formed between the first and second discharge electrodes and the airtight tube is hermetically sealed. The trigger lines include one or more first trigger lines connected to the metallized surfaces and multiple second trigger lines isolated from the metallized surfaces. The second trigger lines are formed at equal intervals on the inner wall surface of the airtight tube and each first trigger line is formed between a corresponding pair of the second trigger lines.

Abstract: A discharge tube comprises a pair of discharge electrodes opposed to each other with a discharge space in-between, an airtight cylinder in which the discharge space is formed, the pair of the electrodes respectively being mounted on both ends of the airtight cylinder, and a coating film which is resistant to water permeation, and formed on a surface of the airtight cylinder. With the discharge tube, it is possible to perform a stable discharge having a good insulating property between the discharge electrodes even when the external environment changes.

Abstract: A surface mounting discharge tube, comprise of a cylindrical ceramic envelope sealed at its two ends by side surfaces of electrodes, designed to be directly soldered on to a mounting board, where the electrodes at the two ends are rectangular, project outward radially at the ends of the ceramic envelope and are provided at peripheral edges at the side surfaces of the electrodes with soldering use tapers or step differences, whereby positional deviation at the time of soldering is suppressed and sufficient PCT properties are secured.

Abstract: A discharge tube comprised of a cylinder ceramic envelope sealed at its two ends by plate-shaped positive electrode and negative electrode, wherein the entire outside circumference of at least the negative electrode end of the ceramic envelope is printed with insulating ink, whereby it is possible to prevent insulation degradation due to deposition or dirt or moisture on the surface of the envelope and greatly lighten the burden of handling and maintenance and management.

Abstract: A discharge tube is disclosed that includes: an airtight tube having first and second end surfaces each including a metallized surface; first and second discharge electrodes joined to the respective metallized surfaces; and multiple trigger lines formed on the inner wall surface of the airtight tube to extend along the axial directions of the airtight tube. The first and second discharge electrodes are joined to the metallized surfaces so that a discharge gap is formed between the first and second discharge electrodes and the airtight tube is hermetically sealed. The trigger lines include one or more first trigger lines connected to the metallized surfaces and multiple second trigger lines isolated from the metallized surfaces. The second trigger lines are formed at equal intervals on the inner wall surface of the airtight tube and each first trigger line is formed between a corresponding pair of the second trigger lines.

Abstract: A discharge tube includes a cylinder having first and second end planes, first and second discharge electrodes coupled to the respective first and second end planes, the first and second discharge electrodes having respective upper and lower discharge planes forming therebetween a discharge gap, and one or more discharge trigger wires disposed in a portion of the cylinder that encompasses the discharge gap.

Abstract: In a discharge tube of the present invention, a filler gas is composed of a mixture of inert gas and hydrogen gas and an airtight cylinder 10 in which the filler gas is enclosed in an airtight manner is provided. A pair of first and second discharge electrodes 22 and 24 are opposed to each other within an internal space of the airtight cylinder, so that an electric discharge is generated between discharging surfaces of the first and second discharge electrodes. In the discharge tube, a concentration of the hydrogen gas in the filler gas is set in a range from 20 percent by volume to 80 percent by volume.

Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube.

Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube. A gas filled switching electric discharge tube comprises: a cylindrical body (1) made of insulating material; two electrodes (2, 3) for airtightly closing both ends of the cylindrical body; an electric discharge gap, an airtightly closed space formed in the cylindrical body including the electric discharge gap being filled with gas; metallized faces formed on both end faces of the electrodes of the cylindrical body; first trigger wires (10a, 10b) formed on an inner wall face of the cylindrical body, connected with the metallized faces; and second trigger wires (10c) formed on the inner wall face of the cylindrical body, not connected with the metallized faces, wherein the first electrode face and second electrode face are plated with copper or silver.

Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube. A gas filled switching electric discharge tube comprises: a cylindrical body (1) made of insulating material; two electrodes (2, 3) for airtightly closing both ends of the cylindrical body; an electric discharge gap, an airtightly closed space formed in the cylindrical body including the electric discharge gap being filled with gas; metallized faces formed on both end faces of the electrodes of the cylindrical body; first trigger wires (10a, 10b) formed on an inner wall face of the cylindrical body, connected with the metallized faces; and second trigger wires (10c) formed on the inner wall face of the cylindrical body, not connected with the metallized faces, wherein the first electrode face and second electrode face are plated with copper or silver.

Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube.

Abstract: A three-electrode-discharge surge arrester has two opposing discharging parts of a pair of line electrodes, defining a gap therebetween, and a ground electrode disposed between the two discharging parts and provided with a penetration hole in the center. Each of the two discharging parts has a substantially conical shape. In accordance with this substantially conical shape, each of inner surfaces of upper and lower parts of the penetration hole of the ground electrode is substantially funnel-shaped. Hence, oblique parallel gaps for a primary discharge are formed between the substantially funnel-shaped inner surfaces of the upper and lower parts of the penetration hole and the two substantially conical discharging parts. Also, parallel gaps for a secondary discharge are formed between peripheral parts of the ground electrode around the penetration hole and peripheral parts of the line electrodes. Each of the oblique parallel gaps is formed narrower than each of the parallel gaps.

Abstract: An electrical discharge tube comprises a cylindrical body, made of insulating material, having an inner surface, and having end faces defining respective openings. Metallized layers are formed on the respective end faces of the cylindrical body and are substantially parallel to each other. Electrodes airtightly close the respective openings by means of the metallized layers and have respective electrical discharge faces, between which an electrical discharge gap is defined. At least one first electrical discharge trigger wire is formed as a loop on the inner surface of the cylindrical body and extends substantially in parallel to the metallized layers along a first surface located within a range of the electrical discharge gap.

Abstract: A three-electrode-discharge surge arrester has two opposing discharging parts of a pair of line electrodes, defining a gap therebetween, and a ground electrode disposed between the two discharging parts and provided with a penetration hole in the center. Each of the two discharging parts has a substantially conical shape. In accordance with this substantially conical shape, each of inner surfaces of upper and lower parts of the penetration hole of the ground electrode is substantially funnel-shaped. Hence, oblique parallel gaps for a primary discharge are formed between the substantially funnel-shaped inner surfaces of the upper and lower parts of the penetration hole and the two substantially conical discharging parts. Also, parallel gaps for a secondary discharge are formed between peripheral parts of the ground electrode around the penetration hole and peripheral parts of the line electrodes. Each of the oblique parallel gaps is formed narrower than each of the parallel gaps.