JPH01128387A - Gap switch - Google Patents

Abstract

PURPOSE:To obtain a gap switch with little unevenness of trigger discharge formation and a secure discharge ignition between an anode and a cathode by furnishing a dielectric which can form a surface discharge between a trigger electrode and the edge of a discharge electrode. CONSTITUTION:In a hole 5 of a hollow formed in an anode 4, a cylindrical dielectric 11 with bottom is inserted contacting closely. The dielectric 11 is formed to have its outer surface 12 between a trigger electrode 6 and the edge 8 of the anode 4 formed at the open periphery of the hole 5. And it is formed to generate a surface discharge along the outer surface 12 between the electrode 6 and the edge 8. A high voltage trigger pulse is applied between the anode 4 and the electrode 6 in such a composition. As a result, a surface discharge (b) is generated along the outer surface 12, which acts as a trigger to generate a discharge between a cathode 3 and the anode 4. In such a composition, a gap switch to generate little uneven formation of the surface discharge (b) and to secure a discharge between the cathode 3 and the anode 4 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a gap switch that is often used in large current switches such as pulsed lasers and Marx banks.

(Prior Art) Gap switches are often used in large current switches such as pulse lasers and Marx banks. The structure of this kind of conventional gap switch is as shown in FIG. That is, the switch body 1 is made of an electrically insulating material such as acrylic or polyethylene and is formed into a (cylindrical) shape, and a pleat 2 for preventing creeping discharge is formed on the outer peripheral surface of the switch body 1. An anode 3 is attached to one open end of the switch body 1 so as to close the opening. In addition, at the other front end of the switch body 1, there is a gruesome 4
is arranged 81 to close the opening. In other words,
The interior of the switch body 1 is hermetically sealed by an anode 3 and a cathode 4, which form a hollow portion 1a inside. Air at a predetermined pressure is sealed within this hollow portion 1a.

Further, a circular hole 5 is provided through the cathode 4 approximately in the center thereof, and an electrical insulator 7 holding a trigger electrode 6 is screwed into the hole 5 in an airtight manner. This trigger electrode 6 is electrically insulated from the cathode 4 by an electrical insulator 7 that holds it.

This gap switch is not shown in either the anode 3 or the cathode 4! ! A source is connected to the other end, a load (not shown) is connected to the other end, and a high voltage is applied between the anode 3 and the cathode 4. Therefore, when a high voltage trigger pulse is input between the cathode 4 and the trigger electrode 6, an ignition a is generated between the trigger electrode 6 and the edge portion 8 of the cathode 4 as shown in FIG. A discharge occurs, which becomes a spark, causing a discharge to occur between the anode 3 and the cathode 4, thereby causing a current to flow between the power source and the load.

(Problem to be Solved by the Invention) However, with the above configuration, there is a large variation in the delay in discharge formation between the trigger electrode 6 and the edge portion 8 of the cathode 4, so this kind of gap When two switches are fired at the same time or when two gap switches are switched at a certain timing, the jitter of the gap switches becomes a big problem. This jitter is largely influenced by variations in the delay in discharge formation between the trigger electrode 6 and the edge portion 8 of the cathode 4.
This needs to be made smaller.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a gap switch which can reduce switching time jitter as much as possible and which can be triggered reliably.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides an electrically insulating cylindrical body and a cylindrical body that seals both openings of the cylindrical body and An electrode consisting of an anode and a cathode for switch discharge, which together with the cylindrical body form a hollow part for enclosing gas, and a cavity formed in at least one of these electrodes and opening facing the other electrode. a trigger electrode that passes through the cavity and is provided at a position where its tip end discharges with the edge of the cavity, and an electrical insulator that inserts and supports the trigger electrode and closes the cavity. In the switch, a dielectric part that forms a creeping discharge between the one electrode and the edge part is provided on the other electrode side of the electrical insulator at a position where the edge part is exposed, and the trigger The electrode is provided with its tip portion protruding from the dielectric material into the hollow portion.

(Function) Therefore, a dielectric portion that forms a creeping discharge between the one electrode and the edge portion is provided on the other electrode side of the electrical insulator at a position where the edge portion is exposed. At the same time, since the trigger N pole is provided with its tip protruding from the dielectric body into the hollow part, a trigger occurs between the trigger electrode and the edge part of the discharge electrode due to the creeping discharge action of the dielectric body. Discharge occurs reliably. Therefore, jitter during switching can be significantly reduced. Furthermore, the voltage required for creeping discharge can also be reduced.

Furthermore, when creeping discharge occurs on the surface of the dielectric, the discharge generates strong ultraviolet rays, which photoionizes the gas between the anode and cathode. This makes discharge ignition more reliable and greatly reduces so-called mis-triggering.

(Embodiment) FIGS. 1 and 2 show a first embodiment of the present invention. Among the configurations of the gap switch of this embodiment, the same components as those explained based on FIG.

A feature of this embodiment is that a bottomed cylindrical dielectric portion 11 is inserted into a hole 5 formed in the cathode 4 as a hollow portion. Furthermore, this dielectric part 11 is formed to have an outer surface 12 that runs along between the trigger electrode 6 and an edge part 8 formed on the opening periphery of the hole 5 in the cathode 4. A creeping discharge is caused to occur on the outer surface 12 of the dielectric portion 11 between the dielectric portion 8 and the dielectric portion 8 .

The material of the dielectric portion 11 is, for example, titanium oxide (
TiOx), alumina ceramic (AJ220!)
, epoxy glass, etc. are suitable.

In the case of this gap switch, a power source (not shown) is connected to either one of the anode 3 or cathode 4, and a load (not shown) is connected to the other, as described above.
In order to apply a high voltage between the anode 3 and the cathode 4, a high voltage trigger pulse is applied between the cathode 4 and the trigger electrode 6. Then, the outer surface 1 of the dielectric portion 11 between the trigger electrode 6 and the edge portion 8 of the cathode 4
2, a creeping discharge as shown in FIG. 2 occurs.

Then, this becomes a spark and discharge occurs between the anode 3 and the cathode 4, so that a current flows between the power source and the load.

In this way, the discharge between the trigger electrode 6 and the edge portion 8 of the cathode 4 is generated by the creeping radiation ib on the outer surface 12 of the dielectric portion 11, so that the discharge occurs reliably and the creeping discharge is formed. The variation in lag is very small. therefore,
Even when two gap switches are fired at the same time or when two gap switches are switched at a fixed timing, the jitter that occurs during operation can be significantly reduced. Therefore, the switching time delay is usually reduced to less than 1/10. In addition, the voltage required for creeping discharge is 5 KV/cm, which is 1/4 of the 20 KVloll of the conventional structure.
becomes. In other words, the trigger voltage input between the anode 3 and the cathode 4 can be made extremely small.

Further, when a creeping discharge occurs on the outer surface 12 of the dielectric portion 11, strong ultraviolet rays are generated by the discharge, and this ultraviolet rays photoionize the gas between the anode 3 and the cathode 4, so that the anode To ensure more reliable discharge ignition between 3 and cathode 4.

Therefore, mistriggering, a phenomenon in which the discharge between the anode 3 and the cathode 4 does not ignite even when a trigger pulse is input, is significantly reduced.

Note that the present invention is not limited to the above embodiments. For example, the trigger electrode 6 may be provided on the anode side instead of the cathode. Further, the dielectric portion may be molded and attached so as to fill the cavity. Roughly,
In the above embodiment, the electrical insulator and the dielectric portion are separate, but the tip of the electrical insulator may be extended and this extended portion may be used as the dielectric portion.

[Effects of the Invention] As explained above, according to the present invention, the trigger discharge between the trigger electrode and the edge part of the discharge electrode is performed by creeping discharge on the surface of the dielectric part, so the discharge is ensured. The variation in the formation delay of creeping discharge is very small. Therefore, for example, even when two gap switches are turned on at the same time or when two gap switches are switched at a constant timing, the jitter that occurs during operation can be significantly reduced. Furthermore, the voltage required for creeping discharge can be much smaller than that of conventional discharge types.

Furthermore, when a creeping discharge occurs on the surface of the dielectric part, the discharge generates strong ultraviolet rays, and this ultraviolet rays photoionize the gas between the anode and cathode. This makes the discharge ignition more reliable and greatly reduces so-called mis-triggering.

[Brief explanation of the drawing]

1 and 2 show embodiments of the present invention;
The figure is a side sectional view of the gap switch, FIG. 2 is a bottom view of the vicinity of the trigger electrode, and FIG. 3 is a side sectional view of a conventional gap switch. 1...Switch body, 3...Anode, 4...Cathode,
5... Hole, trigger electrode, 7... Electrical insulator, 8
. . . Edge portion, 11 . . . Dielectric portion, 12 . . . Outer surface. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] It consists of a cylindrical body having electrical insulation properties, and an anode and a cathode for switch discharge, which seal both openings of this cylindrical body and face each other to form a hollow part that encloses gas together with the cylindrical body. An electrode, a cavity formed in at least one of these electrodes and opening opposite to the other electrode, a trigger electrode passing through this cavity and provided at a position where a tip thereof discharges with an edge of the cavity; In a gap switch comprising an electrical insulator through which a trigger electrode is inserted and supported and which closes the cavity, creeping discharge occurs between the one electrode and the edge portion on the other electrode side of the electrical insulator. A gap switch characterized in that a dielectric portion forming the trigger electrode is provided at a position where the edge portion is exposed, and the trigger electrode is provided with a tip thereof protruding from the dielectric into the hollow portion.