Multi-clearance ceramet gas discharge tube with circumscribing triggering terminal

Abstract

The invention relates to the technical field of discharge tubes, in particular to a multi-gap metal ceramic gas discharge tube with external contact terminals, which comprises a ceramic locating nail, a metalized ceramic insulator, a discharge gap electrode separator, a discharge gap transitional connection separator, a screw electrode and terminals; the two ends of at least two layers of ring metalized ceramic insulators are connected with the screw electrode so as to form multi-gap space sealed with inert gas; the ring metalized ceramic insulators are integrally formed with a ring flange; the upper end surface and the lower end surface of the ring flange support two electrode separators with the discharge gap; the electrode separators with the discharge gap are provided with ceramic locating nail holes and discharge extending holes; the discharge gap transitional connection separator is arranged between the two metalized ceramic insulators and opened with the discharge extending holes; and after terminal overvoltage is integrally formed on the discharge gap transitional connection separator, the discharge tube is extinguished automatically, thus achieving the result of no after-flow.

Description

Technical field: [0001] The invention relates to the technical field of discharge tubes, in particular to a multi-gap metal-ceramic gas discharge tube which can self-extinguish after a lightning overvoltage in a high-voltage power supply system. Background technique: [0002] As a switching element that only depends on voltage, the metal-ceramic discharge tube is widely used in the signal system of electronic equipment to protect against lightning and electromagnetic pulse band The damage caused by the overvoltage to the electronic equipment; the application in the current electronic equipment power supply system is limited to the equipotential isolation grounding, which is used to solve the crosstalk caused by the common ground in the electronic equipment power supply and signal lightning strike overvoltage protection scheme interference problem. [0003] At present, the single-gap metal-ceramic gas discharge tubes used in the world have a common defect: in the lightning p...

AI Technical Summary

Problems solved by technology

[0003] At present, the single-gap cermet gas discharge tubes used in the world all have a common defect: in the lightning protection of the strong power supply system, the single-gap cermet gas discharge tube After the lightning overvoltage of the tube, because the power supply system can provide the voltage and current to maintain the discharge, the overvoltage cannot be shut down automatically after the overvoltage

[0006] First, due to the existence of the leakage current of the inherent characteristics of MOV, the leakage current of MOV in the long-term leakage current environment in the power system will become larger and larger, which is the so-called aging, which will cause the MOV to short-circuit due to thermal breakdown, and thus cause The hidden danger of fire is also the fundamental reason why the power supply lightning protection box often catches fire

The vast number of lightning protection engineering and technical personnel have made various efforts, although they have greatly improved, but they cannot fundamentally solve this problem

[0007]Second, as a non-linear resistor, the MOV has a high voltage drop during lightning strike overcurrent, and there is no freewheeling problem in the lightning strike protection of the power system. This is its advantage, but it is also It brings high power consumption. When an unbearable overcurrent passes through, the MOV will explode and open the circuit

[0008]Third, from the above situation, the failure mode of MOV is uncertain, which brings unpredictable results to the application

[0009] Fourth, due to the existence of MOV's inherent characteristic voltage ratio, its residual transmission voltage is high, and single-stage lightning protection cannot guarantee the overvoltage protection requirements of electronic equipment, and it is generally used in In the second-level, third-level, and fourth-level lightning protection boxes, it brings inconvenience to installation and increases the cost

[0010] Fifth, since MOV is a zinc oxide ceramic structure, its overcurrent capability is proportional to its cross-sectional area, but the larger the cross-sectional area, the easier it is to deform during its firing process. Generally, the current-carrying capacity above 40KA8 / 20μS current wave is difficult to enlarge

[0016] However, this structure has the following disadvantages: the glow voltage is only 70V, the arc voltage is only 30V when the current is 100A

After the overvoltage, the power supply system will provide a huge short-circuit current to the single-gap metal-ceramic gas discharge tube to generate high-temperature thermionic emission. At the same time, due to the power factor problem of the AC power system, the current and voltage are not synchronized, so that the single-gap metal-ceramic gas discharge tube Cannot shut down automatically after the power supply voltage crosses zero

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