Overvoltage protection device

Abstract

The invention relates to an overvoltage protection device, which comprises a shell,, a moving electrode and a fixed electrode, wherein a metal oxide voltage-dependent resistor which is arranged in the shell is provided with two opposite main body surfaces and four side surfaces, and the area of each main body surface is larger than the area of any side surface; one end of the moving electrode is installed on the shell; and one end of the fixed electrode is connected with the metal oxide voltage-dependent resistor and the other end of the fixed electrode is connected with the other end of the moving electrode through welding. The fixed electrode is arranged relative to the metal oxide voltage-dependent resistor and on the projection of the main body surface perpendicular to the metal oxide voltage-dependent resistor. One end of the fixed electrode which is connected with the moving electrode is arranged outside the main body surface. A welded part between the fixed electrode and the moving electrode is not adversely affected by the heating up of a metal oxide varistor (MOV).

Description

technical field [0001] The present invention relates to a circuit protection device, more particularly, to an overvoltage protection device. Background technique [0002] With the promulgation and implementation of a series of national standards GB18802.1-2002, GB50057, GA173 and other standards, the lightning protection regulations in various places are becoming more and more perfect, and the application of overvoltage protection devices, also known as surge protectors (SPDs), is increasing. more popular. The overvoltage protection device can protect the load in the circuit so that it can withstand the impact of instantaneous overvoltage or lightning current. More specifically, the overvoltage protection device is generally connected in parallel with the load and installed upstream of the load. When the circuit is operating normally, the overvoltage protection device is in a high-impedance state, which does not affect the normal operation of the load; or lightning current...

AI Technical Summary

Problems solved by technology

Such a design has at least the following disadvantages: During normal use, since the static electrode is closer to the main surface of the MOV, the heat generated on the main surface of the MOV will be easily conducted or radiated to the static electrode, and then transferred to the static electrode and the moving electrode. between the low temperature solder, thus affecting the joint strength of the solder

However, face-to-face welding is not only inconvenient, but also easily causes air holes and virtual welding.

Porosity and / or virtual welding will increase the risk of electric power and arcing in the weld, which will cause the above-mentioned disadvantages that affect the reliability, safety and service life of the SPD

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