A safety varistor

Abstract

The invention discloses a safe varistor. The safe varistor comprises a varistor and a flame retardant and anti-explosion shell arranged outside the varistor. The safe varistor is characterized in that the lower half part of the outer side of a cover is provided with a bayonet; the inner side of a groove in the top of the shell is provided with an annular groove which can be mutually buckled with the bayonet of the cover to a whole body; the bottom of the groove in the top of the shell is provided with a shaft hole, an air discharging hole, an air discharging groove and a shaft positioning column; in addition, the top inside the shell is provided with two cylindrical positioning blocks; and on the upper part of the groove in the shell, a shaft extends to the inner part along the shaft hole and is buckled with a spring and a gasket to a whole body. As a spring-type automatic air discharging device is adopted, when an explosion happens, the pressure inside the shell is raised, the air discharging device is automatically opened, and high pressure air is discharged out of the shell, and thus the shell is prevented from deforming or rupturing; and when the air is discharged completely and the pressures inside and outside of the shell are same, the air discharging device is automatically closed to prevent moisture and corrosion, and thus the service life of a product is prolonged effectively.

Description

technical field [0001] The invention relates to an electronic component, in particular to a safety piezoresistor, belonging to the technical field of piezoresistor preparation. Background technique [0002] With the continuous development of electronic information technology, varistors are widely used in various low-voltage equipment such as communication equipment and electrical appliances. Under abnormal overvoltage, the varistor can effectively protect low-voltage equipment because its own resistance value changes nonlinearly with the applied voltage. At present, the packaging structure of safety varistors can be roughly divided into four categories: one is the self-explosion-proof design structure, such as patent CN101620901A, this type of design and manufacturing process is complicated, and the production cost is high; the other is safety explosion-proof structure with fuse. Designs, such as patents CN 2457706Y, CN101079341A, etc. Once this type of design is hit by a l...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a safety varistor, which is designed by adopting a spring type automatic exhaust device to prepare a safety varistor with safe structure, convenient processing, good moisture-proof and anti-corrosion performance, and suitable for mass industrial production The device overcomes the deficiency of the existing technology that the high-pressure gas cannot be discharged well after the high-pressure gas is generated in the piezoresistor housing

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