Two-section type over-temperature self-recovery device

Abstract

The invention relates to the field of electrical self-recovery equipment, and particularly relates to a two-section type over-temperature self-recovery device. The two-section type over-temperature self-recovery device comprises a first conductive part, a second conductive part, a third conductive part and a fourth conductive part, wherein the third conductive part is made of a conductive materialof which the temperature is in direct proportion to the resistance value and is arranged on the first conductive part, the fourth conductive part is made of a material with a large thermal expansioncoefficient and is arranged between the third conductive part and the fourth conductive part, and the first conductive part and the second conductive part abut against each other when the fourth conductive part is in a normal state and are expanded and separated when the fourth conductive part is in a thermal expansion state. Compared with the prior art, the beneficial effects of the invention arethat the first conductive part and the second conductive part form a first conduction branch, a constant low-resistance and low-power-consumption working state is maintained, and when the temperatureis higher than a critical temperature, a second conduction branch is switched, thereby achieving a high-resistance circuit, reducing the size of a current, and facilitating the reduction of the temperature.

Description

technical field [0001] The invention relates to the field of electrical self-recovery equipment, in particular to a two-stage over-temperature self-recovery device. Background technique [0002] In communications and networks, computers and multimedia, batteries and portable electronic products, industrial switching power supply networks, automobiles, etc., high molecular polymer (PPTC) resettable fuses are usually used for overcurrent protection. [0003] PPTC is made of high-molecular organic polymers under the conditions of high pressure, high temperature, and vulcanization reaction, after adding conductive particle materials, and then processing them through a special process. At room temperature, when the normal working current passes through the inside of PPTC, the high-molecular polymer and the conductive particle material are combined with high density to form a crystalline structure. At this time, it is in a low-resistance molecular state, and the normal internal re...

AI Technical Summary

Problems solved by technology

[0005] It can be seen from the above that when the temperature is lower than the critical value of the protection temperature, due to the positive temperature coefficient of the material, the resistance will continue to rise, resulting in loss

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