Principle and application of PPTC self recovery fuse

时间:2019-12-06 丨 预览:351 人次

PPTC resettable fuse is an overcurrent electronic protection component. It uses high molecular organic polymer under high pressure, high temperature and vulcanization reaction conditions. After adding conductive particles, special treatment is required. When the lamp reaches the end of its life, the recoverable fuse provides protection and provides transistor fault protection. Self-recovery fuses can be divided into two types: polymer polymer PPTC and ceramic CPTC. Self-recovery fuses are used in ballasts, transformers, speakers, etc.

PPTC自恢复保险丝

Principle of PPTC resettable fuse:

The self-recovery fuse consists of specially treated polymer resin and conductive particles distributed in it. Under normal operation, the polymer resin tightly bonds the conductive particles outside the crystal structure to form a chain-shaped conductive path. At this time, the resettable fuse is in a low resistance state, and the thermal energy generated by the current flowing through the resettable fuse on the wire is very small. No change in crystal structure. When the circuit is short-circuited or overloaded, the heat generated by the large current flowing through the resettable fuse will melt the polymer resin, increase the volume rapidly, form a high-resistance state, and rapidly reduce the operating current, thereby limiting and protecting the current circuit.

自恢复保险丝

PPTC resettable fuse resettable fuse application:

When the lamp reaches the end of its life, the recoverable fuse provides protection and provides transistor fault protection. Since the ballast is often failed due to the high transistor and low voltage switch, the fault protection of the transistor is of great significance. First, the self-recovery fuse has a self-recovery function, which can reduce the number of product repairs and services, thereby reducing costs. Secondly, the resettable fuse has a small size and takes up very little space on the circuit board, which is convenient for design.