Saturday, December 18, 2010
【 Weak current College 】 Resettable fuse 】
We all know, traditional one-time insurance component once burned, it must be replaced. The Resettable fuse in current circumstances can be automatically cut off the high-current, when an exception after large current exclusions, automatic recovery, do not need artificial restoration or replacement, this gives users a great convenience. Resettable fuse with overcurrent and overtemperature two protection function, and can be reused, applies to all need over-current and over-temperature protection. Working principle: Resettable fuse is made from polymer and conductive material, etc, so it is known as aggregation switch. In a normal state, into the crystalline structure of polymers, polymer conductive materials through conductive channel, consisting of three dimensional is low on-State resistance. Because of the low-impedance, normal current flowing through the components of the heat generated is small, does not make changes in the crystalline structure. When there are large current through or overcurrent, Resettable fuse itself temperature rise rapidly, the symbol of the heat that polymer is expanding, causing conductive material chain fracture resistance of the components in a very short period of time may be increased to the original resistance of a million times over, stop the current flows through the symbol, only small current to flow, such as cut off circuit, reach the purpose of protection. When an exception after large current exclusion or overheating elimination, the conductive chain component has re-established, a symbol back to their normal state of low resistance.