Restorable fuse, also known as self-restoring fuse, is composed of polymeric resin and conductive particles distributed in it. Under normal working environment, the conductive particles are tightly bound outside the crystal structure by the polymeric resin, forming a chain-type conductive circuit. At this time, the recoverable fuse is in a low resistance state. In this state, the heat energy generated by the recoverable fuse current is very small, and the crystal structure will not be changed. When the line is short-circuited or overloaded, the heat generated by the large current flowing through the recoverable fuse melts the polymer resin, and the volume increases rapidly, forming a high resistance state, and the working current decreases rapidly, thus limiting and protecting the circuit. After troubleshooting, the fuse can be restored to cool the crystal again, the volume shrinks, the conductive particles re-form the conductive path, and the fuse can restore the low resistance. Compared with the traditional fuse, the recoverable fuse has the advantages of automatic recovery, small size and stronger.
Working principle of recoverable fuse.
The recoverable fuse elements are connected in series in the circuit, and are in a low resistance state under normal conditions, thus ensuring the normal operation of the circuit. When the circuit is short-circuited or enters an abnormally large current, the self-heating of the element increases the impedance, limits the current to a small enough value, and plays the role of overcurrent protection. At the same time, when the external environment temperature rises sharply and the environment reaches the product switching temperature, it can play the role of over-temperature protection.
Recoverable fuse advantage.
(1) when the fault of overcurrent and overheating is eliminated, the fuse element can automatically return to the low resistance state. This not only avoids maintenance and replacement, but also avoids the open and close state of continuous cycle which may cause circuit damage. The recoverable fuse is made of polymer and conductive material. The recoverable polymer fuse consists of a polymer resin matrix and conductive particles distributed therein. Under normal circumstances, the conductive particles form chain-like conductive paths in the resin matrix, and the polymer can restore the low impedance of the fuse. When overcurrent occurs in the circuit, the polymer flowing through the circuit can recover the heat generated by the large current of the fuse, expand the volume of the polymer resin matrix, and cut off the chain-shaped conductive path formed by the conductive particles, so that the polymer can recover the rapid increase of the fuse impedance, thus protecting the circuit from overcurrent.
(2) Within a few seconds after the overcurrent condition of Kimberley Process Certification Scheme components disappeared, the temperature of JKPPTC components dropped rapidly and JKPPTC components recovered rapidly.
(3) The higher the ambient temperature, the greater the current passed. The shorter the action time, the lower the current speed of the recoverable fuse when the ambient temperature exceeds 25℃. When the ambient temperature is 25℃, 100% of the current on the line passes through the recoverable fuse, but if more than twice the rated current is generated, the fuse can be recovered.
Recoverable fuse application.
Communication equipment field: SPC exchange, user terminal equipment, general wiring security unit, etc.
Automotive electronics: automotive wiring harness, automotive burglar alarm, automotive micromotor, automotive electronic products, etc.
Electronic industry: power ballast, micromotor, fire alarm, instrumentation, etc.
Electrical equipment field: satellite receiver, security equipment, loudspeaker, industrial automatic control, etc.
Restorable fuse with non-polarity, small capacitance, suitable for acre and DC power supply, connected in series with the protected electric appliance on the line. Lithium-ion batteries often burn and explode due to short circuit or overcharge. Restorable fuses can effectively protect them.
