How does a resettable fuse work?
The resettable fuse is composed of specially treated polymer and carbon black distributed inside.
Under normal operation, polymers tightly bind conductive particles outside the crystal structure, forming a chain like conductive pathway. At this point, the resettable fuse is in a low resistance state, and the heat generated by the current flowing through the resettable fuse is minimal and will not change the crystal structure.
When the circuit is short circuited or overloaded, the large current flowing through the resettable fuse will cause the polymer to melt, and the volume will rapidly increase, forming a high resistance state. The working current will rapidly decrease, thereby limiting and protecting the circuit.
After the fault is eliminated, the reset fuse can cool down and crystallize again. The volume is reduced, and the conductive particles form a conductive path again. The reset fuse can be restored to a low resistance state, thus completing circuit protection without the need for manual replacement.
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