Working principle of patch self-recovery fuse

BUSSMANN self-recovery fuse

Working principle of patch self-recovery fuse:

The patch resettable fuse is composed of specially processed polymer resin and conductive particles distributed in it. Under normal operation, the polymer resin tightly binds the conductive particles outside the crystalline structure to form a chain-like conductive electrical path. At this time, the recoverable fuse is in a low resistance state (a), which is generated by the current flowing through the resettable fuse on the line The heat energy is small and will not change the crystal structure. When the circuit is short-circuited or overloaded, the heat generated by the large current flowing through the self-recovery fuse melts the polymer resin, and the volume increases rapidly to form a high-resistance state (b), and the operating current decreases rapidly, thereby limiting and protecting the circuit. When the fault is eliminated, the PTC can recover the fuse to re-cool and crystallize, the volume shrinks, the conductive particles re-form a conductive path, and the self-recoverable fuse returns to a low resistance state, thus completing the protection of the circuit without manual replacement.

Scope of application

Communication equipment: program-controlled exchanges, user terminal equipment, general distribution security units, etc.

Automotive electronics: automotive wiring harnesses, automotive anti-theft devices, automotive micro-motors, automotive electronic products, etc.

Electronics industry: power supply ballasts, micro motors, fire alarms, instruments and meters, etc.

Electrical equipment: satellite receivers, security equipment, speakers, industrial automatic controls, etc.