A fuse is an electrical component installed in a circuit to ensure the safe operation of the circuit. When the circuit is faulty or abnormal, the current will continue to rise. And the increased current may damage some important or valuable devices in the circuit, but also may burn the circuit or even cause a fire. If the fuse is correctly placed in the circuit, then the fuse will fuse itself to cut off the current when the current is abnormally raised to a certain height and a certain time, thus playing a role in protecting the safe operation of the circuit.
The role of the fuse
1. under normal circumstances, the fuse is to connect the circuit.
2. in the case of abnormal (overload), as a safety protection element in the circuit, the fuse cuts off and protects the circuit through fusing itself.
How fuses work
When the fuse is energized, the heat converted by electrical energy causes the temperature of the meltable to rise. When the normal working current or the allowed overload current passes through, the generated heat radiates to the surrounding environment through the meltable and the outer shell, and the heat emitted by convection and conduction gradually reaches a balance with the generated heat. If the heat generated is greater than the heat emitted, the excess heat will gradually accumulate on the meltable, making the meltable temperature rise; When the temperature reaches and exceeds the melting point of the meltable, the meltable will melt, fuse and cut off the current, which plays the role of safety protection circuit.
Factors affecting fuse life
1. Working environment temperature: High ambient temperature will damage the life of the fuse.
2. Pulse current: The fuse will gradually age with the increase of pulse energy and frequency.
3. Others: For example, the pipe clamp in contact with the fuse, the length of the connecting wire, and the cross-sectional area
Effects of aging fuses on use
Even if the fuse is aged, there is no danger that the current that should be cut off will not blow. After the fuse aging, it is equivalent to a decrease in the rating (current) rather than an increase. So there is no safety problem in the circuit, but it will cut off the circuit under a small overload current or pulse.
