Understanding the working mechanism of fuses is the prerequisite for correct fuse matching design. To fully understand the working mechanism of the fuse, you only need to understand two questions: one is why a fuse is added to the circuit, and the other is how the fuse protects the circuit.
Why is a fuse added to the circuit? If there is no fuse in the line, then once the circuit is overloaded or a short circuit occurs, the current in the loop will inevitably increase, so that when the current flowing through the wire exceeds the carrying current of the wire, the wire will overload and heat up, melting the wire insulation layer and copper wire , or even spontaneous combustion, causing safety accidents (car burning).
After clarifying the causes and consequences of the spontaneous combustion of the wire, it is necessary to ask, how to avoid the problem of the spontaneous combustion of the wire?
The fuse is produced in such a situation. In order to avoid the spontaneous combustion of the wire, we hope that there is a component that can detect the overcurrent and short-circuit current in the circuit before the wire burns, and can respond quickly to interrupt the circuit quickly. (fuse blown), so as to achieve the purpose of protecting the wire.