A brief introduction to the working principle of fuses

What is fuse？

        The fuse is an electrical component installed in the circuit to ensure the safe operation of the circuit,and the IEC127 standard defines it as a "fuse-link".

How does the fuse work？

     We know that when the current flows through the conductor, the conductor will generate heat due to the existence of a certain resistance in the conductor, and the calorific value follows the formula: Q=0.24I²RT; where Q is the calorific value, 0.24 is a constant, and I is the flow through the conductor The current of the conductor, R is the resistance of the conductor, and T is the time for the current to flow through the conductor; therefore, the material of the fuse and its shape are determined, and the resistance of the fuse is relatively determined without considering the effect of temperature on the resistance of the material .

    When current flows through the fuse, it heats up due to the resistance of the fuse, which also increases over time. The magnitude of the current and resistance determines the speed at which the fuse generates heat, and the structure of the fuse and the state of its installation determine the speed of heat dissipation. Different state changes occur.
    If the rate at which heat is generated is less than the rate at which it is dissipated，the fuse will not blow.
    If the rate at which heat is generated is equal to the rate at which heat is dissipated, it will not fuse for a considerable period of time.
    If the rate of heat generation is greater than the rate of heat dissipation, more and more heat will be generated, because it has a certain specific heat and mass, and the increase in heat is reflected in the increase in temperature. The fuse blows when it reaches the melting point of the fuse. This is why a fuse protects the circuit.

How to choose the fuse？
    Conclusion: We know from how fuses work that the physical properties of selected materials must be carefully studied when designing and manufacturing fuses, and to ensure that they have consistent geometry. Because these factors play a crucial role in whether the fuse can work normally. Also, when in use, it must be installed correctly.