How the fuse works

With the flow of current through a conductor, heat is generated due to the conductor's resistance. The calorific value of the conductor can be calculated using the formula Q=I2RT, where Q represents the calorific value, I is the current flowing through the conductor, R is the resistance of the conductor, and T is the time taken for the current to flow through the conductor. Based on this formula, we can easily understand how a fuse operates. Once the material and shape of the fuse are determined, the resistance R can be calculated. When the current flows through the fuse, it generates heat, causing the calorific value to increase with time. The rate at which heat is generated depends on the current and resistance, whilst the rate of heat dissipation depends on the structure and installation status of the fuse. If the heat dissipation rate is greater than the rate of heat generation, the fuse will not blow. If they are equal, the fuse will not blow for a prolonged period. However, if the rate of heat generation is greater than the rate of heat dissipation, the fuse will generate increasingly more heat, leading to a rise in temperature. Once the temperature surpasses the melting point of the fuse material, it will blow. This principle highlights the importance of carefully studying the physical properties and materials used in designing and manufacturing fuses, ensuring they have consistent geometric dimensions. Correct installation is also crucial in the safe operation of fuses.