When the current flows through the conductor, there is a certain resistance to the conductor, so the conductor will heat up. and calorific value follows this formula: Q=0.24I2RT; where Q is calorific, 0.24 is a constant, I is the current flowing through the conductor, R is the resistance of the conductor, and T is the time at which the current flows through the conductor; It is not difficult to see the simple principle of the fuse, according to this formula. When the fuse material and its shape are determined, the resistance R is relatively determined (if its resistance temperature coefficient is not taken into account). As the current flows through it, it heats up and its calorific value increases over time. The size of the current and the resistance determines the speed at which the heat is generated, the structure of the fuse and the condition of its installation determine the rate of heat dissipation, and the fuse will not fuse if the rate of heat generated is less than the rate of heat dissipation. If the rate of heat generated is equal to the rate of heat dissipation, it will not fuse for a long time. If the heat is generated faster than the heat dissipation rate, then the heat generated will be more and more. And because it has a certain specific heat and quality, the increase in heat is reflected in the temperature rise, when the temperature rises to the fuse melting point above the fuse has been fused. That's how the fuse works. We should know from this principle that you must carefully study the physical properties of the material you choose when designing and manufacturing fuses, and ensure that they have a consistent geometric size. These factors play an important role in the normal operation of the fuse. Again, when you use it, be sure to install it correctly.