normally closed vs normally open_mini cooper fuse box factory

12 2024-09

　　Fuse resistance

　　In addition to protecting the circuit, fuses themselves also have a certain resistance in the circuit.

　　From the essence of resistance, the resistance of a fuse is determined by factors such as the conductivity, length, and cross-sectional area of its material. Generally speaking, the resistance of a fuse is relatively small, so that when normal current passes through, the voltage drop generated at both ends is small and will not have a significant impact on the normal operation of the circuit.

　　In terms of materials, the resistivity of different materials varies. For example, the resistivity of materials such as lead tin alloys mentioned earlier determines the size of the fuse resistance. If it is a material with high electrical resistivity, the resistance of the fuse will be higher at the same length and cross-sectional area.

　　From the perspective of length factor analysis, according to the law of resistance, under the same material and cross-sectional area, the longer the length of the fuse, the greater its resistance. When designing a fuse, adjusting its length can affect its resistance value.

　　The cross-sectional area is also a key factor, the larger the cross-sectional area, the lower the resistance. This is because thicker fuses can provide more conductive channels and have less obstruction when current passes through.

　　Fuse resistance has a certain significance in circuits. Under normal operating current, its resistance causes it to consume a certain amount of power, but this power is small and will not cause excessive temperature rise. However, when the current is too high, due to the presence of resistance, the power consumed by the fuse will increase sharply, and the heat generated will cause the fuse to quickly heat up, reaching the melting point and then melting, thereby cutting off the circuit.