The fuse is generally composed of three parts: one is the melt part, which is the core of the fuse. It acts to cut off the current when it is blown. The melt of the fuse of the same type and the same specification has the same material, the same geometric size, and the resistance value. As small as possible and consistent, the most important thing is that the fuse characteristics should be consistent, the household fuse is usually made of lead-bismuth alloy; the second is the electrode part, usually two, it is an important part of the melt and circuit connection, it must have good Good electrical conductivity should not produce obvious contact resistance; third is the bracket part, the fuse of the fuse is generally slender and soft, the role of the bracket is to fix the melt and make the three parts into a rigid whole for easy installation and use. It must have good mechanical strength, insulation, heat resistance and flame retardancy, and should not cause breakage, deformation, burning and short circuit during use.