Wirewound resistors are a type of fixed resistors. Wirewound resistors are made of resistance wire wound on an insulating skeleton. The resistance wire is generally made of nickel-chromium, manganese-copper and other alloys with a certain resistivity. The insulating skeleton is made of ceramics, plastics, metals coated with insulating layers and other materials into tubular, flat and other shapes. The resistance wire can be wound with one layer or multiple layers on the skeleton according to the needs, or the non-inductive winding method can be used. Wirewound resistors are mainly used as voltage dividers, step-downs, current shunts and load resistors in AC and DC circuits such as precision instruments, telecommunication instruments, and electronic equipment.