A carbon resistor (CCR) consists of a solid cylindrical resistor element with an embedded lead and a metal end. The lead is connected to the lead. The resistor body is protected with paint or plastic. Carbonaceous resistors of the early 20th century had non-insulators; The leads are wound around the ends of the resistance element and welded. Color code the finished resistor by resistor value.
Resistance elements are made from a mixture of fine powdered carbon and insulating material, usually ceramic. Resin binds the mixture together. The resistance value is determined by the ratio of the filling material (ceramic powder) to carbon. Higher concentrations of carbon, which is a good conductor, will have lower resistance. Carbon resistors came into use in the 1960s and early years, but other types of resistors have better properties, such as tolerance, voltage dependence, and stress, and are now less commonly used. When carbon exceeds voltage stress, the resistance value of carbon component will change.In addition, if the carbon resistor is exposed to moisture for a period of time, the moisture in the resistor will increase significantly, and the welding heat will cause an irreversible change in the resistor value. Carbonaceous resistors have poor stability over time, so factory classification has a maximum tolerance of only 5%. These resistors are non-inductive and have excellent advantages when used for voltage pulse reduction and surge protection applications.