To maintain operational stability, electronic components are often packaged with a synthetic Resin dispensing to improve insulation and protection from the environment. The element may be passive or active: Passive components are electronic components that do not have any gain or directionality when used. In Network analysis, they are referred to as Electrical elements. Active components are electronic components that have gain or directivity when in use as opposed to passive components. They include semiconductor devices and vacuum tubes.

Components are not consumed A tube, no matter how good, will gradually deteriorate due to changes in cathode atoms and chronic leakage. For technical reasons, the same problem existed at the beginning of transistor fabrication. With the progress of material production and various improvements, the life of transistors is generally 100 to 1000 times longer than that of electronic tubes, which is worthy of the reputation of permanent devices.

The five major characteristics of semiconductors: resistivity characteristics, conductivity characteristics, photoelectric characteristics, negative resistivity temperature characteristics, rectification characteristics. In semiconductors that form a crystal structure, specific impurity elements are artificially doped, and the electrical conductivity is controllable. Under the conditions of light and thermal radiation, its electrical conductivity changes significantly.

Classification of volt-ampere characteristics For most conductors, at a certain temperature, the resistance remains almost unchanged and has a certain value, and this type of resistance is called a linear resistance. The resistance of some materials varies significantly with current (or voltage), and its volt-ampere characteristic is a curve.