The role of the shielded wire is to isolate the electromagnetic field noise source and sensitive equipment, cutting off the propagation path of the noise source. Shielding is divided into active shielding and passive shielding, the purpose of active shielding is to prevent the noise source outward radiation, is the shielding of the noise source; passive shielding is designed to prevent sensitive equipment from being interfered by the noise source, is the shielding of sensitive equipment.
Why is wire shielding used?
Shielding can be shielded by this electromagnetic field in the cable, can also play a certain protective role, if the cable core wire damage occurs, the leakage of current can flow along the shielding layer into the ground network, play a role in safety protection. Control cable shield role: there is no difference between other, but in many places, especially computer system control cables, where the shield is used to shield external influences, because its own current is very weak, very afraid of the external electromagnetic field effect. Shielded cable grounding is to prevent magnetic field interference.