Introduction to Shielded Cables

1. The so-called shielded cable is a special type of cable that shields and insulates around the cable to reduce electromagnetic interference (EMI). Shielded cables can allow external electromagnetic radiation and magnetic field radiation to directly enter the ground without causing interference to the inner wires. Generally, shielded cables have two layers of shielding, with mesh like braided wires used to prevent magnetic field radiation, and aluminum foil layers mainly used to prevent electromagnetic radiation. The shielding layer must be grounded in order to have a good shielding effect. When the high-frequency electromagnetic field from the outside passes through the shielding layer, it will generate eddy currents and be lost.

2. Shielded cable is a special type of cable with a mesh braided wire added to the outer layer of the cable. Cable shielding refers to the fact that the outer mesh braided wire of the cable has been grounded at a single end, allowing external electromagnetic and magnetic radiation to directly enter the ground without causing any interference to the inner wires. A better shielded cable usually has two layers of shielding. The mesh braided wire is used to prevent magnetic field radiation, and the aluminum foil layer is used to prevent electromagnetic radiation. Generally, coaxial cables for cable TV should be used, and leads from the frequency converter to the motor should be used. In areas with interference, the power supply should also be shielded, and analog leads should also be used.

3. Shielded cables are required to resist interference and prevent external electromagnetic fields from entering the circuit. Generally, shielded cables are used for circuits with higher frequencies and lower signal levels. The most common type is cable television coaxial cable, which, in addition to the inner conductor, usually has a layer of metal mesh on the outside for shielding, and is also one of the signal circuits. The core wire of communication cables, excluding copper conductors, is wrapped with a layer of aluminum foil and grounded to provide shielding.

How should shielded cables be prevented from damage?

1. Choose products with reasonable shielding layer weaving angle

In the process of producing cable shielding layer, if its processing technology is not standard, the weaving angle of the shielding layer will be set unreasonably, causing cable tension load and damage to the shielding layer. Therefore, in order to prevent damage to shielded cables, it is necessary to first choose a suitable shielding layer, such as a armored extruded sheath.

2. Add a protective layer to the shielding layer

If there is a problem with the internal structure of the shielding layer, we generally cannot observe it directly with the naked eye. But if a sheath is added to the shielding layer, it is equivalent to adding a layer of protection to the cable, which can prevent damage to the shielding cable.