The shielded wire is a transmission wire harness that uses conductive cloth and mesh braided wire to wrap the signal wire harness.
Introduction: A wire wrapped with a conductor outside the wire is called a shielded wire.
Structure: The wrapped conductor is called the shielding layer, which is generally a conductive cloth, braided copper mesh or copper (aluminum).
Application: The shielding layer needs to be grounded, and the external interference signal can be led to the ground by this layer to avoid the interference of the interference signal into the inner conductor and reduce the loss of the transmission signal.
Notes for use:
The shielding layer of the shielding wire does not allow multi-point grounding, because different points of contact are always different, and there is a potential difference between each point. For example, multi-point grounding can generate current in the shield layer, induce current on the wire and induce interference on the signal wire. It does not play a shielding role, but introduces interference, especially in occasions when frequency converters are used a lot. The interference contains various high-order harmonic components, causing greater influence, so special attention should be paid.
When the transmission distance of the signal wire is relatively long, due to the different grounding resistance of the two ends or the current on the PEN wire, the potential of the two grounding points may be different. At this time, if the two ends are grounded, the shielding layer will have a current flow, but the signal Interference is formed, so in this case, a point of grounding is generally adopted, and the other end is suspended to avoid the formation of such interference.