Functions of Shielded Computer Cables
Computer cables are suitable for fixed connections in computers, testing instruments, and meters with AC rated voltages of 300/500V and below, requiring high anti-interference performance. Product Standard: Enterprise Standard Model Name: DJYVP2 Twisted-Pair Polyethylene Insulated, PVC Sheathed, Copper Tape Wrapped, Shielded, Steel Tape Armored Cable for Computers. DJYVP Twisted-Pair Polyethylene Insulated, PVC Sheathed, Copper Tape Wrapped, Shielded Cable for Computers.
The long-term allowable operating temperature of the cable conductor should not exceed 70°C. During use, the cable should be protected from high-temperature DC radiation or contact. The ambient temperature during cable installation should be no less than 0°C. The allowable bending radius during cable installation is: for unarmored cables, no less than 6 times the cable's outer diameter; for armored or shielded cables, no less than 12 times the cable's outer diameter; for shielded flexible cables, no less than 6 times the cable's outer diameter. The role of computer shielded cables:
I. The main causes of interference
(1) Interference introduced by resistive coupling
(2) Interference introduced by capacitive and inductive coupling
(3) Interference introduced by the computer power supply line
(4) Interference introduced by lightning strikes Note:
1. Electrostatic interference caused by capacitive coupling between wire cores due to external voltage;
2. Electromagnetic induction interference caused by current. Generally speaking, when there is a high voltage or high current interference source nearby, the electrical interference is more serious. Since the distance between the wire cores of the same cable is small, the interference level is much greater than that of adjacent cables laid in parallel.
II. Shielding selection
1. For switching signals, a total shield can be used;
2. For high-level analog signals, a total shield of twisted cores is suitable, and if necessary, separate shielding of twisted cores can also be used;
3. For low-level analog signals or pulse signals, separate shielding of twisted cores is suitable, and if necessary, a composite total shielding containing separate shielding of twisted cores can also be used. 3. The function of shielded cables: Shielded cables are mainly used to prevent interference caused by (1) electrostatic interference, (2) electromagnetic induction, and (3) crosstalk induction, ensuring the normal operation of system transmission.
