Everyone knows that copper is a metal that exists in th […]
Everyone knows that copper is a metal that exists in the earth's crust and oceans. The content of copper in the earth's crust is about 0.01%. In individual copper deposits, the content of copper can reach 3% to 5%. Most of copper in nature exists as a compound or copper mineral. Copper minerals and other minerals are aggregated into copper ore, and the mined copper ore becomes a copper concentrate with a higher copper grade after beneficiation.
Copper is mainly used in the field of electrical and electronic industries to manufacture wires, communication cables and other finished products such as motors, generator rotors and electronic instruments, meters, etc., which accounts for about half of the total industrial demand. Copper and copper alloys play an important role in computer chips, integrated circuits, transistors, printed circuit boards and other equipment devices. For example, chromium zirconium copper alloy with high electrical conductivity and high thermal conductivity is used for transistor leads. Recently, the internationally renowned computer company IBM has replaced copper in silicon chips with aluminum. This shows that copper plays an important role in the electrical and electronic industries.
Is there a difference between high-precision copper tape shielding and copper wire shielding
1. High-precision copper tape shielding is mainly used for cables, and its bending resistance is poor; copper wire shielding is mainly used for electrical equipment with frequent bending and excellent bending performance.
In other words: copper tape shielding and copper wire shielding have the same reason, except that when the conductor cross section is greater than 500 in 10kV and below cables, it is recommended to use copper wire shielding as much as possible. If copper tape shielding is used, the thickness of the copper tape needs to be increased. According to the conditions of cable laying, if it is necessary to carry a large short-circuit current, it is recommended to use copper wire shielding
2. The difference between high-precision copper tape shielding and copper wire shielding is the ability to carry short-circuit current. Copper wire is slightly larger.
3. The coverage density of high-precision copper tape reaches 100%, and the shielding effect is better than that of copper wire braid.
The best shielding effect belongs to the two structures of "one layer braid / aluminum foil / one layer braid" and "one layer braid / semiconductive layer / one layer braid", but the cost is relatively high. Ordinary cables are designed according to Ohm's law. Strictly speaking, digital communication cables must be designed according to the transmission line equation! In high-speed, long-line transmission, such as: PLC, I / O, RS485 / 422, DCS, Ethernet, FF, CAN, PROFIBUS, Devicenet, Lon-works, etc. Use special cables!
When the cables transmitting weak signals are laid together with the cables transmitting strong electricity, and unconditionally maintain a sufficient distance, double or multi-layer shielded cables should be used! It is recommended to use steel tape armored outer sheathed cables to prevent rat bites Injury, it can increase the magnetic shielding, which is more conducive to direct buried laying!