shield of shielded cable

The wire and cable industry is the second largest industry in China after the automobile industry, and the product variety satisfaction rate and domestic market are both over 90%. Worldwide, the total output value of China's wire and cable has surpassed that of the United States, becoming the world's largest wire and cable producer. With the rapid development of China's wire and cable industry, the number of new companies continues to rise, and the overall technical level of the industry has been greatly improved.

The continuous and rapid growth of China's economy has provided a huge market space for cable products. The strong temptation of the Chinese market has made the world focus on the Chinese market. In the short decades of reform and opening up, China's cable manufacturing industry has The huge production capacity formed has impressed the world. With the continuous expansion of China's electric power industry, data communication industry, urban rail transit industry, automobile industry, shipbuilding and other industries, the demand for wires and cables will also grow rapidly, and the wire and cable industry has huge development potential in the future.

The shielding layer of the shielded cable cannot be grounded repeatedly, and two methods are usually used: single-end grounding of the shielding layer and double-end grounding of the shielding layer.

1. Double-ended grounding is to connect both ends of the metal shielding layer of the shielded cable to the ground.

In the case that the shielding layer is grounded at both ends, the metal shielding layer will not generate an induced voltage, but the interference magnetic flux of the metal shielding layer will cause a shielding circulating current to pass through.

2. The single-end grounding of the shielding layer means that the metal shielding layer is directly grounded at one end of the shielded cable, and the other end is not grounded or is grounded through protection.

In the case of single-end grounding of the shielding layer, there is an induced voltage between the metal shielding layer of the non-grounded end and the ground, and the induced voltage is proportional to the length of the cable, but the shielding layer has no potential circulating through. Single-ended grounding is to use the suppression potential difference to achieve the purpose of eliminating electromagnetic interference.

This grounding method is suitable for short-length lines, and the induced voltage corresponding to the cable length cannot exceed the maximum voltage. The existence of electrostatic induced voltage will affect the stability of the circuit signal, and may sometimes form an antenna effect.