What harm does electromagnetic interference cause to humans?
The most harmful to humans by electromagnetic interference is actually the earth we live in, and lightning interference is the most harmful to human life. Lightning not only poses a great threat to human survival, but also causes great damage and damage to trees, forests, houses, buildings, and electrical equipment. At present, there is no effective way to design electromagnetic compatibility EMC circuits. Just like designing an amplifier, the amplification factor of the amplifier can be accurately calculated to within a few percent. The main method of designing electromagnetic compatibility EMC is to rely on experience or the experience of others to continue to improve. This book provides an in-depth analysis of electromagnetic interference electromagnetic compatibility, which is an indispensable basic reading for engineers' electronic design.
According to statistics, there are more than 100 lightnings per second in the Earth. The energy generated by each lightning can be lit up by a 100-watt bulb for 3 months. In the rainy season, one person is hit by lightning every 6 minutes. Thousands of people were killed by lightning strikes, and large areas of forests were hit by fire and lightning. Lightning also often caused high-voltage power grids and communication failures, disrupting city power and communications, causing urban traffic. There is chaos out of control; even the Buckingham Palace in Britain has suffered severe damage from lightning. In the 1950s, Buckingham Palace was burned by lightning strikes on a curtain cloth; Shanghai TV station suffered an average of 33 large lightning strikes per year. Lightning strikes will cause electronic equipment to suffer different degrees of damage; on June 22, 1992, several computer interfaces of the Beijing National Meteorological Center were destroyed due to inductive lightning strikes, and lost more than 20,000 yuan; on August 23, 1992, 60% of Zhangzhou City Cable TV and 50% closed-circuit television have been struck by lightning, 91 of which were destroyed by lightning strikes; on June 9, 2006, a large passenger plane in South Korea was caught in the air. Suddenly, the head disintegrated and fell off. Fortunately, there were no casualties.
The most effective way to suppress electromagnetic radiation interference is to shield the electromagnetic field, use a conductor to cut off the power line between the two charged bodies, or shield the object that generates the disturbing magnetic field with a magnetic material with high magnetic permeability. However, the conductor used for electric field shielding needs good grounding to be effective. If the conductor shielding the electric field is not well grounded, the conductor shielding the electric field will not only have no shielding effect, but will have the effect of relaying the electric field radiation interference, because the electric field will also pass. Induction causes the shielded conductor to be charged. In addition, shielding the magnetically induced interference with a conductor can also have an unexpected effect. Because the magnetic flux passes through the conductor, it also produces an induced current, namely: eddy current. The eddy current generates a magnetic field. The direction of the newly generated magnetic field is exactly opposite to the direction of the disturbing magnetic field, and the two can cancel each other out.