What is EMC

Electrical equipment that can function normally in the presence of electromagnetic influences from other operating electrical equipment, without itself having harmful effects either on the environment or on the operation of said electrical equipment — such equipment is electromagnetically compatible (both with the environment and and with others working near electrical appliances).

What is EMC

Recently, developers pay special attention to the issue of electromagnetic compatibility (abbreviated EMC) of devices with their own components and assemblies, since semiconductor microcircuits are the most susceptible to electromagnetic interference. The effect of disturbances can be conductive (in the form of current induction) or radiative (in the form of field interaction).

In this context, as far as the immunity of the equipment is concerned, radiated and conducted disturbances along the wires are taken into account, and the compatibility bandwidth may extend up to 400 GHz.On the territory of the Customs Union (Russia, Belarus, Kazakhstan), electromagnetic compatibility (norms and standards) is regulated by a special document - TR CU 020/2011.

Electromagnetic disturbances can have as their source either natural phenomena (for example, lightning discharges) or technical processes (for example, transient processes in circuits during fast periodic or random switching). In any case, interference implies a sudden change in voltage or current in a circuit that is undesirable, whether it travels along the cable or is transmitted in the form of an electromagnetic wave.

Electromagnetic compatibility

Wave interference, mutual interference of control and monitoring systems are all examples of electromagnetic interference that greatly interferes with devices working together. And the higher the voltage and current in the device, the stronger the interference. Developing conventional technology, designers try to achieve stable operation of the device in a general electromagnetic environment. Some special equipment must be able to withstand such harsh conditions, such as the electromagnetic radiation generated by a nuclear explosion.

In EMC theory, the terms "receiver" and "transmitter" of energy (interference) are used. Interference transmitters can be: broadcasting and television towers, electrical circuits and networks, etc. Interference receivers are: radio receivers, antennas, automation systems, automotive electronics, automation and relay protection, information processing systems, etc.

Some of the devices that can be sources of interference at one moment are already their receivers at another moment.Therefore, the electromagnetic compatibility of the device assumes such a nature of its operation when, as a transmitter, it creates interference, the level of which does not exceed the permissible value, and as a receiver, it is distinguished by a sufficiently high noise immunity.

In one way or another, electromagnetic compatibility is required for almost every piece of equipment today. Even in the most ordinary conditions of the modern city, there is a colossal number of different types of radiation, and if measures are not taken to maintain EMC, then the reliable and correct operation of many technical means will simply be impossible, because they will fail and cause reasons for systemic accidents, creating reversible or irreversible disorders.

EMC is always necessary for technical means as long as they exist: EMC is taken into account at the design stage of the device, EMC is provided during the commissioning of this device, EMC is maintained during its direct operation.

The most acute problem with electromagnetic compatibility is for organizations that are characterized by the following characteristics: a high power-to-weight ratio (for example, a power plant), increased requirements for the security of information systems (for example, a bank), an unfavorable typical electromagnetic environment around (for example, a manufacturing plant of electronics built in an area with high background radiation).

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