Electromagnetic interference

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Electromagnetic interference (EMI) is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction. The disturbance may degrade the performance of the circuit or even stop it from functioning. EMI can be caused by natural sources such as solar flares and lightning, as well as by human-made sources like electronic devices, power lines, and radio transmitters.

Types of EMI

EMI can be classified into two main types:

• Conducted EMI: This type of interference is transmitted through physical contact with a conductor, such as a power line or a signal cable.
• Radiated EMI: This type of interference is transmitted through the air as electromagnetic waves.

Sources of EMI

EMI can originate from various sources, including:

• Natural sources: These include solar flares, lightning, and other atmospheric phenomena.
• Human-made sources: These include electronic devices, power lines, radio transmitters, and industrial equipment.

Effects of EMI

The effects of EMI can range from minor disturbances to complete system failures. Common effects include:

• Signal degradation: EMI can cause a reduction in the quality of the signal being transmitted.
• Data loss: EMI can result in the loss of data being transmitted or stored.
• Equipment malfunction: EMI can cause electronic equipment to malfunction or fail.

Prevention and Mitigation

Several methods can be used to prevent or mitigate the effects of EMI, including:

• Shielding: Using materials that block electromagnetic waves to protect sensitive equipment.
• Filtering: Using filters to remove unwanted frequencies from the signal.
• Grounding: Proper grounding of equipment to prevent the buildup of electromagnetic fields.
• Twisted pair cables: Using twisted pair cables to reduce the effects of EMI on signal transmission.

Standards and Regulations

Various standards and regulations have been established to control EMI and ensure the proper functioning of electronic devices. These include:

• Federal Communications Commission (FCC) regulations in the United States.
• International Electrotechnical Commission (IEC) standards.
• European Union directives on electromagnetic compatibility (EMC).

Related Pages

• Electromagnetic compatibility
• Radio frequency interference
• Electromagnetic shielding
• Signal integrity
• Ground loop (electricity)

See Also

• Electromagnetic spectrum
• Faraday cage
• Noise (electronics)
• Interference (communication)