Electromagnetic Interference

Electromagnetic Interference (EMI) is the phenomenon which occurs when two or more devices interfere due to the external electromagnetic fields. These fields can be from power frequency supplies, industrial machines and other electromechanical equipments. EMI is a phenomenon that takes place when signals from these external fields interact with the electronic devices and may lead to their malfunctioning.

Causes and Impact of Electromagnetic Interference

EMI is usually generated by sources of electromagnetic interference which are usually located in the environment at random. The interference signals can be in the form of low frequency signals and may go up to 1 to 1. 5 MHz. Because these signals are relatively sparse and persistent, they can charge up a considerable amount of energy that may cause equipment damage. The effects of EMI are more severe when the devices that are affected by EMI such as the telecommunication equipment are located close to the source of the interference.

Any device that can be affected by EMI and which is connected to a common power supply will be affected by conducted interference through the power supply. This in turn can cause a chain reaction in other devices that are connected to the same power source and can results in poor performance of the entire system.

High Frequency vs. Low Frequency Interference

EMI can be divided into two categories namely low frequency interference and high frequency interference depending on the frequency of the signals that are involved:

• Low-Frequency Interference: Interference signals at low frequency range which is usually below 1. 5 MHz, have greater energy as they last for a longer period of time, as compared to the first type. This makes them particularly hazardous as they can lead to faults that can stop the entire equipment, not to mention other problems.
• High-Frequency Interference: Interference signals which are at high frequency have less energy density as compared to those at low frequency. Although they do not contribute to the large-scale failures of electronic devices they can still result in failures especially in the sensitive or unprotected circuits.

Managing Electromagnetic Interference

In order to minimize the effects of EMI, it is possible to take the following steps. Some of them are ensuring that devices are properly shielded to prevent interference, ensuring that there is enough space between possible sources of interference and sensitive equipment, and using filters or other electronic components which are designed to either block or reduce interference. Furthermore, it is possible to avoid the conduction of interference through the shared power lines by making sure that the electronic devices are well grounded as well as making sure that power supplies are well isolated.

Conclusion

EMI or Electromagnetic Interference is a major problem when it comes to the use of electrical and electronic gadgets in an environment with other electromagnetic sources. Such coupling of signals induced by EMI affects the working of a device adversely and can even result in failure of the equipment. Although high energy density is typical for low-frequency interference, high-frequency interference may also become an issue for sensitive electronics. It is therefore important to appreciate and control EMI so that electronic systems can work efficiently especially in areas that have many possible sources of electromagnetic interference.