Electromagnetic interference is a major disruption most people don’t know about in our technology-driven lives. In our explainer, we’ll be defining what electromagnetic interference is, what causes it, and how we can reduce it to keep our electrical devices disruption-free.
Table of Contents
What Is Electromagnetic Interference?
Before we get into the details of reducing it, what exactly is electromagnetic interference (EMI)? EMI is when unwanted electromagnetic waves and signals disrupt the sensitive internal mechanisms of electronic devices.
Without proper protection or prevention, EMI can disrupt any electronic device we use, from cell phones to medical machines. Clearly, reducing EMI is in everyone’s best interest.
What Causes EMI?
There are essentially three main causes of EMI. First, natural EMI can happen from weather patterns that carry electrical, static-like thunderstorms or snowstorms. EMI can also come from outside our world, such as solar radiation or emittances from planets as far away as Jupiter.
There’s also man-made EMI, the predominant form we have to worry about. Manmade EMI comes from our electronic devices, like computers and cell phones, that we use and interact with every day.
Lastly, inherent EMI happens when a device’s electrical systems interact with other internal features. EMI can come from anywhere—even on the same device.
What Methods Reduce EMI?
Now that we know what EMI is and what causes it, how do we reduce it? There are three main methods for reducing electromagnetic interference: filtering, shielding, and grounding.
Filtering
Filtering reduces EMI by filtering out unwanted signals. Typically, an AC line is used to block signals from entering the powered circuits. It’s common to see a filter that blocks out any noise outside of a certain frequency range to keep out disruptive noise.
Shielding
The preferred way to reduce EMI is with shielding because it’s typically the most effective and can be on all kinds of devices, big and small. EMI shielding is when the circuits inside a device are encased in a sealed enclosure, like a metallic box.
The vacuum sealing reflects unwanted signals and absorbs any that aren’t reflected.
Grounding
Lastly, we have the grounding method. As you can likely guess, grounding is when a conductive path is established between an electronic device and a point on the ground. Many people use multiple grounding points for the best results.
Now you know the main methods for reducing electromagnetic interference. Even if you don’t know it, EMI reduction is vital to the use of the electronic devices we use every day.
