Coil Whine: Stop that Whining!

Let’s talk about coil whine.

Have you ever wondered why some of your electronics make noise, such as a low-level hum or a kind of squeal? If you have misophonia (a severe dislike or hatred of specific sounds) it might be the type of thing that drives you up a wall, even if it doesn’t register at all with your co-workers.

Close up of a power bar and an electric plug.  Coil whine begins in electromagnetic coils inside electronics.
Coil whine begins deep within your electrical components.

What causes coils to whine?

No, you’re not imagining the sound. It’s something called coil whine. The problem happens when the electrical current around the inductor coils in your computer increases beyond a certain point, causing them to vibrate and produce a sound similar to a boiling teapot located in a distant kitchen.

Coil whine happens because of AC power conversion. Components like transformers or inductors use electromagnetism to convert AC mains power to the DC power used by most electronics. If functioning properly, these switched-mode power supplies operate at a frequency well above human perception; however, a poorly designed or defective power supply may create a subharmonic frequency and produce noise as described above.

Other components can cause noise as well. Capacitors are also well known for ‘singing’ under certain conditions.

Is Coil Whine Dangerous?

While all this noise may be annoying, it’s not necessarily dangerous. However, since noise can sometimes be a sign of a defective load, it’s not a bad idea to test equipment that consistently emits any kind of unusual whine. You can also use thermal pads over the inductor coils to lessen the vibration causing the noise.

Please follow all proper safety procedures for your components, and always err on the side of caution when working on any kind of electronics: it’s better to ask for help than to risk injury!

For any kind of equipment repair, please feel free to contact us at 1-800-991-7026, or email us at sales@axcontrol.com.