We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is a Voice Coil Actuator?

By Paul Scott
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A voice coil actuator is an electromagnetic device that supplies a controlling motion for secondary mechanisms. Similar in operating principle to conventional solenoids, it differs in that the coil of the actuator moves within a static magnet array. A voice coil actuator is also capable of producing bi-directional movement. In addition, its range of output motion may be controlled by external triggers and system feedback. Also known as voice coil motors, they may be configured to produce linear and rotary outputs.

The phenomenon of electromagnetic force is the cornerstone for a wide range of switching, actuation, and control mechanisms in an equally extensive range of industries. The most common application of this phenomenon is the simple solenoid. These ubiquitous devices consist of a static wire coil and a moving plunger used as a output transfer agent. When the coil is energized with an electric current, a strong magnetic field is generated which causes the plunger to move towards it. This movement is then harnessed to perform work.

The voice coil actuator also relies on this electromagnetic force to supply its output motion, but does so in a different fashion. These actuators feature a static magnet array and a moving coil that is used to transfer motion. When an electric current is passed through the coil, a magnetic field is generated around it in the same way as a conventional solenoid. This field interacts with the static magnet's field, either attracting or repelling the coil depending on the phase relationship of the two fields. This working theory can be easily demonstrated with two small bar magnets that either push each other away or pull towards each other depending on which way they face.

In this way, the voice coil actuator, or voice coil motor, as they are also known, may be used to produce a range of finely-controlled, bi-directional linear motion. The actuator may also be configured to produce a finite rotary motion, typically less than 360 degrees. The voice coil actuator may also be configured as part of a servo system where installation feedback or inputs are used to dictate its motion range. A very common application for voice coil actuators is the read and write head on a computer hard drive.

One of the most well-known uses of a voice coil actuator, however, is the audio loudspeaker. The cone of the speaker is attached to a voice coil and is moved backward and forwards by the alternating polarity of an audio signal passed through the coil. This, in turn, creates the air pressure waves that produce the speaker sound output.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources
Discussion Comments
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.