Magnets in Cars: There Are More Than You Think

When we think of magnets, most of us first picture a fridge magnet or a strong neodymium magnet. Yet in a modern car, permanent magnets appear in a surprising number of places – we simply cannot see them. From speakers and electric motors to certain sensors, they play an important role in many systems.

The most familiar example: car speakers

Almost every car has several speakers, while newer models may surround us with an entire sound system. A permanent magnet is one of the fundamental components of a conventional dynamic speaker.

The interaction between the magnetic field created by the magnet and the electric current flowing through the speaker coil moves the diaphragm. Its vibration produces the sound we hear as music, speech or navigation instructions.

So when we switch on the radio, magnets are probably already at work around us.

Small electric motors everywhere

Cars contain many electric motors of different sizes. Think of electric windows, central locking, power-adjustable mirrors and seats, as well as the ventilation fans.

Many of these motors use permanent magnets. The magnetic field and electric current allow electrical energy to be converted into rotary motion.

Behind a simple press of a button – when lowering a window, for example – there is more interesting technology than we might first imagine.

Magnets and sensors

Modern cars are full of electronics and sensors. Some sensing systems also use technology based on magnetic principles.

These systems can detect position, movement or rotation. One advantage is that, in certain applications, sensing can take place without mechanical contact, allowing a long service life and reliable operation.

Drivers usually notice none of this; what matters to them is that the car's systems work correctly.

Then came electric cars…

The spread of electric and hybrid cars has made the importance of magnets even more apparent. Many electric motor designs use high-performance permanent magnets, including rare-earth magnets.

These provide a strong magnetic field in a relatively small space. Combined with a suitable motor design, this can contribute to compact dimensions, high power and good efficiency.

However, it is important to remember that not every electric car has a permanent-magnet motor. Several electric motor technologies exist, and manufacturers choose a solution to suit the requirements of each vehicle.

An invisible technology all around us

What makes permanent magnets remarkable is that we often do not notice them at all. Rather than encountering them as separate components, we find them working inside larger systems.

The next time you turn on the car radio, lower a window, adjust a powered mirror or see an electric car drive past, remember that magnetism is probably working somewhere behind the scenes.

A permanent magnet is much more than something that sticks to a refrigerator. It is a small, often invisible, yet extremely useful part of the modern automotive industry.