You have seen display messages in airports and other transportation terminals. They may look like LEDs but these displays are formed by very small discs. The disc will be black on one side and a different color on the other.

How does it work?

“The disc is attached to an axle which also carries a small permanent magnet. Positioned close to the magnet is a solenoid. By pulsing the solenoid coil with the appropriate electrical polarity, the permanent magnet on the axle will align itself with the magnetic field, also turning the disc. Another style uses a magnet embedded in the disc itself, with separate solenoids arranged at the ends or side to flip it.”


EAM was the supplier for the magnets and solenoid to the largest flip disk wall in the world at the Coca-Cola headquarters in Atlanta, U.S.

Here are some interesting facts about the flip disk wall in Atlanta:

  • The wall is divided into two sections. The left side is 64 ft. by 20 ft., and the slightly smaller right wall is 48 ft. by 20 ft.
  • The display is made from recycled PET, and its 55,860 magnetically controlled, synchronized red-and-white disks display sweeping, artistic images and animations about brand Coca-Cola.
  • Messages and images are designed in house and can be changed continuously or periodically by any networked computer.
  • The display requires minimal energy and maintenance, and is made with durable, long-lasting parts.
  • The wall is the largest installation of its type in the world.


See it in action: