What Devices Use Electromagnets?

By Caryss Woods-Behan
Look around you and chances are you will find at least one item powered by an electromagnet.

Many household items and objects encountered in daily life operate in magnetic fields that occur as the result of electricity moving through metal conductors. Electromagnets differ from the simple, permanent magnets you might see displayed on a refrigerator door; in contrast, electromagnets, also known as temporary magnets, can be switched on or off. Electromagnets can be found in small devices such as doorbells to large machines that pick up and release cargo.



Electromagnetics Defined

Pierre and Marie Curie kept this electromagnet in their laboratory.

An electromagnetic device acquires its power from the magnetic fields that form when electrons travel in an electric current through a metal conductor. Objects powered by electromagnets are considered superconductive, or resistant. They range from small objects that use a single wire for conduction to large, superconducting machines found in medical and institutional settings.

Uses

An electromagnet's strength depends on the current, number of coils and the core.

Ordinary objects powered by electromagnets include telephones, toasters, televisions and door locks. Some automobile parts, including brakes and clutches, use electromagnets to operate. Electromagnets also provide power to electric motors and generators, stereo speakers and circuit breakers.

Resistive Electromagnetic Devices

Researchers often use resistant and superconducting electromagnets to conduct experiments.

Mark Bird, director of Magnet Science and Technology at the Magnet Lab in Tallahassee, Florida, describes resistive electromagnetic devices as magnets that use regular electricity, multiple metal coils and insulators to generate high magnetic fields. According to Dr. Eric Palm, D.C. field director at the Magnetic Lab, scientists all over the world use these high-powered electromagnets as research instruments to conduct their experiments.

Superconducting Electromagnetic Devices

Medical MRI machines use high magnetic fields to produce internal images of the body.

According to Iain Dixon, a research associate at the Magnet Lab, an extremely cold temperature (-425 degrees Fahrenheit) provides an unobstructed passage for electrons as the electrical current moves through conductive material in electromagnets known as superconductors. This type of electromagnetic device includes magnetic resonance imaging (MRI) machines and machines designed for the study of nuclear magnetic resonance (NMR).

Suspended Magnetic Separators

An electromagnetic separator may recover parts of construction equipment in conveyed material.

Dan Norrgran, marketing manager for Heavy Industries at Eriez Heavy Industries Group, explains the function of suspended magnetic separators, which are superconducting electromagnets used in industrial settings. These electromagnetic machines attract and extract metal parts from coal, rock and other materials as they move down conveyor belts.

About the Author

Caryss Woods-Behan uses knowledge gleaned while serving on a parents panel advisory council to the Pennsylvania Department of Health to write about treatment options for chemically-addicted youths. Her experience working as a legal assistant serves as a foundation for writing family-law articles. Woods-Behan studied food marketing at St. Joseph University in Philadelphia, Pennsylvania.