Electronic Uses of Magnets

Electromagnets are used from products as diverse as microphones and speakers, read/write heads on computer hard drives, and electric motors. It is safe to say that, without magnets, we would not have the plethora of electronic equipment available to us today.

Definition

An electromagnet is a magnet that has electricity applied to it to create changes in the electronic field surrounding the magnet.

Speakers

A speaker has a "cone" that has a magnet at its center. In close proximity to that magnet is an electromagnet that has electrical wires attached to it. When an electronic signal is sent to the electromagnet, it excites the magnet at the center of the cone to create the sound waves that we hear.

Microphones

Microphones work in reverse. Sound vibrates the magnet at the center of the cone. The electromagnet--in close proximity--then sends the electronic signals through the cable to the amplifier or recorder.

Transformers

Step down transformers have large electromagnets that are placed near small electromagnets. The magnetic field of the large magnets affects the field of the small magnets, which sends a direct current through its attached wires at a lowered voltage.

Amplifiers

Within an amplifier, the power is boosted for audio output by step up transformers. Current sent to small electromagnets affects the large ones to step up the power of the current.

Electronic Signals

All electronic signals and electrical currents may be processed at low voltages or even micro-voltages (if in computer chips). Amplifier circuits with transistors boost the power of the electronic signals.