Transformer

electricity · magnetism · engineering

Moves electricity wirelessly. Transformers can send electrical energy between two coils of wire that never actually touch each other. The magic happens through invisible magnetic waves that pass through the transformer's core and create electrical power in the second coil.

Magnetic field does the work. When electricity flows through the first coil, it creates a changing magnetic field. This changing magnetic field then passes through to the second coil and creates electricity there, all thanks to invisible magnetic waves.

Works with changing electricity. Transformers only work when electricity is constantly changing direction, like AC power at your house. With steady electricity going in one direction, transformers don't create that magical magnetic change needed to move energy to the other coil.

No wires needed between coils. Unlike most electrical connections, the two coils inside a transformer don't need to touch or be connected by wires. The magnetic field is like an invisible messenger that carries the electrical energy from one coil to the other.

Discovered long ago. A scientist named Michael Faraday discovered how this works way back in 1831 by figuring out that changing magnetic fields can create electricity. His discovery, called Faraday's law, is the key to understanding why transformers work.