Alternator

Part of speech: noun

Definitions

1. A machine that converts mechanical energy into electrical energy while generating alternating current for power supply systems
2. An electric generator that produces alternating current by transforming mechanical energy, commonly used in vehicles
3. A device that generates alternating electrical current by converting mechanical energy, often found in automotive systems for charging batteries

Etymology: The alternator in your car is named for a current that changes direction, not for the machine's manner of working. "Alternate" comes from Latin "alternare," to do one thing and then another in turn, and from it English took the adjective "alternate," meaning first one way and then the other. The device is built on exactly that principle: its output current reverses direction many times a second, alternating between positive and negative. The ending "-or" is a familiar agent suffix. It passed into English through Old French from Latin "-tor," which named the person or thing that performs an action, as in "actor" or "governor." Attaching it to "alternate" produced a word for something that alternates, and in electrical engineering that became a name for a generator producing alternating current.

Synonyms: generator, converter