Definition: power adapter

A power supply for electronic devices. Also called an "AC adapter" or "charger," power adapters plug into a wall outlet and convert AC to a single DC voltage. Computers use multiple DC voltages, and the power adapter is the external part of the power supply for a laptop. The additional DC voltages are created by internal circuits. Desktop computer power supplies are in one internal unit, which converts AC to all DC voltages.

Power adapters also exist for other purposes; for example, to output a different AC voltage, rather than DC. See transformer, power supply, power distribution unit, wall wart, wall tap, power strip and USB charger.

The Laptop Power "Brick"

The weight of a laptop's external AC adapter is hardly ever published in the specs, but it adds bulk and poundage in the briefcase.

The "Wall Wart"

The ubiquitous black adapter with its own AC plug often overlaps the adjacent socket, unless a "wall wart-aware" power strip like this one is used.