The AC adapter, AC/DC adapter or AC/DC converter is a type of external power supply, often enclosed in what looks like an over-sized AC plug. Other names include plug pack, plug-in adapter, adapter block, domestic mains adapter, line power adapter, or power adapter. Informal terms include wall wart, wall cube and power brick. AC adapters are used with electrical devices that require power but do not contain internal components to derive the required voltage and power from mains power. The internal circuitry of an external power supply is very similar to the design that would be used for a built-in or internal supply.

Classmate & Rugged:

AC ADAPTER 20V+3PIN POWER CORD FOR NB5010

http://en.wikipedia.org/wiki/AC_adaptor