What is an AC adapter?

Alternatively known as an AC/dc adapter, AC DC converter or charger, an ac adapter is an external Power Supply used with devices that run on batteries or have no other power source. AC adapters help reduce the size of a laptop application by alleviating the need for a standard sized power supply. As shown in the image, an AC adapter is made up of a central unit which draws power from an AC outlet.  Then converts the power to DC that's used by the application, and a DC cord that plugs into the computer.

Each AC adapter has a specific power rating, measured in volts or watts that it can handle and output to an electronic device. Because the power rating and type of plug is not universal the AC adapter can only be used with devices with the same requirements and connector size.

If necessary, a Universal Ac Adapter can be used, which is designed to work with many devices, having multiple types and sizes of plugs for connectivity to those devices. The ac dc adaptor may also have a universal input voltage or frequency range, like 100 volts to 240 volts, 50hz or 60hz allowing for a greater range of compatible devices.