adapter 12v A 12V 2A adapter is a type of power supply that is commonly used to power a variety of electronic devices. It converts AC voltage from a wall outlet into DC voltage that your device can use. The 12V refers to the voltage it outputs, while the 2A refers to the amperage it outputs. It's important to make sure that the adapter you choose is compatible with your device, as too much or too little voltage or amperage can damage your device.