What are some examples of external power supply?

Examples of external power supplies include wall adapters, also known as power bricks, that provide power to devices like laptops and smartphones. Another example is a universal power supply, which can be adjusted to deliver various voltage levels for different devices. Additionally, external battery packs or power banks are used to charge mobile devices on the go. Lastly, dedicated power supplies for specific equipment, such as those found in printers or gaming consoles, also fall under this category.