Universal Serial Bus (USB) is a serial bus standard that connects computer systems with external devices. It is also a technical specification for input and output interfaces and is widely used in information communication products such as personal computers and mobile devices. It is also extended to other related fields such as photography equipment, digital televisions (set-top boxes), game consoles, etc. The current USB 3.1 has a transmission speed of 10Gbit/s, a three stage voltage of 5V/12V/20V, and a maximum power supply of 100W.