Power rail意思

"Power rail" is a term commonly used in electronics, particularly in the context of power supplies and circuit boards. It refers to the conductive path or line that provides a constant DC voltage to various components within a system or circuit. The term "rail" is used because it suggests a track along which something moves, in this case, the electrical current.

In a typical electronic system, there might be multiple power rails, each providing a different voltage level to the components that require it. For example, a system might have a +5V power rail, a +12V power rail, and a -12V power rail, among others, depending on the specific needs of the components.

The power rails are usually connected to the components through vias or connections on the printed circuit board (PCB). They are essential for ensuring that each part of the system receives the correct voltage level, which is crucial for the proper functioning of the electronic devices.

In the context of a computer or other electronic equipment, the power supply unit (PSU) is responsible for generating the various power rails by stepping down the AC mains voltage to the DC voltages required by the components. The PSU distributes these voltages through the power rails to the motherboard, expansion cards, hard drives, and other devices.

It's important to note that the term "rail" can also be used in a more general sense to refer to any power line or bus within a circuit, not just in the context of specific voltage levels.