Computer Power Supply -

A is a critical internal hardware component that converts high-voltage alternating current (AC) from a wall outlet into low-voltage direct current (DC) usable by a computer's sensitive electronics. Beyond just providing power, a high-quality PSU acts as a safeguard, regulating voltage to protect components like the CPU and GPU from power surges or fluctuations. Key Specifications to Know How PC Power Supplies Work - Computer | HowStuffWorks

is used when referring to a specific unit already mentioned or the unique one inside a particular machine (e.g., "The computer power supply is found in the corner of the case"). What is a Computer Power Supply? COMPUTER POWER SUPPLY

The proper article for the phrase depends on the context of your sentence. In general English usage: A is a critical internal hardware component that