Power Supply Unit +
![Power Supply Unit](https://files.ozbargain.com.au/t/28/5828.jpg?h=da5585c3)
A power supply unit ( PSU ) converts mains AC to low-voltage regulated DC power for the internal components of a computer. Modern personal computers universally use a switched-mode power supply. Some power supplies have a manual selector for input voltage, while others automatically adapt to the supply voltage.