A power supply is an electronic device that supplies electric power to another device, such as a computer, monitor or printer. This is achieved by converting wall power (or mains power) to a lower voltage, and in most cases also from AC to DC. Most power supplies also provide protection from overload, power surges and other potentially problematic or hazardous conditions.
Power supplies for desktop computers are a standard design, but vary in output power. If you have more powered components (hard drives, optical drives, graphics cards, etc.) in your machine, you'll need a larger power supply. This is the main consideration when upgrading your computer.
Power supplies for laptop computers are usually specific to that make of laptop with each one potentially having a different output rating and connector. If you need to replace your power supply, you need to make sure you get one that's compatible:
- Can I safely charge my laptop with a non-standard, third-party charger?
- Will my new laptop AC power adapter work with my laptop, given these specs?
- ups (uninterruptible power supply)