POWER SUPPLY

This article is about the common off-line switching power supplies used in desktop IBM PC compatible computers. There are many other kinds of computers with differing power supplies.

A computer power supply unit (Computer PSU), or Modular Power Supply Unit (MPS) is the component that supplies power to a computer. More specifically, a power supply is typically designed to convert 100-120 V (North America and Japan) or 220-240 V (Europe, Asia and Australia) AC power from the mains to usable low-voltage DC power for the internal components of the computer. Some power supplies have a switch to change between 230V and 115V. Other models have automatic sensors that switch input voltage automatically, or are able to accept any voltage between those limits.

The most common computer power supplies are built to conform with the ATX form factor. The most recent specification of the ATX standard is version 2.2, released in 2004. This enables different power supplies to be interchangeable with different components inside the computer. ATX power supplies also are designed to turn on and off using a signal from the motherboard (PS-ON wire), and provide support for modern functions such as the standby mode available in many computers.

Contents [hide] 1 Wattage 2 Appearance 2.1 External 2.2 Connectors 2.3 Internal 3 AT vs. ATX 4 Laptops 5 Energy efficiency 6 Small facts to consider 7 Wiring diagrams 8 False Advertising 9 Modular power supply 10 Troubleshooting 10.1 Capacitors 10.2 Noisy fan 11 See also 12 External links 12.1 Computer Power Supply Calculators

[edit] Wattage