An uninterruptible power supply or UPS is a device that provides power to your equipment even when there is an interruption of the current from your power provider. The heart of the uninterruptible power supply is a battery that stores energy when the power is present and then when power is lost, the battery is used to supply electricity to your equipment.
There are several factors that determine which uninterruptible power supply is appropriate for your application. For a standard home computer a small ups that provides between 5 and 10 minutes of operation is probably sufficient. Most units provide 2 or 3 uninterruptible power sockets and 3 – 5 that simply provide protection and conditioning. This way you can power your computer and monitor during a loss of line voltage for just long enough to save your work and power off the computer. Nearly all uninterruptible power supplies also have a data communication port that allows the computer to detect the outage and begin a shutdown sequence at a specified interval after the event occurs. The UPS also protects you from power spikes and voltage sags as well. A voltage sage (period of lower than operational voltage) can cause a computer to lockup requiring a hard shutdown.
Larger industrial uninterruptible power supplies are designed to handle the heavy loads of servers and can maintain current for up to 90 minutes. These large scale units are most often found in corporate server rooms and large datacenters. If you take a closer look at such manufactures as APC and Tripp Lite, you will find uninterruptible power supply units that provide line conditioning, perfect AC sine wave output, brown out protection to 65 Volts, and $200,000 in plugged in connected equipment insurance. The units can be mounted in a rack and some of the newer models have a true web interface that can be used to monitor status and command the units.
A number of online retailers can fill both your personal and corporate needs. Most manufactures do not sell directly from their websites, but you can usually find a good deal at the major outlets such as Provantage.com, Amazon.com, or Buy.com
