An uninterruptible power supply (UPS) is a device that allows a computer to keep running for at least a short time when the primary power source is lost. UPS devices also provide protection from power surges.
A UPS contains a battery that “kicks in” when the device senses a loss of power from the primary source. If an end user is working on the computer when the UPS notifies of the power loss, they have time to save any data they are working on and exit before the secondary power source (the battery) runs out. When all power runs out, any data in your computer’s random access memory (RAM) is erased. When power surges occur, a UPS intercepts the surge so that it does not damage the computer.
UPS in the data center
Every UPS converts incoming AC to DC through a rectifier and converts it back with an inverter. Batteries or flywheels store energy to use in a utility failure. A bypass circuit routes power around the rectifier and inverter, running the IT load on incoming utility or generator power.
