Uninterrupted Power Supply (UPS) Krish Advani 01/03/2013 Engineering UPS is a device connected between the primary power source and a computer to provide uninterrupted electrical source. UPS also known as Uninterrupted power source or a battery backup is a device which maintains a continous supply of electric power to connected equipment by supplying power from a separate source when primary power is not available. An alternative power source, usually a set of batteries, used to power a computer system if the natural power service is interrupted or falls below acceptable levels. A UPS can often supply power for just long enough to let you shutdown the computer in an orderly fashion. It is not designed to support long-term operations. Sometimes lighting, storms will kill or destroy the power for just a second, which is enough to erase the data in computer´s temporary memory. Thus the total of power can be avoided with battery – based power systems. Such systems are called Uninterrupted Power Supply(UPS). A UPS generally protects a computer against four power problems: Voltage surges and spikes. Voltage sags. Total power failure. Frequency differences.