UPS is known as an uninterrupted power supply. It is also known as a battery back-up, provides emergency power and, depending on the topology, line regulation as well to connected equipment by supplying power from a separate source when utility power is not available. The primary advantage to a UPS is that in cases of sudden power loss, such as during a storm, the UPS will continue to power the computer system long enough for us to save our work. A UPS, however, can be used to provide uninterrupted power to equipment, typically for 5–15 minutes until an auxiliary power supply can be turned on or utility power is restored.
A UPS is typically used to protect computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. There are various common power problems that UPS units are used to correct. Voltage sag will be Transient under-voltage and its Causes flickering of lights. UPS systems can be designed to be placed inside a computer chassis. There are two types of Internal UPS. The first type is a miniaturized regular UPS that is made small enough to fit into a 5.25? CD-ROM slot bay of a regular computer chassis. The other type are re-engineered switching power supplies that utilize dual power sources of AC and/or DC as power inputs and have an AC/DC built-in switching management control units. The only disadvantage is that batteries have a certain lifetime (3-5 years) and therefore there is an expense involved for it.
