An uninterruptible power supply (UPS) is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide near-instantaneous protection from input power interruptions, by supplying energy stored in batteries. The on-battery run-time of most UPS is relatively short (only a few minutes) but sufficient to start a standby power source or properly shut down the protected equipment. It is a type of continual power system.

A UPS is typically used to protect hardware such as computers, data center equipment, electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. UPS units range in size from ones designed to protect a single computer (around 300 VA) to large units powering entire data centers or Factory buildings.There are mainly three type of UPS categories.

Line Interactive UPS:

This Type of UPS Take some small time (Typically 5ms) to    changeover from mains to backup source. This type of UPS are used for single PC, or for house         Backup.

Online UPS:

This Type of UPS Take no time to changeover from mains to backup source. This type of UPS are used for datacenter and big industries.


This Type of UPS provide DC Output. This type of UPS are used for small gadgets, CCTV, Cordless phone, EPABX or special equipment.