UPS

UPS or Uninteruptable Power Supplies are generaly used to provide a level of protection from power outtages.
The most commonly known UPSs are used on desktop computers and servers, but forms if UPSs are used in a wide range of services including cellular stations, traffic lights, radio repeaters, video survelence systems, and may be used in many situations requiring a stable source of power.

Small UPS systems generaly consist of an invertor, battery, or battery banks. Larger systems may include generators that can be powered by gas or diesel engines, wind , and many other sources.
Many UPS units contain surge suppressors , and line conditioners for added protection for connected equipment. The most common invertor design found in a UPS are modified sine wave, more expensive units use a pure sine wave.