Uninterruptible Power Supply Systems - UPS

An uninterruptible power supply (UPS) is a module that provides a stable output supply in the presence of a noisy and/or intermittent input supply.  They typically use a battery for temporary storage, but other forms of energy storage such as supercapacitors or flywheels may also be used.  There are three main categories of UPS: standby, direct current (DC) and line-interactive.  A standby UPS just provides surge protection and backup power.  A DC UPS provides even more isolation from the external source by converting it to DC, storing it in a battery or other energy storage device, and then converting it back to alternating current (AC) if necessary.  A line-interactive UPS provides active monitoring and regulation of the input supply and can switch on the fly between the regulated input source and the internal backup source.