Abstract: The UPS has a housing and a casing securely received in the housing to mount a fan assembly that has a fan, two screens mounted on opposite sides of the fan and a mounting board securely engaged with a periphery of the casing to secure the fan assembly to the UPS housing and to isolate the fan assembly from internal components in the UPS.

Abstract: There is disclosed a high efficiency uninterruptible power supply. A voltage boost unit is provided to transform and boost the voltage of an input power for being supplied to a load. A backup power supply unit is connected to the output ends of the voltage boost unit. An average current mode controller detects a current value of the input power when the input power is normally supplied, and detects a current value of the backup power supply unit when the input power is interrupted. A voltage mode controller controls the backup power supply unit to output power based on the current value of the backup power supply unit detected by the average current mode controller. A detection/control unit detects the input and output voltages of the voltage boost unit, so as to determine whether to drive the average current mode controller and the voltage mode controller.