An uninterruptible power source (UPS) for supplying power to a barrier operator when mains power has failed is disclosed. The UPS includes a UPS controller for detecting and responding to a mains power failure and capable of generating a plurality of control signals. A backup power source and an up-converter is connected to the UPS controller, wherein the up-converter increases the voltage of the backup power source when needed. A switch is responsive to one of the plurality of control signals of the UPS controller and toggles the operator barrier between the up-converter and the mains power source, and awakens the operator via a standby receiver power line. Another embodiment awakens the operator anytime a UPS receiver receives a preamble of a wireless transmission signal. Auxiliary lighting may also be associated with the UPS and/or photo-electric safety devices.