Abstract: There is a provided a system of one or more uninterrupted power supply (UPS) units, each UPS unit having distributed processing system and a network interface for interfacing with a local area network, the network providing a communication between the one or more UPS devices and also to loads powered by such UPS devices. In one embodiment having a plurality of UPSs, one of the UPSs is a main upstream UPS which is in communication with each down stream UPS to which it supplies supplemental power and which in turn supply power to respective loads. In another embodiment the UPS supplies power to a plurality of prioritized loads, and is in communication with each such load over a network and also controls power distribution to each such load through a power distribution module (PDM).

Abstract: A system of one or more UPS units, each UPS unit having distributed processing apparatus and a network interface for interfacing with a local area network, the network providing a communication between the one or more UPS devices and also to loads powered by such UPS devices. In one embodiment having a plurality of UPSs, one of the UPSs is a main upstream UPS which is in communication with each down stream UPS to which it supplies supplemental power and which in turn supply power to respective loads. In another embodiment the UPS supplies power to a plurality of prioritized loads, and is in communication with each such load over a network and also controls power distribution to each such load through a PDM.

Abstract: An UPS apparatus with a back-up battery and successively coupled rectifier, inverter and output filter circuits, having an improved battery charging circuit. The charging circuit has a transformer with its primary winding being part of the output filter, and its secondary winding driving a second rectifier circuit which produces the charging current. The charging circuit contains an impedance preferably connected between the transformer secondary winding and the second rectifier circuit, for capturing only a high frequency portion of the signal from the inverter stage, thereby enabling the utilization of smaller charger circuit elements.

Abstract: Method and apparatus for providing protected power to a computer. A computer monitors the terminal voltage and/or current of a battery supplying power to the computer and uses this information or data to determine when, in the event of failure of the AC utility normally supplying power to the computer, to initiate a pre-programmed automatic shutdown of the computer. The determination is based upon the estimated remaining charge of the battery and the total time required to close all active programs in an orderly fashion; thus allowing the computer to be restarted in a well-defined state.

Abstract: A power supply including a resonant converter is provided with current shunt. The current shunt automatically shunts a portion of current flowing in the resonant converter at light loading of the power supply such that output current flowing in an output circuit connected to the power supply would be reduced toward zero as the operating frequency of the converter moves to a predetermined frequency.

Abstract: An uninterrupted power supply (UPS) system is provided with a power factor correction circuit. The UPS system includes a rectifier having input terminals for connection to an AC utility power source and output terminals. The power factor correction circuit is operatively connected to the input and output terminals of the rectifier to cause the UPS system to exhibit substantially unity power factor to the AC utility power source.

Abstract: An uninterrupted power supply (UPS) systems is provided comprising a rectifier circuit, an inverter circuit and a battery boost circuit. One of the input terminals of the rectifier circuit is for connection to the ungrounded conductor of an AC power source and the other input terminal of the rectifier circuit is for connection to the grounded conductor of the AC power source. The UPS has a pair of load terminals for connection to a load. The input terminal of the rectifier circuit for connection to the grounded conductor is connected to one of the pair of load terminals by an electrical conductor whose electrical continuity is maintained from this input terminal to the one of the pair of load terminals without any isolation device such as a 50 or 60 Hz transformer being disposed between the input terminal and the one of the pair of load terminals.