Abstract: An uninterruptible power supply (UPS) (100) has a housing (111) that supports the major electrical components of the UPS (100), i.e., a transformer circuit (207), a switching circuit (217), and a battery (209). Furthermore, a connector (107;115;117) affixed to the housing (111 ) is capable of removably affixing the UPS (100) to an alternating-current (AC) outlet (102).

Abstract: A voltage regulator controller includes means for determining the tap position based on regulator impedance characteristics. In a preferred embodiment, the tap position determination system is embodied as part of an regulator designed to operate within a fixed percentage range of regulation (e.g. .+-.10%) with the identical number of turns between each of its series winding taps. In this environment, the regulator tap position is determined as a function of the regulator input voltage, the regulator output voltage, the regulator series winding current, system load power factor and internal regulator impedance.