US Patent 7847435 Intrinsically balanced direct current uninterruptible power supply

An intrinsically phase-balanced direct current (DC) uninterruptible power supply (UPS) is provided. The DC UPS includes first, second, and third alternating current (AC) phase inputs. First, second, and third rectifiers are coupled to the first, second, and third AC phase inputs. A common node is coupled to the first, second, and third rectifiers. At least one DC output is coupled to the common node. The at least one DC output is adapted for connection to at least one electrical load. A battery is coupled to the common node. A blocking diode is coupled between the battery and the common node.