Patent ID: 6630750
Filing Date: 2003-10-07
Classification: H02J

Abstract:
A system for supplying uninterrupted DC power to a load to which DC power normally is derived from an AC power source or from an emergency AC power source and a plurality of DC batteries are provided to deliver the DC power to the load when AC power fails to be available, comprising:a load bus; a bank of load rectifiers connected to said load bus, responsive to AC power from said AC power sources to respectively produce DC power for delivery along said load bus to the load; a spare bus; a bank of spare rectifiers connected to said spare bus, responsive to said AC power sources to respectively produce DC power for delivery along said spare bus; a blocking circuit coupling said spare bus to said load bus so as to enable current to flow from a said spare rectifier through said blocking circuit when the magnitude of the DC voltage on the load bus drops a predetermined amount below that on the spare bus; and a controller coupled to sense the voltage on the load bus and from said AC power sources to produce a control signal to enable a spare rectifier upon a failure of a said load rectifier.