Patent ID: 6577103
Filing Date: 2003-06-10
Classification: H02J

Abstract:
An emergency power system, comprising a circuit having a DC load, a rectifier and a sodium sulfur battery electrically connected to one another, and a rectifier output voltage controller provided between said rectifier and said sodium sulfur battery,wherein DC power is supplied from said rectifier to said DC load under normal operating conditions and said battery is charged by said rectifier, and electric power is automatically supplied from said battery to said DC load during a power failure or an outage of said rectifier, wherein said output voltage controller lowers an output voltage of said rectifier when a voltage of said sodium sulfur battery reaches a level that is equal to or higher than a predetermined charging voltage, and thus automatically discharges energy from said sodium sulfur battery to said DC load, and said rectifier output voltage controller raises an output voltage of said rectifier when the voltage of said sodium sulfur battery reaches a level that is equal to or lower than a predetermined discharging voltage, and thus charges said sodium sulfur battery.