Accession Number : ADD015206

Title :   DC Uninterrupted Power Supply Having Instantaneous Switching Followed by Low Impedance Switching.

Descriptive Note : Patent, Filed 22 Mar 90, patented 15 Oct 91,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Hammond, Russell E ; Northup, Robert L ; Shimp, Alan G

Report Date : 15 Oct 1991

Pagination or Media Count : 9

Abstract : An uninterruptible power supply is provided that incorporates switching circuitry permitting a path for instantaneous DC backup power to be supplied to a voltage-declining primary power supply bus. Once the instantaneous transition is made, battery power is switched to a low impedance path to provide long-term battery power delivery to the bus. At a point where the backup batteries no longer supply useful power to a load, disabling circuitry disconnects the batteries from the load so that excessive draining of the batteries does not result in irreversible battery damage. The uninterruptible power supply of the invention further includes an automatic battery charging circuitry that seeks to maintain the power supply batteries at optimal charge level. To enable an operator to adequately assess battery charge condition, the invention provides battery test circuitry that causes a simulated load to appear at the power supply batteries. Visual representations are then made as to battery status. (Author)

Descriptors :   AUTOMATIC, AUXILIARY, BATTERY CHARGERS, CIRCUITS, DIRECT CURRENT, ELECTRIC CHARGE, ELECTRICAL IMPEDANCE, IMPEDANCE, LEVEL(QUANTITY), OPTIMIZATION, PATHS, POWER, POWER SUPPLIES, SIMULATION, STORAGE BATTERIES, SUPPLIES, SWITCHING, SWITCHING CIRCUITS, TRANSITIONS, VISION

Subject Categories : Electric Power Production and Distribution

Distribution Statement : APPROVED FOR PUBLIC RELEASE