Walter A Robbins

US Patent:

51519070, Sep 29, 1992

Filed:

Feb 20, 1990

Appl. No.:

7/482294

Inventors:

Walter A. Robbins - Novato CA

International Classification:

G06F 1100

US Classification:

371 66

Abstract:

An auxiliary direct current electrical power source for protection of a wide variety of DC powered circuits, in particular those of computer systems, upon loss of commercial alternating current (AC) power, to sustain necessary or required functions for the full duration of the ordinary utility company AC power loss. The direct current power source will generally be one or more rechargeable gel cell batteries that are switched directly onto the protected device's internal DC power bus when a loss of AC power is sensed by the present invention. The switch to auxiliary power is inhibited if the protected device was in a manually turned off state at the time of AC loss. At the time of AC power restoral, a time delay ensures that the protected device's own internal power supply will be fully operational before the batteries are switched off the internal DC power bus. If the batteries fall below a predetermined voltage, the auxiliary power supply will switch itself off to avoid unduly low voltage to the protected device or damage to the batteries. During normal AC power conditions, the batteries will be recharged and maintenance charged.