US 6,445,986 B1 · Static random access memory backup

Abstract

A data logging system includes a data logging unit, a primary power source, an auxiliary power source and a controller. The controller detects whether the primary power source is available or unavailable and the time at which it became available or unavailable. From the time data the controller will then determine the total time the primary power source was unavailable to power the system. The controller adjusts or increases a predetermined auxiliary power source value by the auxiliary power source usage time period. Upon each occurrence in which the primary power source again becomes unavailable, the controller performs the same operations and further adjust or increases the previously reduced predetermined auxiliary power source value by the next auxiliary power source usage time period. Adjusting or increasing the predetermined auxiliary power source value will continue until a predetermined value is reached which triggers an alert. The alert indicates to an operator that the system requires service.

Claims23

Dependent claims

A vehicle data logging system comprising:

a data logging unit;
a primary power source to power said data logging unit;
an auxiliary power source to power said data logging unit when said primary power source is unavailable;
and
a controller in communication with said data logging unit, said controller operable to determine a cumulative auxiliary power source usage time period by determining a total time during which said primary power source is unavailable.

2 more elements

Dependencies are inferred from the claim text.

Static random access memory backup

Life of this patent

Static random access memory backup

Life of this patent

Abstract

Claims23