Patent ID: 8738184

Claim:
A fault detection system for an electrical current provision device, comprising: two sensors for sensing two operating characteristics of the electrical current provision device to generate two confidence estimates of whether a problem is occurring, a decision circuit for combining the two confidence estimates to generate a combined confidence estimate, and for taking a predetermined action when the combined confidence estimate exceeds a predetermined threshold; a third sensor for sensing a third operating characteristic of the electrical current provision device to generate a third confidence estimate of whether a problem is occurring, wherein the decision circuit is also for combining the third confidence estimate with the two confidence estimates to generate the combined confidence estimate; and a fourth sensor for sensing a fourth operating characteristic of the electrical current provision device to generate a fourth confidence estimate of whether a problem is occurring, wherein the decision circuit is also for combining the fourth confidence estimate with the two confidence estimates and the third confidence estimate to generate the confidence estimate; wherein the three confidence estimates of the operating characteristics are η 1 , η 2 and η 3 , and the combined confidence estimate is [1 −(1 −η 1 ) * (1 −η 2 ) * (1 −η 3 )].