Soft Fault Diagnosis in Analog Circuit Based on Fuzzy and Direction Vector

A circuit basic theory of fault diagnosis for analog circuit with parameter tolerance is proposed in this paper. The approach uses direction vector of voltage increment in test nodes as fault signature for predefined faults. A linear equation is built to locate faulty element. On the condition that the component tolerances are taken into account, the concept of direction vector and fuzzy analysis method are combined together to analyze parametric fault. Examples illustrate the proposed approach and show its effectiveness.