Study Of Circuit Modeling And Fault Diagnosis

In recent years, a variety of electronic devices have been widely used with thedevelopment of science and technology, and the research of theory and technology onfault diagnosis of circuits for electronic equipments has also made great progress.However, a lot of prior knowledge is required in most popular fault diagnosis methodssuch as Fault Dictionaries, Neural Networks and Expert System. For most importedequipment without schematics and detailed component datasheets, many existingmethods can’t be used in fault diagnosis of this kind of circuits. So this paper, firstly,starts with circuit modeling for the fault diagnosis of unknown circuits. A kind ofcircuit model is established on the basis of input signal, output signal and nodecharacteristics without considering components’ electrical characteristics, connectionand structure. Secondly, a method of analyzing circuit state is discussed in this thesis,rules of searching and locating fault position are studied, which are demonstrated in aform of algorithm. At last, an overall program on circuit diagnosis is summarized,which contains the key technology of all parts, including information extraction, nodeclassification, circuit modeling and fault searching methods. Then every step of thismethod is illustrated via specific simulation examples of two circuits. Experimentalresults demonstrate the method is feasible and effective.