A unified AC fault diagnosis method for analog circuits based on iterative simulation before test

Based on the fault feature locus with the change of the component parameters in node-voltage space, a fault diagnosis method based on AC iterative simulation before test is proposed. The slope fault model under AC sinusoidal excitation is analyzed first, the idea of the AC iterative simulation before test and the fault diagnosis after test according to the parameter scanning simulation result is proposed; secondly, the procedure of the AC iterative simulation before test and fault diagnosis algorithm after test are both described. Furthermore, the test system of hardware and software for practical experiment is designed, mainly realized the signal acquisition and data analysis. The experiments of simulation and the practical circuit-board are implemented to validate the efficiency of the proposed method.