This study deals with a single soft fault diagnosis of non-linear circuits having multiple DC solutions. The key problem of the diagnosis is arranging a measurement test. Creation of the test for the above-defined class of circuits is discussed in detail. It is assumed that only input and output terminals are accessible in the circuit. The test is created based on some single-valued input or transfer characteristics traced in a modified circuit. The modification does not disturb the integrity of the circuit and is realised by connecting some components to the accessible terminals. A very fast method for tracing the characteristics is developed. Having appropriate characteristics several values of the exciting voltage are chosen and the corresponding values of voltage or current defined by the characteristic are measured in the course of testing. The method for arranging the measurement test is illustrated using four non-linear circuits having multiple DC solutions and three of them were built in bipolar and complementary metal-oxide-semiconductor (CMOS) technology. One of the circuits is comprehensibly diagnosed using a method for detecting, locating, and estimating values of different faulty parameters exploiting the proposed test.

中文翻译：

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具有多个直流解决方案的非线性电路的软故障诊断

这项研究涉及具有多个直流解决方案的非线性电路的单次软故障诊断。诊断的关键问题是安排测量测试。详细讨论了针对上述电路类别的测试的创建。假定电路中仅可访问输入和输出端子。该测试是基于在修改后的电路中跟踪的某些单值输入或传输特性创建的。修改不会干扰电路的完整性，而是通过将某些组件连接到可访问的端子来实现的。开发了一种非常快速的特征跟踪方法。具有合适的特性，可以选择几个励磁电压值，并在测试过程中测量由特性定义的相应电压或电流值。使用四个具有多个DC解决方案的非线性电路说明了布置测量测试的方法，其中三个采用双极性和互补金属氧化物半导体（CMOS）技术构建。使用用于检测，定位和估计利用所提出的测试的不同故障参数的值的方法来全面诊断其中一个电路。