Analysis/simulation method to determine robustness of inputs and outputs [line replaceable unit]

A method is shown to allow circuit analysis to model Line Replaceable Unit (LRU) inputs and outputs and the connected loads and sources. This model can then determine if LRU inputs or outputs will be damaged under normal operation or during electromagnetic interference (EMI), high intensity radiated fields (HIRF), lightning or power quality tests used to qualify the unit. Thermal and electrical models are constructed from real loads or sources, for the input or output, and the standard qualification tests. The analysis shows whether maximum current and temperature requirements will be exceeded by the parts. This analysis is used to give confidence that the LRU will pass qualification testing the first time. It is shown that transient suppression devices can often be eliminated.