Test strategies for power supplies

Functional and diagnostic testing of switching power supplies offers unique challenges. The control loop and the prevalence of destructive and avalanche failure modes make it difficult to analyze and diagnose many failures. Traditional approaches to resting were applied to power supplies and proved inadequate. This paper illustrates, through examples, some of the problems encountered and their solutions. This paper will also discuss the process through which a depot level power supply tester, the Advanced Power Supply Tester (APST), was defined. The tester features a software environment and Graphical User Interface (GUT) provided by LabWindows CVI and FineSoft, hardware consisting of an assembly of laboratory quality instrumentation, and diagnostic tools