This article looks at some of the reasons why the filters you may think will work often do not when they’re put into real circuits. So… let’s talk about why filters fail.
In this article, the author will identify two major types of single-conductor structure resonances and describe some case studies for both. He will then describe how design projects can quickly and easily be ‘de-risked’ from the possibilities of suffering either type of resonance by the use of low-cost field and circuit simulators and/or low-cost bench testing on physical ‘mock-ups’.
In this article, square unshielded wire loops are compared to shielded solutions including simple techniques to build them in your lab. Some examples are included to show that unshielded loops often work as well as shielded loops in some applications, especially for injecting signals into circuits.
There have been inherent problems with audio frequency conducted susceptibility tests since their inception. These are: ensuring that the injected signal drops across the test sample; monitoring the signal that is developed across the test sample, both from the point-of-view of isolating the instrumentation so it doesn’t ground the input power return and, more problematically, monitoring injected ripple riding on an ac bus potential. These issues are resolved using a novel but inexpensive transducer described herein.