A discussion to class I test current generators and waveform tolerances

This article discusses 3 types of class I test current generators specified by technical standard IEC61643-11, interpreted their respective circuit principles, voltage and current waveforms and circuit parameter calculation. Comparison is also made in this article with respect to positive and negative characteristics of the 3 circuits, humble proposals toward current tolerances by the standard is presented at the end of the article. The pulse form networks (PFN) of the three generators are Crowbar circuit, over-damp C-L-R discharge circuit and inductor discharge circuit.