Hi,

I'm learning about cuk DC-DC converters, and happen to have a question. Why do you need the two inductors? So far I believe the first one is there to regulate the current when the source is connected to the capacitor through it, but the second one I have no clue.

Thank you

 

You need the two inductors so the converter can both buck (decrease) or boost (increase) the input voltage. The Cuk is basically a boost converter followed by a buck converter.