New Switching Converter Topology?

[T3sl4co1l]

Does this... exist?  I mean, has it been named, or enumerated anywhere?



Sort of like a Cuk, but swapping the capacitor and switch.  Could be used for low ripple buck (drop D1 and Q2), a kind of extended-winding boost (change D1 to transistor, Q2 to diode, drop Q1 and D2), equalizing source/load (note that switching Q1+Q2 is a I/III quadrant operation), generating a negative rail (set one supply to zero, and move the diodes to a new negative rail), etc.

Tim

[chris_leyson]

Hi Tim, wow never thought of that one before, done a version of a Cuk many years ago based on a back to back pair of Crouse filters US1920948 1933. My argument was that it was all prior knowledge but I don't think it would hold any water legally. Anyway, after a lot of fiddling with transformer coupling I actually managed to get zero ripple or pretty damn close on both primary and secondary at the same time but you could never build it in practice.

[NiHaoMike]

Just seems to be a convoluted tapped inductor buck or boost.

[T3sl4co1l]

Indeed:



The waveform is identical to a tapped buck, with the diode on the CT.  Not surprising, as D1 is inactive, and the positions of the primary and switch can be swapped, giving the traditional form.

Tim

[rmacintosh]

what simulation package are you using?

 

[T3sl4co1l]

Just Altium.  Seems like few use it; it's workable, but leaves much to be desired.

Tim