I'm making an adjustable power supply, constant voltage/current and all that jazz, and I'm trying to make everything as small and portable as possible, avoiding bulky heatsinks, and using a switching tracking pre-regulator to reduce the overall volume. I read a lot about noise suppression, and I know there'll still be quite a lot of it, but I concluded that SMPS with short/wide AC tracks and other recommended layout considerations followed by a linear regulator would still be more stable than just a SMPS with additional filter (please correct me if i'm wrong).
Anyway, I have a pretty, center-tapped transformer extracted from some old analogue receiver rated at decent power, and I was wondering whether something like this is possible using two switching regulators. The "top" and "bottom" regulator should be able to have different offsets.
The similar questions I stumbled upon online were mostly about connecting ATX PSUs in series, which are fixed voltage supplies using flyback topology, so yeah, no luck there.
If possible, the topology for the positive output regulator would obviously be the buck converter, but what about the bottom one? Can a buck converter sink the current? If not, is there a right combination of topologies to do what I'd like to without meddling with the transformer?
I mean, I guess I could connect the two identical windings in parallel for max power and use buck + inverting for +/-, right? I would like to avoid that because the transformer would get a lot uglier, and I'm afraid I'd mess it up.
PS: Please do not ask me what do I need the stabile voltage for, it is just for fun, and learning about PSU design along the way :P