I'm looking to build a 3 rail regulated supply (+5v, +-12v) and I've got a bunch of cheap but functional buck converts from aliexpress. I'm wondering if I can run these off a single AC-DC converter (wall wart, etc) and get a common-ground 3 rail supply from this?
I'm thinking something like:
Will that work? Or do I need to introduce a multi-tap transformer or similar solution? The buck converters are these.