I'm writing a book about repairing electronics. The audience level for the book is "very little knowledge about electronics" and it's mostly about the mindset and mindtools for finding problem sources and how to correct them. It's not buried in maths or anything like that, as it's not a electronics book per se.
That being said, I'm currently a bit stuck on the current chapter about power supplies. I've been describing the very basics of linear supplies (fuse, graetz-bridge, filter cap, regulator, output cap), where error sources most commonly appears, et cetera. I think I've managed to capture the spirit of the linear supplies, but I have a very hard time describe SMPS on a very basic level and this is what I'm asking for input of.
I could slam the reader with block diagrams, schematics and describe the basics of this very complex topic, but I'm afraid I will miss the audience the way I've been trying to pinpoint it all. There's an awful lot of maths and electrical engineering behind SMPS but I want to avoid all that and just show-and-tell the very spirit. Showing a schematic like the one below (not mine) will only boggle the reader, I think, but somehow I have to highlight at least one schematic and point at which components fail most, etc.
How can I express myself about this topic, on a basic level?