Fascinating tear-down of common USB wall chargers showing why some on the market can be downright dangerous:
Searching for USB Power Supplies that Won?t Explode | HackadayUSB power supplies are super cheap and omnipresent. They are the Tribble of my household. But they’re not all created equal, and some of them may even be dangerous. I had to source USB power supplies for a product, and it wasn’t easy. But the upside is that I got to tear them all apart and check out their designs.