The specs are simple: convert mains voltage to 5 volts ... The sad state of plug-in USB power supplies is one of [DiodeGoneWild]’s pet gripes, and deservedly so. Most USB chargers cram a ...

With mains-powered devices, you don’t have this luxury, and a lack of knowledge, sloppy work practices, or simple mistakes can cost you — and your project — dearly. While you still need to ...