I'm having my house (in the UK) rewired and want to install some PIR sensors (link) in a few rooms. Instead of using batteries there's an option to have them permanently powered via USB cable. Is there a device (transformer?) I can have my electrician install to step the mains power down and provide a permanent USB supply?
EDIT: Maybe something like this is what I'm after? A 240V to 5V Switching Power Converter. Unfortunately there's not much info on it...
EDIT2: Thanks for the help I've found what I was after: USB Euro Module Charger