Possible Duplicate:
Do USB sockets draw power when not in use?

We're about to re-wire our house (in the UK). It occurred to me that having the ability to plug USB devices directly into wall sockets to charge would be very convenient (as opposed to use their own chargers, which both uses up a socket in a room, and we inevitably fall into the bad habits of leaving the charger plugged in, thus drawing load even when it's not charging).

Is this a common thing? Is it possible? What kind of issues are there?

We're in the UK, so are particularly interested in answers within that context.

  • 1
    You would need either a low voltage DC supply or a transformer in the wall - both of which would be "on" when devices aren't plugged in. You would be better off looking for chargers that turn themselves off when there's no current being drawn.
    – ChrisF
    Aug 19 '12 at 21:56
  • Before you go to the trouble, why not measure the actual load your USB chargers draw, and see if it's enough to worry about?
    – Jay Bazuzi
    Aug 20 '12 at 1:44
  • Is it possible, yes, products exist for this. The rest of the question, is it better or more energy efficient, appears to be answered in a duplicate question.
    – BMitch
    Aug 20 '12 at 3:21
  • Thanks, that and the dupe have told me what I wanted to know. Aug 20 '12 at 22:32

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