Actually these have switching power supplies in them and no line connect transformer to waste power. The amount of power when not connected to the iPad is so small that the electric meter will not even move. If it was using 1 watt of power (it uses less) and left on all the time it would cost about $0.15 a month for the typical electric bill.
Jan - Newport RI
--- In iPad@yahoogroups.com, "doyle.eugene" <doyle.eugene@...> wrote:
>
> A power cube has a transformer as the initial component inside. The input windings are connected to the ac and convert the wall power to a lower level for the charger to use to charge your ipad. This winding creates a load on the wall power that is lost as heat when the charger is not in use. If you have anything creating heat, however minuscule it takes energy. Granted it is very little, but it is wasted energy.
>
