Comment Re:As far as I understood ... (Score 1) 526
The difference is that you would now have two (posibly more effiecient) supplies and inefficient wiring, rather than one possibly inefficient one supply.
An example I have a device that draws ~6W (it is a d-link wireless router). The suplpy that came with it draws 21W from the mains supply. A waste of 15W, a better supply that replaced it draws 7W (85% efficient). Say for instance that I have a household supply to supply 12V from 240V. If it is supplying just this router (and I know I'm simplifiying here) and it is 90% efficient (only likely to be true near the full rated load - but I'll ignore that) then the supply in the device would need to be 93% efficient just to use the same amount of power
(this is completely neglecting wiring losses)
An example I have a device that draws ~6W (it is a d-link wireless router). The suplpy that came with it draws 21W from the mains supply. A waste of 15W, a better supply that replaced it draws 7W (85% efficient). Say for instance that I have a household supply to supply 12V from 240V. If it is supplying just this router (and I know I'm simplifiying here) and it is 90% efficient (only likely to be true near the full rated load - but I'll ignore that) then the supply in the device would need to be 93% efficient just to use the same amount of power
(this is completely neglecting wiring losses)
