Quote:
Originally Posted by Piwoslaw
All electronics are really DC powered, even though they are fed AC from the grid, which means that each TV, DVD, SAT, stereo, computer, etc., has a transformer+rectifier inside. How efficient is that? Would it be more efficient to have one larger transformer supplying power to the LCD/DVD/SAT/home theater bundle in the living room (hacking those devices to directly input DC)?
From Wikipedia - Tranformer, Energy losses:
I've looked around for info on the efficiency of the AC-to-DC conversion in typical electronics devices, but no luck. Only some random talk of full-load and no-load efficiencies, windings, cores, eddies, hysteresis, etc. Most efficiency/load charts seem to be for industrial sized, multi-kVA transformers. From tid-bits of information I've pieced together it appears that some transformers' efficiency increases with load, while for others the maximum is in the 30%-60% load range, after which it decreases.
So the question remains: Several small transformers, or one larger one? |
Most electronics nowadays use switching power supplies instead of transformers. They're far more efficient, and can handle a wide range of AC (and sometimes DC) voltages.
Combining power supplies makes sense in a single area where multiple devices reside (as in NiHaoMike's example), but higher voltage moves with less loss over the same wires, so it's more lossy to run, say, 12V all over the house than it is to have individual power supplies tapping off 120V or 240V.