is it possible to power external hard drives using 12v 20/60W Lighting Transformers

[2005guyver01]

Hi

I have over 20 External Hard Drives.
I would like to keep things nice and tidy by creating a box that has the mains going in and 20 drive cables coming out, each having it's own SW.
I was wandering if anyone knew if it was possible to use a couple of 12v 20/60W lighting transformers?, instead of pulling all the individual PSU's apart copying there circuits and having a transformer for each drive. The objective is to keep it tidy and small.

[Goobley]

AFAIK these transformers are all AC, but the drives obviously all need DC, so if you're handy with a soldering iron then I'm sure that you could knock up a full wave rectifier followed by a few caps and a DC-DC Buck converter. However the important question here is whether you need to run all the drives at once. Working from the spec for a Caviar Green, while reading or writing it requires 1.78A@12V, assuming some of the drives are not as efficient as a Caviar Green (so assume 2A per drive) to have them all running at once would require at least 40A. Unless you're really quite knowledgeable in power supply design you probably do not want to be playing with that sort of current.

So if you want to run them all at once you're looking for a 500W+ power supply, looking at farnell that's not gonna be cheap (see link below), although clearly you could get a computer PSU for a lot less than this that'd be capable of powering all these drives. You'd have to trick it into turning on (shorting green to ground in 24pin) and then could solder some barrel conecters to go to your drives from the various 12v and GNDS available on the PSU.

If however you don't need to have all of them spinning at once, if you need say 3 drives at a time then you can get away with something like a 60W PS, (something a long these lines http://uk.farnell.com/tracopower/txl...60w/dp/1205093) you'd still have to sort out wiring to each drive, but with something like this you could at least tuck them all away in a box


Big Link showing the cost of 600W enclosed supplies:
http://uk.farnell.com/jsp/search/bro...alues%3D213135