Not so long ago someone warned that it was a bad idea to get your SD cards from ebay. However at least with SD cards the worse that is likely to happen is a corrupt OS install. I'm posting this to inform you that SD cards are not the only thing you shouldn't be buying on ebay.
The following post recently came up on a mailing list I subscribe to titled ""
The USB PSUs in question apparently had no regulation at all and if run on a 240V supply could output nearly 10V.
What will happen to a pi if something puts nearly 10V on the 5V line? My guess is it's very likely to fry some components (what exactly is powered off the 5V line directly anyway?).
That was me who posted the SD Card warning.
Anyway, brilliant post, this! Do you mind if I add it to my signature along with the SD Card warning?
Just add LM7805 before power input of r-pi. For use in car or home its wise to add some voltage stabilizer, just bo be on the safe side. Then you can use a cheap ebay supply.
I'm not sure why anyone would want to risk using one of these or one of these, myself. Never mind the risk to the Raspberry Pi - what about the risk to life and limb? (The BBC covered a particularly tragic story relating to exactly that in the programme "Fake Britain" in 2010, on that note.)