10A for 5V Not sure if any of us need that much juice, but if your setup need it, this is the only add-on (POL) that can handle that much.
Not mean to hijack the thread but I already a POL draw up for those who want a little experiment with the soldering iron (after I see you (OP) intended to make a 5A version).
You can build either 5V@5A, 12V@5A, or 5V+12V by using either regulator chip from Maxim or National Semi. The design had proven to work for years (base on my PSU or any old timers who use Mastero/Sproggy PSU.) Very simple to built and doesn't have all the goody from the OP's design. Critical part maybe hard to find.
Price point is a little steep compare to some other POL available from the forum's store like the carnetix or Opus. I know you and I can't get part any cheaper than those big guys to keep the price down. That is why I don't make one to sell but as a leaning experience instead.