Not to be a jerk, but that sounds like a really good way to kill yourself. Playing with 10+ amps is not a good idea.
Yes PSUs are transformers, but they're also filters and some other stuff.
No offense taken! I don't know much about electricity yet... but it sounds like a pretty simply job.
Well... it's not

. A simple 12V 2A power supply is no problem, even for beginners, but these high amounts of currents require serious designs.