I need to build a "mini" power supply for a project that i'm making.
The power supply have to output an average of: 12Vdc 500mA
I've already saw some schematics on the web but none of them is "mini" enough.
I need to (at least try) insert a power supply inside a 1 cm height per 20 cm width box.
Do you think it's possible? Even if i have to make my own transformer or something?
Yes it is possible. You may use Viper12 or Viper22 and EFD15 series ferit transformer. On web site of ST you may find also design program and some application notes.