This ac to dc power supply can output 5A in continous operation and 12A peak current. This kind of dc power supplies uses a PCB so you can use two case types for IC1, TO-220 or TO-tiga. The regulation of this 12 volt power supply is made with TR1 ( multiturn ). IC1 must be placed on proper heatsink.
LM338 Power Supply Circuit Diagram : 
