voltage regulator - Building a dual-rail, regulated DC power supply: 1 diode bridge & center-tapped secondaries, or 2 diode bridges and separate secondaries? - Electrical Engineering Stack Exchange
12V 5V Dual Power Supply Circuit Diagram 3A max | ElecCircuit
Dual power supply circuit 3V,5V,6V,9V,12,15V LM317,LM337