0 12V DC supply using 7812 IC

One of the simplest 12V power supply unit that can deliver a maximum current of  1.5A. Good power supply for charger, electronic circuits, and other devices.

12V regulator

7812 pins

Part List:
7812 - LM7812 or any 12V regulator IC
C1 - 470uF electrolytic capacitor rated 25V (can be removed)
C2 - 100uF electrolytic capacitor rated 16V (can be removed)
DC in - see AC-DC converter circuit below

AC-DC converter

Part List:
Transformer - 220V-15V or 110V-15V center tap minimum rating 15VA
D - any 2A rated diode
C - 1000uF (higher the better)  electrolytic capacitor rated 25V

You can add fuse in series with AC main or output for protection. If you find that its current capacity is too low for what you need, you can try building the high current 12V power supply circuit.