Things that you will need to make this power supply is...

• Piece of PCB board

• Four 1N4001 diodes

• LM7812 regulator

• Transformer 12V output and 2A current

•  4700uF capacitor

• 1uF capacitor

• Two 100nF capacitors

• Jumper wires (I used some plain wire as jumper wires)

Also you will need the tools to make this power supply...

• Soldering iron

• Wire cutters

• Wire strippers

• A thing you can cut veroboard tracks.

• Hot glue (To hold components down and make the power supply physically strong and sturdy.)

• And some other tools that you might find helpful.

 

 

Well, read the schematic and build the power supply!

Make sure you get good solder joints and no solder bridges, otherwise your power supply won't work!

After you had built your power supply, test it with your multimeter to make sure they are no solder bridges. 

After you tested it, put it in a plastic box or something to protect you from shocks. 
But do not operate the power supply like I did, it is very dangerous because of the mains voltage on the transformer, you or somebody will get badly shocked! 

My power supply has 11.73v output, not too bad, I don't need it to be exactly 12v...

 

You had built a cheap power supply! You can use it for what ever your needs... 
But again do not operate it without any protection! 
 

Check this out for further explanation..