Step 1: Things that you will need...
Things that you will need to make this power supply is...
Piece of veroboard
Four 1N4001 diodes
LM7812 regulator
Transformer that has an output of 14v - 35v AC with an output current between 100mA to 1A,
depending how much power you will need. (I found a 16v 200mA transformer in a broken alarm
clock.)
1000uF - 4700uF capacitor
1uF capacitor
Two 100nF capacitors
Jumper wires (I used some plain wire as jumper wires)
Heatsink (optional)
You should be able you get most (maybe all) of the parts at Radio Shack or Maplin.
Step 2: And the tools...
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.
Step 3: Schematic and others...
If you want a 5 volt power supply, just simply replace the LM7812 to a LM7805 regulator.
Datasheet for LM78XX
If you are going to pull out about 1 amp from this power supply, you will need a heatsink for the
regulator, otherwise it will generate very high temperatures and possibly burn out...
However, if you are just going to pull out a few hundred milliamps (lower than 500mA) from it,
you won't need a heatsink for the regulator, but it may get a little bit warm.
Also, heres the schematic...
I also add in an LED to make sure the power supply is working. You can add in an LED if you
want.
Step 4: Make it!
Well, read the schematic and build the power supply!
If you don't know how to read schematics, you might want to look here.
Make sure you get good solder joints and no solder bridges, otherwise your power supply won't
work!
Oh, If you don't know how to solder, read this great instructable! How to solder!
Step 5: Test it!
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...
Step 6: Done...
