This is a simple LED driver/power supply for 5 LEDs. Parts:
It uses the LM7812 positive voltage regulator,
2x 0.1uF Capacitors
RBV - 406 rectifier
5 LEDs (I used transparent green)
A 12V transformer ~500mA
For Typical Forward Voltage use 78 - 100 ohms resistor for Max Forward Voltage use 15-30 ohms resistor
Spark Design PCB: http://designspark.com/page/designspark-pcb-home-page
Step 1: Build It
3) Remove toner
4) Acquire components and solder them as showed in schematic
5) Solder power cord to primary wire windings and connect the transformer
6) Measure for shorts and insulate primary wires, check the polarity of Electrolytic capacitor and LEDs and check the rectifier and 7812
Step 2: Use It
Find a box to put it in if you want and/or add a switch.
Sorry for grammar mistakes or something like that :D.