Here's a schematic of the driver:



And a picture of the final product:



Parts List:
Cb: 0.01uF
Cbyp: 0.1uF
Cin: 4.7uF, 25V
D1: ?? Schotky something or other
L1: 100uH, 5A
Ron: 210kOhm
Rsns: 0.22Ohm


I was able to build this "viturally" for free, but then i have excellent sources for surplus electronic parts and knick knacks. I wouldn't recommend building a driver, there are excellent off the shelf solutions out there for pretty cheap.