C: KL- 3815 $129
Unregulated Power Supply, 500 W, 38VDC/15A, 120VAC or 230VAC
This unit includes 500VA toroidal transformer, 2 of 10000uF 40V capacitors,
25A 600V bridge rectify, and chassis
Note: The transformer is CE certified

Que te parece esta opcion? Asi me ahorraria el trabajo de armarla. Es de http://www.kelinginc.net/SwitchingPowerSupply.html