[Yannick] got a hold of a 100W LED diode recently, and like any self-respecting hacker, he just had to turn it into a ridiculously over powered flash light. The tricky thing about these diodes is t… ...

You can get 12v, 8v, 100v, or whatever between capacitor leads, depending on the internal resistance of the fan. It’s just a 2 resistor divider. The bulb and the fan resistances.

D3 – 12V 400mW Zener Diode Q1, Q2, Q4 – BC547 NPN Transistor ... % duty cycle drives the input of TIP41C transistor.1000uF capacitor smoothens the output voltage of the dc-dc converter.LED and 1.5Kohm ...