Here's another picture of it powering my 3 watt luxeon LED with one AA. I measured about 3.15V @ 250mA at output. It works best with 2 cells. When I power it up with one, It takes about 5-7 seconds to charge up to full brightness and you can feel the battery get warm.
Here is a prototype that I got working. It's the VPack voltage booster that I ordered from sparkfun electronics in combination with a really simple LM317 setup. First thing I did was modify the voltage booster by replacing the resistor at RF1 with a 200K pot, then I replaced the cap at the...
Here's a little something that could help. It has a minimum input of 1.1V and can be adujusted to be up to 6.5V by replacing RF2 with a pot. I also heard that the output voltage can even be boosted up to 9V by replacing the cap at C2 with one that can handle more voltage. The best part is that...