5V flashlight

[spencer]

I am thinking about building myself a Mintyboost. For those of you who don't know, a Mintyboost is a USB charger that runs off AA's. Because I would have this portable power supply I thought it would be a good idea to have a flashlight that goes with it. I'm thinking of having it run from any USB port. What is the best way to go about this? I want to use a Cree LED, possiblly with a nice 5A tint. Should I go with a buck converter that is more expensive but probably more efficient or should I go cheap with an inefficient resistor? I would like to drive the LED at about 350mA because I don't want a huge load coming from the Mintyboost. Also, what about heatsinking? I know when run at higher drive levels you need some pretty decent heatsinking. I want to keep it somewhat compact. Would a star board be sufficient?

Thanks,
Spencer

 

[Marduke]

Maybe I'm missing something here, but you are going to use AA cells to power a USB emergency type charger to power a flashlight?

Is there some particular reason you simply cannot use the AA cells in the charger to power the light directly?

 

[spencer]

It is not an emergency power supply. It will be primarly used just for charging my iPod on road trips. I could just use the battery's in the Mintyboost but I want it to be something I can use with any USB port. I guess it's more of a "because I can" project. The Mintyboost is 90% efficient so I don't take a huge hit in power loss by having two circuits.

 

[65535]

Plus you can use it as a keyboard light.