I'd like to build a bike light project. I plan to have two lights, one cree XML or similar powerful emitter at the front (1-200 lumens ish) adn a Seoul P4 for the rear (native red, 80 lumens). They both need slightly more than the 40mA an Arduino pin can provide (more like 3-700 mA!). I see a lot of these sorts of lights (and torches) use Li Ion batteries. I'd like to keep it simple and use AA/AAA rechargables.
Now for the questions!
(1) what's the maximum mA I can expect to be able to draw from AA/AAA x3 (in series for 3.6v)
(2) is 3.3v logic safe at 3.6v in gneral? Or am I pushing my luck?
(3) is there a simple, yet very efficient driver circuit for the emitters (I understand they need have the current controlled accurately). Note that I'd like to retain the ability to flash or PWM control the brightness
Thanks,
Philip