LM317T Voltage Regulator with Pass Transistor

1) Housing I'm going with the SolarForce L2P ($23) www.lighthound.com Special edition of L2 in Mil-spec type III hard anodized natural finish Flashlight host (head assembly + battery tube + tail switch assembly) without built/drop-in Made of aluminum alloy Can use either a LED (Cree/ IR/ UV)-reflector or an incandescent (Xenon) bulb-reflector module Up to 275 lumens of current-regulated output (Cree LED module) Different functions depending on the Cree LED module being used: single or multiple output levels Uses both primary (CR123A) lithium or rechargeable li-ion (16340 or 18650) batteries (not included) Input voltage (LED module): 0.8-4.2V, 4.2-8.4V, 3-18V Input voltage (Xenon bulb module): 3.7V, 6V, 7.4V, 9V, 12V or 14V Tail clicky switch 97 grams (without batteries) Length x diameter (head and battery tube, mm): 140 x 32 x 25 2) Battery: 18650 3000mAh 3.7V Protected Li-ion Battery ($8.99 from HK - month wait for delivery) From what I understand, Lithium Ion bats are very sensitive to under and overcharging. Batteries considered "protected" have built-in circuits that keep them alive and regulated longer. My buddy also mentioned that there is lots of junk out there so try to go with name brands (LG, Panasonic, Sony, Samsung, AW, Redilast). Do not get temped to buy cheaper brands like Ultrafire, Solarforce, Angelfire, etc.. He also mentioned that older (even seemingly dead) Lenovo laptop batteries can be disassembled to retrieve the type-18650 batteries out. Cool. 3 ...



http://www.youtube.com/watch?v=X5QaM2cQaj0&hl=en