power supply,driver and led?

I have been working on something for a little while now and I figured it would be best to break down and ask the people who know. That would be thanks to my other brother Darell as he directed me to this end of the forum for guidance. Sorry Darell, I couldn't resist, I goof around with one of my friends every time I see him and say Hey it's my other brother Darell. Okay that might be getting old but here's what I'm up to.
I scabbed together this led flashlight from a couple of knock off double cell AAA flashlights. I just pressed the two pieces from two flashlights I cut to the right lengths together in some brass tubing. What do you know, I had a triple cell AAA single lamp led flashlight. I used an 1100 mcd white led lamp running at 20 milliampere from Radio Shack (not the best I would figure now ) and this thing was working fine until the batteries went. I guess it was the next set of batteries that cooked the led because there was one little spark and that was it . Who knew I would need some sort of a driver for this thing anyway, I sure didn't. I WAS real happy with my new toy as the batteries outlasted the knock off flashlights I was working with by about three or four times the duration of illumination with the use of only one more battery. Although it did just keep getting a little dimmer and a little dimmer and .....
To get to the truth of the matter I was an electrical worker for thirteen years but this stuff is pretty far from three phase 208 or 480. If you are talking about phase alignment I just might have a clue if I could find my old books. Go as far as pathagerum theory( I'm not even sure if I spelt it right!) to figure ohms resistance and I'm looking for a Tylenol and cold beer!
The direction I was working on going with this flashlight is a flashlight that will work well in very cold weather, have an extended battery life and fit into this project I have going with another friend of mine. Then I got to looking at the batteries, okay a lithium ion is going to do well into very cold weather but I don't think there is such a thing as AAA type lithium ion battery and if there were I just don't want to pay the price they would cost anyway (I'll be using this flashlight a lot and hopefully so will others). I am left to guess the next best thing concerning cost and value of purchase would be nickle metal hydrate batteries. This would be because they are rechargeable and considering the upfront cost they seem like a pretty good deal over the long haul.
About time I got to the point now isn't it. I am looking for someone that could help me set this flashlight up in a package that would be almost water proof if not. I would also like it to have a diameter of .585 inches or less and length of 6.875 inches tail to tip. Otherwise I may just have to invest in the Tylenol company and Anhieser-Bush to recup some of my loses. HELP!!!
If you would have any interest in helping me retain my sanity and general upstanding manners you can email directly at [email protected]
You could also visit my website to contact me and see the last project I put together so you know how to answer when somebody asks, So what is a laser fishing rod anyway?

"I guess it was the next set of batteries that cooked the led because there was one little spark and that was it "

YOu have to limit the current through the LED.

You can get away with no resistor for some red and green LEDs(I usually test LEDs by connecting them directly to a 2 AAA pack), but the new greens, blues, and whites are more fragile so use a resistor(I usually use 470 ohms for 12v,330 ohms for 9v ,and 150 ohms for 6v).

I have a simple boost converter circuit, described at http://borealis.com/~winnie/LED_BOOST/index.htm

This is the same circuit used in the rainbow light that Craig reviewed at http://www.ledmuseum.org/bike1.htm

This circuit won't work for your application, since it will only function when the output voltage is higher than the input voltage. However this circuit will work if you wish to operate _two_ white LEDs in series from 3 AA batteries. It will also work to run a single LED from _2_ AA batteries.

I've sent the sales pitch by private e-mail

-Jon

Okay I think I might be coming around with this information you guys have supplied. I am pulling at straws here so some feed back would be greatly appreciated.
I think if a guy were to take his voltage from the batteries (three AAA's) to a 60 ohm resistor then to a capacitor rated for the 20 milliamperes and feed the led with that it should work out okay?

Thanks Jonathan,
Since I do not have the space needed for two leds I figure it would be best to contact you and see what you can do with this thing. I am still going to try and get a circuit made up that will work for this thing just to see if I can do it myself. I will have to post it here to see what you folks think of what I have done.

Thank you all,
Wylie

Thanks for the reply, I use a current limiting circuit board for the lasers in my laser fishing rods. I have been told that they were engineered by an ex-NASA engineer but I just buy them as complete modules. My only experience with low volt stuff was book work in school and that was years ago. I do remember something about bad boys rape somebody but violet gives willingly? Looking at circuit boards today with the different looking components and all I am just not sure how to rate them or even really how to calculate any part of the current flow from batteries.
Would you know of any complete circuit boards that would limit the current flow from three AAA batteries for a white 1100 mcd/20 milliamperes led lamp or the parts I would be able to use? I have a soldering iron and feel as though I am pretty good with my hands. As for a VOM I can probably get one loaned to me. My resources are limited but this is something I deal with constantly so with a little help I should be able to pull this thing together.

"Would you know of any complete circuit boards that would limit the current flow from three AAA batteries for a white 1100 mcd/20 milliamperes led lamp or the parts I would be able to use?"

I don't know of any complete boards off hand, but some others here probably do.
The goal is to maintain a constant current through the LED (20mA)as the voltage varies. this isn't easy to do with passive components, so some sort of switching regulator is needed. A linear regulator IC can also be set up as a constant current source.
Hope that helps a bit.

"I think if a guy were to take his voltage from the batteries (three AAA's) to a 60 ohm resistor then to a capacitor rated for the 20 milliamperes and feed the led with that it should work out okay?"

Why do you have the capacitor in there?