LED newbert needs your help

[drbone]

Hi, I'm new here. I work for a digital arts program at the university of washington, and one of our composers has given me the task of figuring out how to track the location of a trombone slide as it is being played. The prototype we've been using for a few weeks uses an led that moves with the slide, and a fixed photoresistor whose resistance varies with the intensity of the light as it moves with the slide. This works surprisingly well: so much so that I now need to make it a lot more robust and tweakable. I knew absolutely nothing about leds when I put the prototype together, so I powered the led directly with a AAA battery. This works for awhile, but we go thru leds pretty fast. I need to figure out how to power the led, and control the intensity of the light in a better way. It occurred to me that I am more or less making a funny sort of flashlight, and so here I am asking you guys for help.

I have been using 3-6k mcd leds from rat shack. This is about the amount of brightness I need, although I do need some way of adjusting the amount of light the led produces. I have seen the drop-in flashlight modules sold by Yamaguchi Consulting (who moderates here I think), and I have seen the Mini Dimmer from theledlight.com. Do you think some combination of these products would get me towards where I need to be?

The light needs to be small (it will be affixed to the end of a 1/2" diameter tube), light-weight, should run for an hour or two on a AAA or lithium battery. I appreciate any and all help any of you have to offer. Who knows, maybe I'll start modding flashlights after this project is finished up...

Thanks.
Chad

 

[logicnerd411]

Well, Arc Flashlight makes an Arc AAA that runs on (surprise) an AAA battery. Lasts 5 hours with full brightness, but it costs around $20. I don't think the modules from dat2zip will help you as they are for Luxeon Stars - way too bright for your application (unless you want to blind the player).

Dan

 

[AilSnail]

I don't understand how you can burn out leds with one AAA without reversing polarity. Don't they all require more than 2volts to operate within spec?

 

[BentHeadTX]

Dorcy AAA?
Those Dorcy AAA flashlights might work for you, they cost about $6 at Wal-Mart and have the LED and curcuit board you can quite easily remove. Less us know what you decide and good luck with your project.