DC powered LED circuit for Burning Man Art

Discussion in 'The Projects Forum' started by Dolomite, Mar 21, 2009.

  1. Dolomite

    Thread Starter New Member

    Mar 21, 2009
    Hi there,

    I'm working on an art project to take out to the desert for this year's burning man. My avatar is a photo of what the end result looks like when its working. Basically, I've taken a hard hat (like for construction), and put in a bunch of fiberoptic bundles i got from tablesettings. That year, I used the battery cases and LED's the table settings had, but that had a number of problems (big weight from so many batteries, too many haphazard wiring, etc). (pic in my avatar is of last year's effort). So I've gutted the insides and would like to set up a single LED string to light up the fiberoptics.

    I had gotten some advice, and purchased some rotating color LEDs - the help told me that they had resistors built into them, which made them easier to use. Here's the detail I have (and a link to the site i purchased them from):

    My helper suggested that I hook "20 or so" of these up in parallell to a 4 AA battery pack. When I had all the parts, I started testing some of the LEDs with the battery pack, and after some stopped working, I figured out something was wrong. I suspect its voltage - the 4 AAs in series equal 6 volts, but the information says the LEDs want 3.8 - 4.2 V.

    So my question:

    I'd like to hook 24 LEDs up to one battery pack. I'm going to have the whole array on the inside of a construction style Hard Hat. I want the LEDs to cycle in color, and it would be great if I could use some (or all) of the kind I already purchased. I could probably find someway to get batteries that fit into that 3.8-4.2 voltage range, but suspect I'm unaware of other factors that could mess this up, and I don't want to blow out any more lights than I have to.

    I'm pretty much a total layman at electronics. I'm hoping i can get a decent start with advice from people who obviously know what they're doing.

    Thanks ahead of time for any help
  2. SgtWookie


    Jul 17, 2007
    The link to the LED specifications page you posted didn't work; here it is:
    3.8v-4.5v. 150mW; so approximately 35mA.

    Your easiest solution would be to remove a single AA battery from the holder, and replace it with a straight piece of wire. That would give you 4.5v.