I was in Costco last night and as usual I spent more than I intended. I just can't go in there for one thing and not browse around. I spotted four-packs of Garrity LED flashlights. They have nine super-bright white LEDs. I am very interested in LED technology so I had to try them out. You get four flashlights about four inches long and 12 Duracell AAA batteries. As soon as I got home, I put in the batteries and darkened the room. Wow, super-bright for sure. Never content to leave things alone, I ran one through my bandsaw leaving just the LED module itself intact. It's all plastic so no damage. I hooked up a 4.5 VDC adapter to the exposed contacts and, voila, a little, low-voltage, 9 LED light source. Next step is to paint the lens with a nice, deep-blue paint that is made to simulate stained glass. I've used it before and it dries to a nice, rich, transparent colour. By tonight I'll have twelve of these little pods hanging over my tank. I'll let you know how it turns out.
Oh, and the total cost for this little find? $14.95 for the pack. That's less than four bucks a pop. A dozen AAA cells alone would cost almost that and they're included.
Actually, even if you just need a reliable flashlight, it's a heckuva deal. :)
Interesting idea.
I'd be very interested to see how this turns out with blue tint :)
any pictures yet?
DO NOT attempt this mod. After what happened last night, I have to completely re-think my leaning toward LEDs. I didn't get much of a chance to continue this project over the weekend but I did get as far as disassembling one flashlight. Took it right down to the circuit board with nine LEDs mounted on it. The unit also includes a small resistor to cut voltage from 4.5 to 3.8 VDC. It's about the diameter of a quarter and, overall, about the same size as a plastic soft drink bottle top. I soldered two thin wires to the exposed contacts and hooked up a three-battery pack to test it out. I just left it running to test the makers claim of a sixteen hour battery life. I noticed it on and off over the weekend when I was in the shop and it was burning brightly each time.
Last night, just before heading to bed, I made one last trip into the workshop to make sure I had turned everything off. I don't know what made me go in there when I did but, I'm extremely grateful to whoever or whatever pushed me into that room. I looked over to the workbench and saw FLAMES. The little pod of LEDs was actually on fire. It must just have started because only about four of the LEDs had burned by the time I put it out. The flames were about three inches high and growing. I didn't take a long time to examine then but I will tonight. The first thing I thought of was an overheated resistor but, it looks like the actual LED was the source of the ignition and the fuel.
I did take some pics but I left the camera at home. I'll post the pics tonight.
Short, simple message is DO NOT ATTEMPT THIS MOD.
Good to know. Lucky you went in to look!!!
:-\ Give credit were crdit is due.. I hope you now beleive in gaudian angels !!....... :D :D
wow crazy!!!
Glad you went back to check!
Well, I talked to a lot of people over the last day or so and nobody believes that the LEDs were the cause of this. So, back to the investigation. It now looks like I may have caused the problem myself when I reassembled the initial unit. You can't really see it in these pics but, it looks like after running for over twenty hours there may have been enough heat generated by the nine LEDs to soften the insulation on the red and yellow wires inside the unit. The very end of the resistor looks like it made contact with the metal plate that connects to the red wire. That dead short created enough heat to ignite the plastic. There was no actual damage to the LEDs. In fact, as you can see from the pictures, when I hooked then unit back up again, it worked just fine. So, my faith in LEDs has been restored and the project lives on. I will be stripping these things all the way down to the circuit board and doing away with the resistor. I have a 3.7 VDC adapter so that should work just fine.
These two pictures shows the paint as it is applied and after it has dried with the LEDs behind it. The distortion is all because I used a piece of junk glass covered in old calcium deposits for the test. The colour on the left is sapphire and the one on the right is royal blue. The lights are bright enough that I may have to add a second coat of paint to intensify the colour a bit. The other pics show the thing operating properly as well as the damage.
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Just a thought (something we all should be doing).
Check your basement smoke detector is in good working order!
Quote from: Sue on February 27, 2007, 12:59:34 PM
Just a thought (something we all should be doing).
Check your basement smoke detector is in good working order!
Correction! Check that your smoke detectors on
EVERY FLOOR are working. That is the law now! :)
Since I've decided to continue with this project I have come up with a way to complicate it and I am seeking opinions and suggestions. I'm setting up a sort of Nano cube in a homemade 22 gallon tank. What goes in it will be determined by how well this turns out. The footprint is just about the right size to put about 20 of these 9 LED units spaced evenly over the top. That would make 180 LEDs. Originally I had planned on colouring each individual unit and mounting them over the tank in eggcrate or something similar. Now, the plan is to use the LED lighting system day and night. I'm going to colour individual circles on a piece of acrylic or plexi that match up with the locations of the LEDs. That should leave about the same space between each dot as the dot itself is wide. My idea is to mount the plexi in two rails that will sit over the tank. When the timer decides to switch from daylight to moonlight mode, a small servo motor will pull (or push) the panel the width of one unit on the panel and hold it there. When the timer switches again something that I've yet to think of will return the panel to its other position. So, in one position, white light will shine into the tank and in the other position the blue circles will colour the light. If I can make the transition slow enough, it should be much like daylight turning into twilight turning into moonlight.
What think ye all?
Pretty clever grasshopper, you just need some louvers I would think though, it might be easier to have a jalousie set up with dark blue plexiglass, less fuss and more reliable. You have an interesting mind, you must have driven your parents mad when you were a kid.
Quote from: babblefish1960 on March 01, 2007, 01:20:32 PM
Pretty clever grasshopper, you just need some louvers I would think though, it might be easier to have a jalousie set up with dark blue plexiglass, less fuss and more reliable. You have an interesting mind, you must have driven your parents mad when you were a kid.
Hmm, neat idea. Yeah, I suppose I was a challenge. Oh the stories I could tell. I know my high school chemistry teacher kept a pretty close eye on me. He wasn't impressed when I landed a glass thermometer in his lap from across the classroom. Apparently, it was still hot. ;D
if you do not match your led input to your adapter output, it will overheat the resistors and may create another fire.
i rather put an actinic bulb and not worry about the leds, i tried the same 2 years ago and it just wasnt bright, i also built a few white led only canopies with bigger leds but they still sucked.