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Mondak · 04-07-2004, 07:00 PM

I have been wanting to do this mod for some time and wrote it up for another site where I post sometimes. Thought I would share it here too. I wanted to make a maglite that runs off of Bright LEDs. They use way less wattage than regular maglite bulbs and should run for 5x longer with the same batteries. They also SHOULD be brighter than a regualr bulb.

I actually did this with a 2AA MiniMag Lite and just stuck the LED into the holes, but I was unsatisfied with the results. As such I decided to use my 3D cell MagLite instead. Here is the victim:

Since 3D cells produce 4.5 Volts and LEDs I choose operate at 3.6 Volts, I decided to wire 3 LEDs in parallel with a 12 Ohm resister. I used a ¼ watt, 5% tolerance resister and calculated it’s need using this tool: http://metku.net/index.html?sect=vie...calc/index_eng

First step was to remove the lens cap to get access to the bulb on the MagLite.

Then I unscrewed the cowl that holds the bulb in place and removed the Bulb.

This is when I remembered that I USED to be good at soldering. Other than small things here and there, I am about 12 years out of practice. I will get better one of these days.

I got my LEDs from http://www.lsdiodes.com/. Seems like other folks from this site like them so I used them too. They came in one day even though I used regular shipping. Not too shabby. I choose the 5mm 12,000 mcd White bulbs as the brightest ones I could find.

This is where it gets interesting. I want to reuse the bulb so I can swap out an actual bulb with my LED cluster if I have to. As such the resister has to fit within the cowl and bulb area. After soldering a lead to the end, I hot-glued the resister under LED #1. Please note, I would wait to hot glue anything until after the soldering is done. The soldering iron can heat up the glue when soldering nearby and make a mess.

Looking good – ha ha my soldering should be a crime.

Ok – so I smashed the bulb and was surprised to see the leads still intact after I removed the little blue thing that I think was a resister and the filament. I was going to dig this whole thing out and solder to the casing, but instead, I soldered to the leads. As you know, it is crucial that you get your + and – correct or your LEDs won’t work (remember these are not just pretty lights folks – they are Diodes which only let current flow in one direction. Hook them up backwards and you are in the dark). You figure it is a 50/50 shot here, but I choose the lead closest to the side of the bulb where the notch was as negative. You can’t see it here, but there is a small dab of solder there where the lead is connected to the housing. I figured the one closest to this spot would be the negative and I was right. Not sure if this is standard, but it might be.

I stuffed the lights through the cowl and it is all hooked up and ready to plug back in a screw into place.

All hooked up and in place - /me crosses fingers……

Success!

Couple of thoughts:

I thought this would be brighter than it is. I am not really disappointed with the light output I am getting, I just thought it would be more. Maybe someone can give me some advice on what I could have done. There are a couple areas that may affect this.

I used my Dremel to “frost” the LEDs to see if I could get some more diffusion. They are pretty pointed in how the light comes out and they don’t take advantage of the mirror lens. It helped some, but not a lot.

Another thing, I used ¼ watt resisters and I am unsure if I should have used a lower value or what effect that would have. I don’t really know how to adjust that.

It should be getting exactly 3.6 Volts based on my resister. I am not sure what would happen if I gave it more or how much it could take. I should have bread-boarded this thing first to test, but I don’t have a convenient power supply (read: Lazy). I wish I could see how much brighter they would be with a little more juice.

Let me know what you think or any ideas.

04-07-2004, 07:00 PM	#1 (permalink)
Mondak Industrialist Location: Southern California	How to modify a Maglite to Run on LEDs I have been wanting to do this mod for some time and wrote it up for another site where I post sometimes. Thought I would share it here too. I wanted to make a maglite that runs off of Bright LEDs. They use way less wattage than regular maglite bulbs and should run for 5x longer with the same batteries. They also SHOULD be brighter than a regualr bulb. I actually did this with a 2AA MiniMag Lite and just stuck the LED into the holes, but I was unsatisfied with the results. As such I decided to use my 3D cell MagLite instead. Here is the victim: Since 3D cells produce 4.5 Volts and LEDs I choose operate at 3.6 Volts, I decided to wire 3 LEDs in parallel with a 12 Ohm resister. I used a ¼ watt, 5% tolerance resister and calculated it’s need using this tool: http://metku.net/index.html?sect=vie...calc/index_eng First step was to remove the lens cap to get access to the bulb on the MagLite. Then I unscrewed the cowl that holds the bulb in place and removed the Bulb. This is when I remembered that I USED to be good at soldering. Other than small things here and there, I am about 12 years out of practice. I will get better one of these days. I got my LEDs from http://www.lsdiodes.com/. Seems like other folks from this site like them so I used them too. They came in one day even though I used regular shipping. Not too shabby. I choose the 5mm 12,000 mcd White bulbs as the brightest ones I could find. This is where it gets interesting. I want to reuse the bulb so I can swap out an actual bulb with my LED cluster if I have to. As such the resister has to fit within the cowl and bulb area. After soldering a lead to the end, I hot-glued the resister under LED #1. Please note, I would wait to hot glue anything until after the soldering is done. The soldering iron can heat up the glue when soldering nearby and make a mess. Looking good – ha ha my soldering should be a crime. Ok – so I smashed the bulb and was surprised to see the leads still intact after I removed the little blue thing that I think was a resister and the filament. I was going to dig this whole thing out and solder to the casing, but instead, I soldered to the leads. As you know, it is crucial that you get your + and – correct or your LEDs won’t work (remember these are not just pretty lights folks – they are Diodes which only let current flow in one direction. Hook them up backwards and you are in the dark). You figure it is a 50/50 shot here, but I choose the lead closest to the side of the bulb where the notch was as negative. You can’t see it here, but there is a small dab of solder there where the lead is connected to the housing. I figured the one closest to this spot would be the negative and I was right. Not sure if this is standard, but it might be. I stuffed the lights through the cowl and it is all hooked up and ready to plug back in a screw into place. All hooked up and in place - /me crosses fingers…… Success! Couple of thoughts: I thought this would be brighter than it is. I am not really disappointed with the light output I am getting, I just thought it would be more. Maybe someone can give me some advice on what I could have done. There are a couple areas that may affect this. I used my Dremel to “frost” the LEDs to see if I could get some more diffusion. They are pretty pointed in how the light comes out and they don’t take advantage of the mirror lens. It helped some, but not a lot. Another thing, I used ¼ watt resisters and I am unsure if I should have used a lower value or what effect that would have. I don’t really know how to adjust that. It should be getting exactly 3.6 Volts based on my resister. I am not sure what would happen if I gave it more or how much it could take. I should have bread-boarded this thing first to test, but I don’t have a convenient power supply (read: Lazy). I wish I could see how much brighter they would be with a little more juice. Let me know what you think or any ideas.