KevinL
Flashlight Enthusiast
OK, title's overly simplistic.
I have a 3C Mag running 3x Lux3s. This light was put together with the assistance of a custom heatsink, the success of which went on to spawn a whole generation of multi-LED mods and a whole new array of heatsinks designed for these mods. The amazing thing is that when I first built it, there were only a couple of commercial lights/drop-ins with 3 or more LEDs... it was nearly impossible to find a heatsink suitable for this mod! (I got one customized to my specs - after that then came the flood of intrepid machinists selling the sinks).
History lesson aside, I'm now thinking of giving it a facelift in 2008. The heatsink is the same as it's always been, flat slab of aluminium. I'm gonna stick four Crees onto it. The old light has been a direct drive setup on 3 NiMH, and likely the new one will be too.....except that I'm exploring regulated options.
What's the best way to drive 4 Crees at 1A each? I've thought of a number of solutions but none seem to produce the results I want....
1. Direct drive the way it's always been. Yes, its's the simplest design, it will get me (roughly) there, but the disadvantage is that I have no assurance the current will be what I hope it will be. It's very hit and miss if I'm shooting for a 1A drive current. I'm not too worried about overdriving, I AM very worried about underdriving. What's the fun in an underpowered LED? More lumens, bring it on!!
2. Taskled D2DIM: direct drive, 3 NiMH should feed the LEDs enough current for them to do the job. D2DIM works to dim it. Again same disadvantage as direct drive - can't be sure of the current going to the LEDs. In addition, the D2DIM has a limit of 3.4A, and I want 4A combined total to the LEDs.
3. AMC7135 based drivers. Glorified resistors as they have been called, and they don't boost current. Plus specs and documentation are next to nonexistent. You pay for what you get, I suppose. If only everybody documented like Taskled. I can't even figure out the output voltage from the sketchy info available on them.
4. Dual Fatman drivers. I love these, except I can't find 50K log pots. The electronic shops in my area look at me as if I'm nuts. (ok, probably language barrier involved, too). And I need to drill my Mag. I can probably get it drilled no problem, but can you control two Fatman drivers from one pot? Plus they get expensive.
I'm thinking of wiring each driver to 2 LEDs in series. This way, each only needs to boost 3.6V nominal to ~7V output, which should be within the Fatman's capabilities.
Cons.. they're expensive, I'm looking at $50 in drivers ALONE.
soooo...... given the limited selection of choices, should I just slam 3 high-current SubCs into the light and let the chips fall where they may?
I have a 3C Mag running 3x Lux3s. This light was put together with the assistance of a custom heatsink, the success of which went on to spawn a whole generation of multi-LED mods and a whole new array of heatsinks designed for these mods. The amazing thing is that when I first built it, there were only a couple of commercial lights/drop-ins with 3 or more LEDs... it was nearly impossible to find a heatsink suitable for this mod! (I got one customized to my specs - after that then came the flood of intrepid machinists selling the sinks).
History lesson aside, I'm now thinking of giving it a facelift in 2008. The heatsink is the same as it's always been, flat slab of aluminium. I'm gonna stick four Crees onto it. The old light has been a direct drive setup on 3 NiMH, and likely the new one will be too.....except that I'm exploring regulated options.
What's the best way to drive 4 Crees at 1A each? I've thought of a number of solutions but none seem to produce the results I want....
1. Direct drive the way it's always been. Yes, its's the simplest design, it will get me (roughly) there, but the disadvantage is that I have no assurance the current will be what I hope it will be. It's very hit and miss if I'm shooting for a 1A drive current. I'm not too worried about overdriving, I AM very worried about underdriving. What's the fun in an underpowered LED? More lumens, bring it on!!
2. Taskled D2DIM: direct drive, 3 NiMH should feed the LEDs enough current for them to do the job. D2DIM works to dim it. Again same disadvantage as direct drive - can't be sure of the current going to the LEDs. In addition, the D2DIM has a limit of 3.4A, and I want 4A combined total to the LEDs.
3. AMC7135 based drivers. Glorified resistors as they have been called, and they don't boost current. Plus specs and documentation are next to nonexistent. You pay for what you get, I suppose. If only everybody documented like Taskled. I can't even figure out the output voltage from the sketchy info available on them.
4. Dual Fatman drivers. I love these, except I can't find 50K log pots. The electronic shops in my area look at me as if I'm nuts. (ok, probably language barrier involved, too). And I need to drill my Mag. I can probably get it drilled no problem, but can you control two Fatman drivers from one pot? Plus they get expensive.
I'm thinking of wiring each driver to 2 LEDs in series. This way, each only needs to boost 3.6V nominal to ~7V output, which should be within the Fatman's capabilities.
Cons.. they're expensive, I'm looking at $50 in drivers ALONE.
soooo...... given the limited selection of choices, should I just slam 3 high-current SubCs into the light and let the chips fall where they may?
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