How to upgrade emitter...

..and add some kind of regulation to this flashlight?

Hi guys, I'm new here so take it easy on me! :wave:

I'd like to tackle my first flashlight project, so here it goes.
Firstly, I apologize for the cell phone pic but it's the best I can do at the moment.




This is a Cabela's 3D Mag-style flashlight that is supposed to have two 3 watt Luxeon LEDs.

The emitters are apparently directly driven because the only thing on the PCB connected to the heatsink is two large resistors and a click switch (of unknown capacity).

The round relief cut into the heatsink measures ~21mm.

The emitters say "LUMILEDS" and I know nothing about them so I'm hoping someone can 'shed some light' on them. (bad, bad, I know )



What I would like to do is max this baby out with some up-to-date LED technology and also add some kind of driver? circuit for regulation. I'm competent with soldering and know my way around PCBs and ICs. I also have decent machining and fabricating ability but I would like to keep this project fairly simple if possible since it is my first!

I think I would like to stay with the 3D alkaline/NiMh batteries unless someone can present a compelling argument to "upgrade".


Looking very forward to any and all suggestions. This is a great forum!

For LED's, just remove the originals (may be really hard to impossible if they are epoxied) and replace them with any LED on a 20mm star board. For the reflector to work properly, replace them with a Seoul P4 LED U bin. You could also use a Cree but who knows what the beam will look like. Make sure you use thermal grease or thermal epoxy between the heatsink and the LED. For regulation, two of these should work well with 3x NIMH. Connect one to each LED. You can find these individually some places I'm just too lazy to look right now. Try DealExtreme for them.

:welcome:

The SSC P4 emitters are the best replacements for your current Luxeon LEDs. They should work best for the reflectors. The U-bin emitters are recommended.

Like the heat sink of the light. For drivers you could use 7135 based circuits (one circuit board per emitter). You get them in multiples of 350mA (350, 700, 1050 etc). Do not use multi-output boards as they may go out of sync if more than one is used.

Good luck with the mod.

Thanks a lot guys!

I'm busy researching this.
I have much to learn and it's more than a little daunting. Man, there's a TON of info and it seems the more I read the more confusing it becomes.


I have a few questions...

1. How critical is the reflector geometry(?) to the success of the emitter change? What I'm wondering is why does the reflector matter in the selection of an emitter? Is it a size constraint or something else?

2. With all the buzz about the SSC P7, would that be feasible? :naughty: I somehow doubt 2 -P7s would be practicable because of the current draw and lack/problem with finding a driver/s. How about replacing/fabricating a new heat sink and use 1 P7?

3. How much of an improvement can I expect to gain in brightness and runtime over the existing Luxeon LEDs? If the SSC P4 is the easiest direct replacement, will that be a noticeable improvement?

4. Is the Cree Q5 not worth the trouble?

5. Are there any other options that might be a little on the 'wild' side? :devil:



ohh, these 'stars' (PCBs) are simply held in place with two Phillips head screws and no thermal paste nor epoxy.

1. In some cases it is a matter of size (a reflector won't fit an LED) but usually its the case of a crappy beam if you don't use the reflector made for the LED. Seoul P4 and Luxeons are basically the same so it they will both have the same beam in the same reflector.

2. I can't see two P7's in that unit. If you want to go with one P7 then just get a maglite. There are already heatsinks made for it so you won't have to go get one custom machined. If you really wanted to put a P7 in this you probably could but I wouldn't.

3. It depends on how hard the Luxeons are being driven right now. The current LED's, like the Seoul P4, are twice as efficient as Luxeons. That means if you drive them at the same current, you get twice the brightness with the same runtime. Or if you can get them the same brightness as what the Luxeon's were, you get twice the runtime.

4. I wouldn't go with the Cree Q5. The Seoul P4 U bin uses the same die as the Cree so they are more or less the same in terms of output.

5. Not really. For wild, go with a Maglite with a P7.

For a driver you might want to look at the Shark from the Sandwich Shoppe. You could add a Remora to get modes. That might be a little overkill for this situation though.

When you do replace the stars, make sure you put some thermal paste (you don't need epoxy if they are held down) so the LED's can run cooler.

Thank you very much for your time and knowledge Spencer. (and CampingLED ! )


I've been a "flashaholic" since long before this forum came into existence but I've only ever purchased them. Since recently discovering this forum I have now found an amazing resource of knowledge and people who share this odd little interest that I've kept to myself for all these years. Because I'm an incessant tinkerer, I can't help but to look forward to some creations of my own!

I've got more research to do but I'm out of time tonight. If anyone else would like to offer up any other ideas for this MOD then please don't be shy.

Thanks again.

CampingLED said:

:welcome:

The SSC P4 emitters are the best replacements for your current Luxeon LEDs. They should work best for the reflectors. The U-bin emitters are recommended.

Like the heat sink of the light. For drivers you could use 7135 based circuits (one circuit board per emitter). You get them in multiples of 350mA (350, 700, 1050 etc). Do not use multi-output boards as they may go out of sync if more than one is used.

Good luck with the mod.

Click to expand...

I would use these components if it was me. I think I'd go 700mA per LED.

The Seoul p4 is the safe bet. If you want to be adventurous I can send you a lowly p2 Cree XR-E to test with the reflectors, if it works well you can grab some premium bins to use.

Be aware that seouls have a positive slug (the base of the emitter), so if your star has a base that connects through to the (-), you must isolate it. Either use a Seoul already on an isolated star, or add a very thin layer of isolation to the grounded star.

They also need about .015" to .030" of lift to be at the same focal point as a Luxeon. Use a small copper disc, or a thicker star if possible.

Since you will be using stars, the positive slug of the LED doesn't matter since the star is isolated.

Around 0.030" lift would place the LED at the optimal focal point but it should work fine without it too.

You can also try these drivers too.

Gunner12 said:

You can also try these drivers too.

Click to expand...

I have some of those drivers and they don't perform well in a 3 cell configuration. They actually need 4 as a minimum to give a good output.