Hi,
I am thinking of building a light using a 3d printed case and harvested vape batteries. Certainly nothing with high power, I was thinking of using a single amc 7135 to limit the current because I still have some lying around. I would use a tp4056 for protecting the batterie. As for the emitter, I still have a Cree XP-L on a 16mm star, which could work, but I am open to different suggestions. What do you think of this as a concept?
Its supposed to be a small and easy to use flashlight.
What do you think of this concept? I am guessing I would get something around 200lm out of the xp-l at 350mA, is that correct?
I don’t know enough to provide feedback on the engineering aspect, but the idea sounds good. Given how low the drive current is, I would go for an ultra high CRI emitter instead of an XPL–you won’t get a ton of output anyways, may as well make the light as high quality as possible.
Thanks for the idea. My reasoning was
1: xp-l is already here, might be ok as a poc.
2: given that the current is so low, at least get the most lumens out of the small Power Budget.
But your reasoning is understandable too. As i said, I am open to suggestions.
I have 2 headlamps that I bought for dollar store that I modified from simple resistor driver to a single 7135 and LH351D emitter. The output is good for close range desk illumination.
For a low current linear driver like a single 7135, you want high Vf, high output emitters to make the efficiency as high as possible.
Nothing wrong with ancient emitters. I’d rather have a decent looking beam, ie, not overly green or rainbowy, not blue, etc., even if it’s not the highest CRI, etc.
If I’m just grubbling around under a counter for something, I don’t care that my Tacklife has an arctic-blue beam. I use it for a minute tops.
I don’t need to see the exact shade of katchup that’s in the bottle. All I need to see is whether/not I even got a bottle, and if so, read the dates and use the older/-est one first.
You do you. You got an XM-L? Use it. if you’re gonna go all 519 or whatever, then just toss the XM-L because then you’ll never use it anyway. Next “need”, you’ll again get the by-that-time 719C or whatever’s the new Golden Boy of the LED world.
Unless it’s a green-blue 1B or something just as hideous, who cares? Like I said, you do you. If the XM-L was good before, it’ll be good now. They don’t get stale or go moldy or nuttin’.
I forgot to mention that I am using a solid peace of brass 15x7x50mm. I drilled and threaded 2 holes to mount the emitter and drilled some more holes for the cables and to mount the heat sink to the body. It might be a little overkill, but I wasnt certain how much heat the emitter would produce. I also lapped the emitter and the heat sink and put thermal paste on it. Now I only need the batteries and this should be complete. I will post pictures after everything is done
I dont need RPP, as the battery will be soldered to the TP4056 module. On this board is also a chip which does overdischarge protection and overcurrent protection. Thats what I meant when I said battery protection. I should have mentioned that, but it was late yesterday so I forgot.
Thats the current version. The batteries have a capacity of 400mA and are wired in parallel. I have done my the iterations of my design in PLA and am currently printing the final version in black PETG. The switch is mounted on the side, the USB-C port on the back. I changed a resistor on the TP4056 module to limit the charging current to around 0.5C to protect the batteries. Its quite heavy, because of the brass “heat sink” and the weight distribution is a little of because of it.
Still I am fairly happy with it for a complely custom light.
Here is the final version. I added a blue LED which is connected to the TP4056 to indicate a fully charged LED. I sanded the case and put a coat of clear coat on, just to try it. I am fairly happy with it, its just a bit bulky.
