My wife and I had a need for some UV lights a few weeks ago (we had a booth at a gun show and needed to check money) so I picked up a batch of 5mm diodes and wired them up without a body to get the job done. Now I’ve discovered those little AAA C8-mini’s that come with a 5mm LED so I ordered 3 of them from DX for $12. I’m wondering about how much UV they’ll put out once converted to 5mm UV. Will a single 5mm diode on a single NiMH AAA work well for checking bills or will I need to use a driver (can you even drive 5mm’s) or get a more powerful UV LED?
For safety’s sake I’d rather not use a 10440 incase one or more walks off at the next show but would a 10440 make a big increase in light output? I’ve not tried one of them at 3.7v, is it to much?
One other question, would it be better to use a few emitters in each light without the reflector or use one diode in the reflector?
You can drive 5mm LEDs, they don’t need so many 7135 regulators though, so I’d desolder the excess and leave one. You will need a driver to product the higher voltage anyway for 5mm UV. I don’t think a single NiMH will be enough voltage to direct drive.
I am able to run them off button cell batteries, does that mean I’ll have to run a 10440? Will a 105c work at 1.2v, even just at 380mA? I have no idea the brand of these 5mm UV’s I got, any guesses of the forward voltage/drive current?
The ones I have are 3V (3.6V max), current is very low ~20mA. So the Nanjg 105c would suit a parallel setup (I have one driving 40x 5mm white leds, powered by 1x 14500). Lowest voltage of 105c is 3V; any lower and the driver will make the LEDs flash with low-voltage warning.
105c is a linear regulator…so it uses a 10440 4.2vdc battery, regulates it down. To use a 1.5vdc battery you need a boost driver, the driver in the mini C8 is just under 17mm, they do sell 17mm drivers. I have 5 Nanjg 110 which is a booster circuit
Actually people have taken single 7135 chips and make a 1 mode (off/on clicky) it’s not a pretty setup, but inside the plastic pill you won’t see it
Iirc the front lens is plastic. It was suggested to place a dab of hot glue on the center and give it a pull. Or just smash that sucker out since you won’t need it with the TIR.
I gave it to my son, no mods needed: cool white tint is pretty ok, and the throw is really good for its size. I measured 15 lumens output on an alkaline (exact what I wanted for my son). The circuitry is very basic too, they even skipped the inductor and the cap, just a resistor and a little component marked CX2601, that apparantly does the voltage boost (I'm an electronics noob):
I pressed the lens out as well, but now that I reassembled the light it unwantedly pops out more easily when screwing on the head (that does not have a 'stop'). But the 'golden' ring is screwed on the same threading as well, so you can use that to fix the head in the right position so that it does not pop out the lens anymore (I am sure no-one understands what I am trying to explain here but never mind :-) ). It looks a bit different from the mini-C8, that's all.
Back to OP, is this modding for modding’s sake or to get functionality (check dollar)?
If for second purpose only, I don’t see why go through all this trouble. Those 5mm UVs are readily available in 3xAAA format with long runtime, nothing else to worry except pop the AAA primaries in.
I think there still is a point in the OP, those uv-leds come either in 3xbutton cell lights, or 3xAAA, while the 1xAAA form would be my favorite. Not sure if the 'thrower' reflector has any advantage here, but the price of this light is good and it looks fun.
Oh yes they will, good point, I made a small zoomie light with a 365nm Ledengin Z1 led and the stock PMMA aspheric lens of the host was unusable, I had to order a glass lens for it.
