I did a little tweaking on my light today. Braided the tailcap and got the reflector sitting down properly.
Three of the emitters, though not off center enough to notice, were off enough that the reflector was sitting on top of the raised part of the centering discs. This caused the bezel to not tighten properly and leave a gap. I removed the three offending discs and sanded the raised part flush. Since the other six were still intact, the reflector centered itself nicely and the bezel threads down tight.
I remembered I had some UCLp AR Acrylic Lenses for my COURUI that LinusHofmann brought up in his COURUI thread. https://budgetlightforum.com/t/-/23051?page=2#comment-509979 I had ordered two, and they sent me three...and they were the perfect fit for this light.
These are really nice lenses, and they come in large sizes from flashlight lens.com.
When you install them, it looks like air, like nothing is there, with a Light transmittance: 97%
If you hold it just right, you can see a pinkish tone from the AR coating.
Now that I've got everything just how I want it, this light definitely earned its clear bootcap award.
Glad to hear you’re happy with the UCLp AR lenses, I’m looking to outfit the worthy lights in my collection with them. Expensive, but worth it IMO. I know they’re not glass, and some people just won’t like that, but their performance metrics indicate that it really doesn’t matter that they’re plastic. Combined with the fact that they’re almost impossible to shatter, I could see these performing phenomenally well in EDC lights, or really any light that sees a whole lot of abuse.
I’m not worried about scratches. Big lights like this don’t end up in pockets and when you set them down on their heads the bezel keeps them from contacting the ground. These are the only AR lenses I know of that come in the larger sizes. If flashlightlens.com backs them, they’re good.
When I started out, I had no idea what the output was going to be in this light. If it had been under 2A per I would have used XP-G2.
When that 12 XML light arrives, I’m going to jury rig it with the stock emitters in place (connect everything externally from the front) to get an idea of the output with 6P2S. Then I’ll decide whether to go XPG or XML.
I’ve always had good luck and fast shipping from KD. I ordered the one from DX. I really didn’t want to, and it might have been a mistake, but I’ll be able to let anyone know whether it really has XM-L2 in it. I’m kinda doubting it.
That is a monster mod! great details in your pictures too. I especially like the one where you cannot see that the lens is there. (It is, right?) Thank you for sharing it like this.
Driving a different number of emitters or different types of emitter will probably end up with one of the circuits receiving more juice than the other circuit, which may not end well for a few of the LEDs. It is best to have them as balanced as possible.
I can't remember my calculations, but I think that "as is" (4.3v 0.25 watt zener diode, 200 ohm resistor) the zener mod may be over the limit with 6S cells but I think we could work around this easily due to the low MCU power consumption. However, the 70N02 FET is only rated for 20 volts, so 6S is out of the question. There may be an FET out there that can work that's rated high enough, but I don't think this one will work.
Also, I would think about wiring the LED+ leads directly to the contact board instead of running them through the driver, I'm not sure how much the traces on that thing will appreciate 10A+ loads for extended periods of time.
Thanks Richard.
I never even occurred to me to just wire the LED+ leads direct from the battery. I did that on my COURUI master/ slave setup. It sure makes things easier than trying to solder a bundle of wires onto a tiny little pad. I’ll rewire them tomorrow.
You can but from my experience it’s not really worth it at all. You don’t get that much throw and it ends up being a funky beam with lots of rings.
I am planning to try again with a 4x emitter that is the same size as the OP. It has four circles that don’t connect to each other. I have another that someday is going to get four XP-G2’s dedomed and four separate aspheric lenses.
I moved the LED+ wires from the driver pad and reconnected directly to the battery input. It was a bit of work. I had the setup so well constructed that I had to take the whole thing apart.
I reconfigured everything, and now it has even more copper incorporated in it. That's always good. I had a flood of relief after I put it all together and it still worked. You know how that can go.
Now for now for the scary news.
This time I popped in three hi drain Sony US26650VT and got a tail reading of 13A.
That's a total of 39A !!! 4.3A per emitter.
I shut it down quick. I never thought I'd be saying this, but that's too many Amps. I'm going to stick to the KingKongs to be safe. They've got more capacity anyway.
Richard! If your reading this, you've got to develop a heavier duty version of this driver. This is insane!
How long is my poor little tail switch going to last?
At 13A the driver will be just fine (but the rest of the light might not be.)
I wouldn't sweat running the 70N02 FET at 20A-25A. When you said 30A before, I thought you meant 30A through the driver, which would be at the edge, but 13A should be fine.
Ohms law says:
Volts = Current (Amps) x Resistance (Ohms); or as more commonly expressed: V = IR. So, we can see that there is a direct relationship between voltage, resistance, and amperage.
You are measuring 39A at I'm guessing around 4 volts at the emitter (it is probably lower than that, but we'll just use it because it's easier math!) We know that you are putting about 12 volts through the driver and the emitters are wired 3S, so they each see about 1/3rd of the series voltage (4V.) But, what matters is the driver, switch, and wires are only seeing 13A. If you tried to 1S6P wire those emitters, the wires, switch, and driver would be seeing the full 39A. Resistive loss (heat) increases as amperage increases, which is why 3S makes much more sense here. You can carry twice as much current in the same size wire if you double the voltage. Of course, as the voltage gets higher there can be other issues (arcing, etc.) but as long as you remain 'in spec' then that won't be an issue.
