something like this but with more amps… 3a would be nice
http://pages.ebay.com/link/?nav=item.view&id=131237426446&alt=web
Like this one: lck-led.com - Informationen zum Thema lck led.
Got it myself with 2 18650 - works great.
I have seen setup like this before: Single XP-G2 + zener modded Nanjg 105C driver + two 18650 in series, and the outcome didn’t turn out well. After running the light on high mode for about a minute the LED started to flickers due to driver overheating.
Nanjg 105C and BLF17DD drivers are not buck drivers, but they are just linear drivers, meaning that these drivers cannot step down the voltage. So when your input voltage (8.4V) is significantly higher than the output voltage (3.0~3.8V) the “excessive voltage” - or more appropriately the excessive power will be wasted as heat and something might be burned. Not a good idea, really, so using a buck driver is your only choice in this kind of setup.
But using zener modded Nanjg 105C or BLF17DD to run a 6V emitter like MT-G2, XHP-50 or XHP-70 is fine, because the input and output voltage difference isn’t that much anyway.
I am just trying to build a light with two 18650s with a xml2. I have a p60 that allows up to 18volt input.
That’s a buck driver and it’s what would work correctly for you. Keep in mind the size of the driver when looking for the correct one and the output. Here is a list of the Buck drivers at RMM’s site, he is a great guy and ships super fast. He also has the emitters on noctigons so that if you want to go with much higher amps you can do so without frying them.
look at my post above yours.
You are building a P60 dropin for a two battery light? If that is correct then it’s the 17mm driver that you need.
hmm that $18 driver version is kind of pricy they rest will not fit a p60…
It’s hard to find a smaller buck driver. I know they make a bunch of them and put them in lights but they don’t seem to sell them retail. I looked around for you at a couple places that I buy drivers from but nobody seems to have them in stock. One nice thing about the $18 driver is that he will program it for you so you can pick your own modes. He has to make these drivers himself so the price is really pretty good considering his time involved. Still I know what you mean, it’s a lot of money to drop into a light just for a driver.
That's why the MTN-MAXlp was created. There wasn't ever a 17mm buck driver that would do more than ~1A and still fit in a P60. There was also a lack of high-powered buck drivers that could fit in 17mm lights like the UF-1405.
If the price is too high then you can just get the PCB and build your own. I posted the PCB, parts required, etc., including the board needed to program the MCU on this forum. Here is the post that will tell you pretty much all you need to know.
Another alternative is to take a driver and modify it by adding a resistor to it. This one looks like it could be modified. I have modded a ton of drivers but I’m really a hit and miss kind of guy when it comes to modding buck drivers for single emitters.
If you already have a driver in the light and just want more amps you could take a picture of it and maybe someone can help you out. If it’s one I have worked on I might be able to help myself. I would try and mod the driver you have if it was me, but then again I have a large box full of drivers that I have killed too. I have killed at least a hundred emitters too! So there are people here that know a lot more about them, at least how the electronics work.
This really looks like you should be able to stack a resistor on top of the R150 and get more amps, but I haven’t worked with it.
Right on and it explains why I have a bunch of lights that I modded to take a single battery. It was easier than finding a buck driver for them. Now that this is out I’ll probably go back and mod of few of them with it. Thanks for the link. I’m just getting back to modding and need to place an order with you soon. Once my shoulder is healed up I’ll be hitting it hot and heavy again. I have a bunch of lights for other members that I need to get caught up on. Your site is really a godsend and I’m not kidding either!
I have three projects
- Have a UF-V8 2x18650 want to put an xhp70 in so I need a (8.4v/6v driver hopefully with out noticable pwm does not need to be super hot, would like ramping or lots of levels) and a copper board for it.
- a 6v driver for a s7 clone. ( do we have access yet to 6v boost drivers) aka single cell like the jm35?
- “regular” driver for the other s7 for a 3c XML emitter
Any thoughts
Non need to be fire breathers I am more concerend that”high/turbo” is actually usable for long times.
what about running a 6v XM-L2 with DD and some tame 18650’s?
Just so you know, the “Zener Mod” only limits the input voltage to the mcu. It has no effect on the voltage feed to the led. The purpose was to allow a nominally single cell driver to control 6V worth of led.
They would need to be really tame ones and you would need to use very thin wire too. It can be done, I did it with a DRY driver once. Although the DRY driver had more resistance in it than the BLF drivers do.
The strange thing is the XP-G2 was able to work in such configuration for about a minute before the light started flickering. The XP-G2 didn’t just get killed instantly, so I guess the LED wasn’t actually seeing 8.4V feeding to it?
If you were running a 105C then the 7135s were actually regulating the voltage to the LED, it's just that the amount of heat generated is way too much.
FET Zener mod allows maximum current and voltage to the led. As RMM says, with a Zener modded 7135 driver like the 105C the 7135’s burn off the extra voltage as heat. Likely it was overheated 7135 chips that caused the flickering. With fully charged cells more than 4V is turned into waste heat and they aren’t reliable much over 1V without extraordinary measures that might get you to 2V.
Alright I have a better view of it now, thank you very much to both of you.