Great idea. I’d add a jumper on the component side to configure if e-switch signal should be taken from signal tube ring. That way it could be easily adapted to other e-switch hosts.
Is it necessary to use buck-boost? It is more complicated, and less efficient than buck.
At low V battery have small amount of energy. So efficiency of buck may could give more than work at low voltage with buck-boost
Thanks! There are currently no plans for a group run though, but we'll see..
In this case, the RGB channels are driven directly from the MCU and are only meant for dim aux lighting; again the original intent was based on the use case presented in ToyKeeper's Anduril and similar firmwares. It's not difficult to use those pins to control something else (small fet and resistor, or it's own 7135 etc), but this will probably not be the main focus of the lume driver boards. Design will be open sourced and you will be free to modify it to your own purposes, though you will need to adapt your own firmware too :).
Thanks, but there are no plans to add a jumper for this specific board, since this board was optimized for the FW3x, and may not fit many other flashlights. Other E-switch hosts will do well with a different board design, perhaps in the future. Design will be open sourced, and anyone will be able to design their own for their custom use :).
Thanks! However, Buck-boost here is no more complicated than a buck, does not use any additional components in this case, and in the targeted operating parameters, only very slightly less efficient for a buck with similar resources (but more efficient than cheaper non-synchronous bucks for example, or cheaper synchronous bucks). Buck-boost is a necessary however, and should always be done in this case as good engineering design. In most scenarios, this BB will be operating in Buck mode, but take for example the scenario when temperatures are sub freezing, battery is a little old, and isn't completely full - this is a use case for me such as when I'm camping... boost mode operation is required then.
It is true that there are many more dedicated buck regulators with small footprint on the market with high current capabilities, however it's still a little bit of a conundrum, as the higher the input current increases, the lower the battery voltage will be, necessitating the need for a boost even more. For higher power requirements, I'll refer to the GXB series of drivers. Finally, there are also many inefficiencies in flashlight systems, especially as flashlights get older (contact resistance being very significant), which Buck-Boost operation will hopefully help mitigate.
Wow, there was longing for a driver capable of both high outputs and high efficiency while having BLF UI. And your driver delivers that. I’m sure there will be many people interested, especially once it’s available in a more standard format as well.
The lack of RGB aux has kept me from buying FW3A - you just added this while improving efficiency. Great. 
Though for me the sense resistor in series with FET is actual misfeature, I have a light that steps down in less than 10 seconds and I could easily go with even less than that. And 200 mV drop at 10A is a lot.
I hope these will be more available than the previous drivers…
This. Nice work again. 
Regarding the sense resistor, true, it's not something I'm too happy about either; perhaps I'll figure out a better solution without adding another big FET (which I guess is possible, but not very elegant..). However, I think considering how fast the FW3A begins stepping down at Turbo, perhaps with a less bright turbo, it may be possible to have the light running at this lower turbo mode, but for a longer period of time. Maybe less wow, but could actually be more useful? I think some very low V_fwd LEDs may benefit from this too. I hear that typically running some Nichia 219 LEDs require a change in the FW3A firmware to run turbo at 50% duty, or for the user to use a lower-drain battery to mitigate.
I’d definitely be interested in a couple of these for my FW3A’s, and also some in other sizes if they get made, SP40, A2S etc.
Some users want dimmer but longer turbos, some want them brighter but shorter. There is no duration that’s good for all. Myself I’m one of the more extreme bunch, for me even 5s would be enough while many consider sub-10-second turbos to be too short. Some don’t want turbo at all and want the highest mode to be so low to last until the battery is empty.
I don’t believe that increasing or decreasing flashlight power output makes it more useful - it will always be more useful to some yet less useful to others.
And that’s why I think that firmware is a better place to manage that. Because it’s easier for users to adjust it to suit their needs. As of now it still requires re-flashing. Programming pads make it easier but it’s still not for everyone.
Maybe one day it will be possible to just configure Turbo output like it is possible to change ramp max now.
May I ask what buck boost IC you are using? When I was looking through Mouser for a design of my own I didn’t find anyone that could do 3A.
Edit: No worries, I found it. I looked at that one but within the first three lines of the datasheet it stated output current 2.5V to 3.3V as 2A. I didn’t read the part under the description where is stated “output currents up to 3A are supported”. I ended up selecting a different IC with somewhat similar ratings for mine.
Great Loneoceans!! It is always a pleasure having news of your work.
Very interested in this for skilhunt H03/04s and also other lamps.
You mentioned ultra low moonlight in the previous thread, how ultra ? current zebralight (~0.07lm) or past zebralight ultra (~0.01lm) ? I’m also curious about the finesse of adjustment of the moonlight levels (a firmware thing ?)
Could charging be integrated ? e.g. for H03/04R with USB magnetic charging port.
If particular attention could be payed to the driver being 100% silent that would be great, electronic noob here but it’s both a design and quality of components thing right ?
Any estimate on how long until this becomes available?
This is look'n real good! Sorry if I missed this, but does it fully support smooth ramping? We usually use a 150 level table. If I understand this, the first 3 amps is regulated, then after that the FET kicks in. This is similar to how we treat a bank of 7135's. The linear regulated driver in the new Noctigon K1 works similar, from what I understand. Up til now, I don't think TK released any of the 1634 Anduril config files. All I know of is 2 Anduril 1634 lights - the D4SV2 and the K1.
Since it's a OSHPark design, I'm hoping we can build up our own, but that depends maybe on how small you are going with parts. Think there are some 0402's there. Not sure what the FW3A driver size is, but scaling up the size should be easy - just keep the parts as-is and expand the outer space - we've done this before.
So are you planning on developing the hwdef and cfg files for Anduril?
Thanks everyone for the feedback; I appreciate it! There is no specific ultra-low moonlight for this driver at the moment, mostly to keep things simple. I hope the lowest mode setting should be low enough; I'll take more measurements soon. However, it will be easy to add in hardware to enable truly very low modes if desired.
I also understand the concern about the flashlight being silent - I didn't notice any issues on my dev board across different power levels, but need a little more evaluation on the form factor board. Typical sounds come from a PFM or burst frequency, which can cause some sounds if it's below ultrasonic and if the devices (typically inductor) vibrates too much. There are no plans to add integrated charging; it can be done, but I think is beyond the scope for this particular design. I really wanted to keep this as simple as possible and to keep the BOM cost down without sacrificing on the engineering.
Not yet; please follow this thread and I'll update when I can, thank you!
The FW3x has roughly 22mm driver cavity. The smallest parts on this board are the 0402 passives and a SOT723 transistor (along with the other QFN parts). It will be challenging to put together if you don't have some sort of magnification, but should be pretty easy with some experience and hot air. At the moment, the lume1 board for the FW3x has only components on one side (with only the spring being on the other side) - hopefully that helps.
Yes it supports smooth ramping. Also, yes the first 3 amps are regulated; the FET is for unregulated Turbo, and you are correct, similar to 7135s. I have a primitive firmware I wrote to test the hardware and it serves as a simple firmware for now, but I am currently working on the config files for Anduril... hopefully I get it right!
Here's a preview of things to come:
For those concerned, I did put some tape around the flashlight so as not to have it scratched by the clamp. I think this PCB colourway works quite well with the FW3C.
This looks great. I am looking forward to hearing the results of your testing.
If there is enough interest, are there any resources accessible to the community for building a batch of fully assembled boards, even if such a group buy would need to be run by someone else?
Yeah. that PCB color is cool!
Thank you thank you thank you. That’s spot on real for me.
I accidentally stuffed 1 of my FW3A’s drivers. This is exactly the replacement driver it needs. And maybe even the rest of my shelf queen FW lights… Great work loneoceans!
Wow another new driver from loneoceans! This one looks very nice, I like the clean design. I wish it is complete soon! Unfortunately I do not have fw3 light yet, but may have to buy one. Do you think it make sense for non-esiwtch flashlight also?
I am so excited to see this board! It will deal with my biggest wish for the FW3A - replacing the linear topology with a buck boost which will improve the efficiency of the light at the most commonly used power levels!
Secondly, aux LED support is awesome!
Keep up the good work!