thefreeman’s HDR Anduril 2 high efficiency drivers - update : FWxA boost driver

Found some pic of Q8 insides
Plenty space for 10+mm coil.
Q8 driver diameter about 47.5mm
Here Texas Ace FET+1+N Q8 driver , but you can download source code and use only outlines and drill file ;))

That’s perfect, thanks.

Hi thefreeman. Very interesting progress over your designs. Also I am impressed from your skills in electronic design for that little time you are here in forum. It is interesting about that dual buck driver which you are designed. More interesting is how do you share the current between two DC/DC converters. Are they work in parallel or just that buck drivers are used in dual channel configuration for high dynamic range?
About current spike there is problem with opamp feedback. It is very slow to go in regulation for that little time. Solution is to be used better high speed OP. Some time ago as you I was interested to design some boost driver with MP3431 and TPS61088 and tried some PSpice simulation and that current spike is very obvious. See my post in thread about Convoy MP3431 driver.

I think we can share some ideas about improvement of that design.
About FW3A I have the measurement about tail PCB because some time ago I designed PCB for tail swich mod with better push button. Also I made the PCBs but the now because of shortage of components I can’t find buttons in stock now like many Attiny85 chips.

Thanks for the compliment :blush:

It’s basically two independent buck LED drivers controlled by one MCU.
I guess there are two ways to make a tint adjustable light, either use one power channel that shared via PWM between two LED channel (e.g. Sofirn IF25, tterev3’s drivers), or use one power channel per LED channel.
Anduril only supports the second case, and IMO it’s the only viable way with DC-DC converters otherwise there can be audible noise when the power channel is shared.
That said the HDR function with tint ramping is not supported yet in Anduril.

Op-Amps with the required precision have a fairly low bandwidth, the MCP6V66 is a little higher I think but I’m not sure that will change much. To achieve good stability with good bandwidth I think the right way is to use a type 2 compensator instead of type 1 used currently, but determining the right values to use is still a bit too advanced for me, there is also the 2 additional components cost.

That said with the TPS61288 and TPS61178 the output was stable with a low value for the compensator capacitor and no spike at start up.

Is that a battery contact in the center of the board? Do you consider a spring contact instead? That would free up a little board space. Using just a PCB contact seems iffy, especially at high current. There was a guy on CPF who was an aircraft machinist or something like that, who did a bunch of research on contact materials and then made some contact discs from (idr exactly) a special phosphor bronze or something like that. Maybe I can find the CPF thread with the details. He sent me a few of the discs and I soldered a couple into lights, where they worked very well, and I have a few left. I could send you a couple for experimentation if you want.

It’s to solder a spring or a brass button.
On the MP3431 driver the diameter is 6.5mm, I had to decrease it from 11mm because of the larger area needed for 0605 passives vs 0402, but also to place thermal vias under the regulator.
It’s made to fit the small springs from BlueSwordM (BeCu with copper and silver plating), I have some but I’ve yet to measure their actual resistance.

Great Job on this!! Watching closely.

My general hw request was to bring out some extra i/o pads, but in particular, it occurs to me that it would be good to have one with a (say 2x) voltage divider between the pad and an input pin, so you could put +5V on the pad and the pin would see 2.5V (I think it’s not ok to send a 5V input when the cpu itself is powered at 3.6v or whatever).

The feature I want this for is a “strategic flashlight” (as opposed to a tactical flashlight), inspired by an old CPF thread about the concept and a more recent one about power failure lighting. A strategic flashlight is one that is plugged into AC wall power and turns itself on in the event of a power failure, so you can find your way around instead of stumbling in the dark. Those old emergency stairwell lights powered by a SLA battery in a box are a classic example.

The implementation method here is that there are already some Anduril lights with built in USB-powered chargers, done by having a USB charging chip independent of the Anduril driver board. So the idea is to route a wire from the +5V usb power line to this voltage divider input pin. That would allow Anduril to detect whether the USB charger was plugged in and delivering power, even though Anduril itself currently doesn’t understand USB charging.

Anduril would then have a strategic mode where if the USB power is present and then disconnects, the light turns on at a medium (configurable) lumen level, and stays on for say 15 minutes or until power is restored. The 15 minutes (also configurable) lets you manually turn the light on or off without the timeout, and would stop the light from draining itself if it turns on when you’re not around. So you’d leave a light with this setup in your living room when you weren’t using it. If you wanted to use it (unplug it) without having the strategic feature activate, you’d just unplug it while holding the button down.

[Added: Hmm I guess a light with a charger would probably put everything on one board, or anyway the voltage divider could go outside the board, so all that’s really needed here is an input pin, which is good for other things anyway.]

In the long run I hope we can build USB charge control into Anduril itself, allowing getting rid of the separate charging chip, but that is out of scope for now.

Okay that sounds all well and good, but when do ya use all them EDC lights that folks are always talkin ’bout? Are EDCs considered tasticle or stratestical?

I have one. Will send you on thursday. And i’ll meassure FW driver cavity.

Acebeam uses those leaf spring loaded contacts in their tail e-switch lights, I no longer have a TK16 or TK18 to provide pics unfortunately. But their tail e-switch lights are the only ones I have found that have no reliability concerns at all, so I think this is a superior general design concept. Much better than a free floating tube a la FW series or the large coil springs a la Noctigon KR series.

> Okay that sounds all well and good, but when do ya use all them EDC lights that folks are always talkin ’bout? Are EDCs considered tasticle or stratestical?

We all have so many lights that it’s more like we’re having an arms race with ourselves. We have enough lights to elim— I mean _illum_inate everyone on Earth 37 times over ;).

ain’t that the truth—i have to order pants with extra pockets added just to carry all the EDC flashlights and knives that have to be carried.

It seems to me that most flashlights with USB charging have the USB circuit on the driver board, that’s the case on the Anduril flashlights that I saw disassembled (or disassembled myself, IF25, FF E12R), I think that’s how it is in general. So basically this feature would require making a specific driver for one host with USB charging, which is a whole lot of work, at this point adding a solder pad and a voltage divider is trivial.

But assuming a separate USB board, on my driver here there isn’t much space arround the MCU to add a voltage divider (most of the seemingly empty space is needed for the thermal vias and copper pour for thermal dissipation) , unless I move a lot of thing, or use smaller AUX led pads, or remove one. But if the voltage divider can be outside the board then there is space for a small solder pad next to R8, I can add that it’s simple enough.

Yep, I added an edit a few hours after posting, on realizing that the voltage divider could be outside the board. I’m just hoping for enough pads to handle several sensors and/or auxiliary leds, of which the USB power detection could be one. I haven’t looked at any of the boards with USB charging and in case it isn’t clear, I’m an ok programmer but I’m not that clueful about hardware. :wink:

Oh but it would need to be on the front I guess, I would need to squeeze the AUX pads closer together to fit another one.

I made two of the new version, one for a D4v2 and one for a KR1.

I started with the KR1 :

To have sufficient height for the 3mm inductor I used 0.8mm (0.9mm actually) boards with a spacer, as bonus they have 2oz copper weight.

Eurekatronix B35A boards have the holes at 90° so I drilled two new holes for the wires.

B35AM 4000K 9080 installed and at the lowest level (3μA) :

With the Ledil Olga RS

I haven’t yet made an AUX board for it, which is a good things because I planned to have the optic sit on the 0.9mm AUX boards, except after testing I see that raising the optic by 0.9mm degrades the beam quite a lot, a small but obvious egg yolk on the spot and the ghost LED image at the corona that JaredM talked about. I’ll have to make a big hole for the optic in the aux board.

About the driver, I configured it to 3A for the B35AM, it can take more (up to 4A) but I prefer a longer turbo.
That said I’m wondering if the thermal regulation is actually working, I haven’t tested that before because it was only on my test bench with the LED on a heatsink, the temperature reported is also low, I wonder if I messed up something in the code, when modifying the VREF maybe ?

The little flash that I mentioned at turn ON with the MP3431 is still there but greatly reduced with the hardware delay on the HDR FET, I’d say it makes a very short ~0.5mA flash now, hardly problematic.

This is starting to look pretty good ngl :smiley:


Heavy breathing….

This is still your attiny1616 board? Is there a UPDI connector? I will spend some time looking into the GDB interface for UPDI. It will be great if we can interactively debug the flashlight. Then you will be able to look at the reading from the internal temperature sensor from the debugger, for example. Meanwhile, is there already a way to blink the temperature measurement in at1634 Anduril. If you had to port it to the 1616 and aren’t sure of it, it seems straightforward to test it with a heat gun and/or some coolant spray.

Pretty good? That looks incredible. Great work
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