BLF X6/X5 Driver vs. Astrolux S1 A17DD-L FET+1 Driver

Can someone tell me what the differences are? Are they strictly features or are there performance differences? Size differences?

Astrolux S1 A17DD-L FET+1 driver:

Kronos X6/X5 driver:

Performance differences will depend on which driver you get not the FW, quality-wise the yellow PCB drivers from Banggood are not as good as the purple oshpark board drivers from MTN. For maximum performance you can try the red pcb “new updated version” of the FET+1, it has upgraded components and layout to allow even lower resistance.

The bistro FW is heavier and requires the Atiny25 chip vs Atiny13 for the A6 FW.

oops, that link is broken or outdated:
Astrolux S1 A17DD-L FET+1 driver:
~toykeeper/flashlight-firmware/trunk : contents of ToyKeeper/blf-a6/blf-a6.txt at revision 249 (link is external)

Anyone got a link to a side-by-side comparison of the two firmwares, either text or graphic?

The BLF X6 driver is “sold out currently” in Banggood’s shop. Since they usually write “restock at date x” I fear they won’t sell it anymore. Maybe built by Manker?

I believe it’s just a difference in the microcontrollers they use (Attiny13a vs Attiny25) and the firmware (BLF A6 vs Bistro) flashed on to them. The Attiny25 has a a built-in temperature sensor that the Bistro driver uses. The board layout might have changed too but it shouldn’t affect performance.

Someone else posted a link to the firmware used for each one. They show the user interfaces and features of each driver.

Hello guys,
I have one newbie question about A17DD-L FET+1 Driver.

How it works in turbo mode and is it possible to limit the maximum current?
I am going to use it for Convoy C8 with XPL-HI diod and would like to limit the current not to exceed 4A at fully charged battery.
Is there also any schematic electrical drawing of driver?
Thank you.

Drivers using FETs like the BLF A6 driver work kind of like by making an electrical connection directly between the LED and the battery, which is also why FET drivers are sometimes called “direct driver”. This means that the current to the LED will only be limited by the resistances in the driver, and the current will drop gradually as the battery drains. The FET can’t regulate current, but it can be switched on and off super quickly to lower the average current through it so it looks less bright. If you’re looking for a current controlled high mode using a single lithium-ion cell you could check out the Qlite/Nanjg 105C or the Moonlight Special. Sadly an unmodified Qlite can only do around 3A of current. You’ll need to stack the 7135 current regulator chips to get a 4A regulated mode.

You may want to be careful about using that driver with a Convoy C8 host. The BLF X5/X6 driver from the same manufacturer does not make electrical contact with the driver retaining ring of a V3 Convoy C8 and it can’t be soldered to it since the ring is made of aluminum.

I don’t know if there is a schematic for this driver posted somewhere, but you can contact people on this forum who helped design it, like Toykeeper.


Today, I started to learn the driver in my Astrolux S2 (which I have two months …;))

At first I tried to choose one of a group of modes. Flashlight does not want to cooperate, but in the end I chose the mode you want.
Later I wanted to set up a thermal protection. Flashlight included in Turbo mode, waiting for the moment when it gets warm and switched off.

From that moment flashlight turns on only in the moon. Do not react to try to change the mode on a 16-click on anything.

Damaged driver?

Any advice? :wink:

zieloczek100 didn’t get any responses.

I’ve got a wonky one also.
I put an amber emitter in a Kronos X5

It’s been sitting for a while with the tailcap locked out

I just took it up, tightened the tailcap, got the expected blue glow

But the interface gave me 2 levels: a full bright, and a fast strobe.

Hm. So I fiddled with fast clicks
Strange, they came in pairs? BlinkBlink pause BlinkBlink
I treated each pair as a single blick with a flicker, counted 8, and thought I was doing a factory reset.

Started getting three bright ness levels with a flicker just after starting the low level.

Got it switched back and forth a few times between HML and LMH

Got three brightness levels, plus a fast strobe, plus what appears to be a beacon (one flash per second)

I’m rather baffled what it’s trying to do.

I have another X5 light with the stock emitter that’s behaving normally.

Can the ATTINY13A of the BLF A6 A17DD FET+1 driver be replaced with the ATTINY25 without changing the rest of the components? The board layout of the BLF A6 driver appears similar to the BLF X6 X5 driver.

Has anyone ever compared the Mtn version to the Banggood version of the BLF-A6 driver or the X5/X6 driver side-by-side?

It is mentioned over and over again that the Mtn version is better because Richard uses better components, the cap is better quality so there is less temperature effects on timing etc. But is the difference ever actually observed by anyone in the real world, performance wise???

(I have noticed over time that at least the yellow BG BLF-A6 driver is extremely reliable. It does have a strong temperature effect on timing but for the rest it works well in all the various types of builds that I have done over the last two years)

For one, Mtn uses 380 mA 7135 regulator. Newer Banggood BLF A6 uses this:

I was looking for this answer :slight_smile: anybody knows?

and by the way, that’s another point I have always wondering about (I don’t have the mtn version to compare them myself)

The A6 driver seems rock-solid to me. I have four BangGood torches with it, and four that I have modified with the yellow BangGood driver. None of them look pretty, but they do work well.

The off-time capacitor in these works pretty well, there is some slight temperature sensitivity, but nothing to worry about.

The X6 driver was a step too far I think. I also have four torches with this one. It includes a bleed resistor for lighted tailcaps, which if not used just adds extra drain in lower modes, and more importantly messes up the OTC timing, also making it very temperature sensitive.

Once a lighted tailcap is added the whole setup becomes very sensitive to component selection, and temperature.

It can cope with driving a single LED in the XP class, but anything taking more current risks unexpected results, due to upsetting the sensitive MCU.

The off-time capacitor was a rickety idea to enable control via tailcap clicky switch, but works surprisingly well in the A6 driver. Less so in X6.

Furthermore the Attiny 25 of the X6 driver seems much more sensitive to being upset by inductive spikes when driving higher current levels, whereas the Attiny 13 seems pretty immune.

DEL identified the root cause, and made an elegant modification (a small series resistor and relocating the reverse protection diode) which eliminated this problem.

Clever firmware developments (Flashy Mike, Tom E et al.) eliminated the need for the off-time capacitor, and the voltage divider to measure cell voltage.

The first commercial BLF implementation was in the Q8, with e-switch, and it is excellent.

This forms the basis of the Texas Avenger / Lexel designs, which continue to evolve, as do the firmware possibilities.

To summarise: BangGood or otherwise A6 drivers are solid. I can’t speak for MTN versions, they are not economically viable in e.g. UK due to excessive shipping costs.

DIY with Oshpark boards is interesting, but requires a whole new investment in component procurement, assembly equipment, flashing fimware etc. Beyond most.

X6 drivers can be flakey and finicky. They do have a rudimentary thermal step down capability, but it is difficult to get working satisfactorily. Disabled on all of mine. A6 drivers have a timed stepdown from turbo, which can be bumped back up again immediately, relying on the operator to judge just how hot they are prepared to run the torch.

I have both mtn and the atinny25 banggood drivers, and have had both act weird with heat, specially the mtn driver, but that might be due to being used in a nichia triple s2+ vs the banggood driver being used in a single nichia c8

I also have had the X6 board act a little weird in a triple DQG tiny 4th. Thought it was my wiring, so I made up a new board and installed it. Everything seems fine but one little bug. When I ramp to the top (turbo) the light blinks twice and shuts off. Im running NarsilM with a attiny85 on the X6 board. If I double click to turbo, it works fine.
I have both boards the (X6, A6) and have used the attiny85 with NarsilM on both. From what I can tell the boards are identical, except the X6 has the attiny25 and the bleed resistor. All the other components look the same and in the same layout on the board. I have pics of both boards here.

That sounds like the same behaviour as when the cell is first connected, i.e. a power-on reset (double blink etc.) As you ramp up towards turbo the LED is being PWMed, at increasing mark-space ratio, maybe increasing likelihood of inductive spikes (though this isn’t quite logical). Perhaps to the extent that the Attiny85 is sufficiently upset to eventually crash and return safely to power-on reset condition. Maybe the little blink signalling full turbo, rather than PWM spikes, is the culprit ?

In full turbo there is no PWM, hence no inductive spikes (which occur when the LED current turns off during PWM, (or during that little blink when ramping up), perhaps why you can enter turbo directly without a problem.

Just an idea.

DEL’s resistor and diode change in the Q8 driver shields the MCU from the worst of these spikes, and was definitely necessary in the Q8, driving four LEDs hard, even harder with simple mods.

ISTR that when he looked at the A6 driver with an oscilloscope he was surprised that it worked at all, given the spikes visible at the MCU power pins. The old Attiny13 seems to be much less sensitive than the later more complex versions. Somewhere in this archive you can find the traces, and track the development of these mods.

I have heard that the current MTN drivers also have a slightly different modification to “harden” them, but don’t know the details.

Agreed, the current BangGood BLF A6 and X6 drivers are identical layouts, except for adding the pads for the bleeder resistor. There have been small PCB layout changes on the A6 driver since the first version, but the circuit design has not changed. Other than the MCU I haven’t seen any other component changes, but I wouldn’t be surprised if the actual components used will have been supplied from various sources during production. The OTC is quite critical for switch timing, there has been discussion of swapping in more thermally stable versions, dielectric types etc. I have been fortunate that all of mine work quite well, which I can’t say for the X6 drivers.

Tom E and Flashy Mike developed firmware changes that reduced power consumption drastically, such that the MCU can remain supplied by a large decoupler capacitor during tail-switch button presses, long enough for the MCU to detect and time them, i.e. a thermally stable “OTC-less” design. These improvements also result in infinitesimal standby consumption in E-switch implementations such as the Q8 and it’s evolutions.

I think BangGood realised the issue with the (then new) X6 driver when they decided to use the old A6 driver instead in the S41 quad. ISTR that those who tried to substitute it with an X6 driver ran into problems.

Edit: I also see that BangGood chose to use the A6 driver in there recent Atrolux C8, rather than an X6 version. AFAIK they only use the X6 one in their Astrolux versions of the original BLF/Kronos X5/X6 torches.

Hank, could it be that your amber emitter has a much lower Vf (forward voltage) than the original white led ? If so, it would not be suited to using with a FET driver. Typically red, orange, yellow LEDs have much lower Vf than white, green or UV LEDs.

If so it could be being overstressed by e.g. a cell at 4.2V, maybe drawing very high current, which might be upsetting the MCU in the driver.

Maybe try putting back the original LED and see if normal operation resumes ?

I’m just wondering, if replacing the BLF A6 driver in the stock Astrolux C8, with the BLF X6 driver, will the max Turbo mode become different in terms of max brightness levels? (eg. is BLF A6 Turbo mode more powerful than the BLF X6 Turbo mode, assuming the driver is the only change done)? Any idea if there could be any other issues?