Buck and Boost Drivers, Testing, Modding, and Discussion (Pic Heavy)

There’s a new Convoy 22mm driver, XHP35 at 2.3 amps. Same controller as Loneoceans GXB172 so it should be easily configureable for 6 amp 6V, or just get a 12v mcpcb and resistor mod it.

https://www.aliexpress.com/item/4000046041955.html?spm=2114.12010612.8148356.9.27654e0dKFiR1y

hi is the driver the same in all of Malkoff drop-in’s?.

I think Nichia M61 219B V3 single mode is a Buck driver right? - is this a new or an old buck updated driver or was there something else before this?. any reason for Malkoff not to get with the times, and update? -

I have read about malkoff using old tech electronics which could do with some updating. not sure.

I know the Malkoff is a reliable light, but is the driver reliable in 2019 too?.

kind thanks.

I’ve asked KD recently about the change - they didn’t change the picture so I charged them with not maching product description. They’ve replied this change was necessary to implement thermal management option. They claim it has a temperature step down now.

Can anybody confirm? Deny?

Edit: just to be honest: as I understood KD explanation - the inductor change was necessary to maintain the same price after implementing temperature control. So in my understanding KD traded better inductor for temperature control.

So, downgrading the inductor was necessary to implement thermal management?

What a lie.

The last change was not the inductor, it was the board layout. Perhaps some new resistors, as you can see in the comparison-picture.
The Inductor was an earlyer change.

Hey, so i’m new here, my first post in fact. I’m just wondering if this driver board (KX70) has a user manual, spec sheet, or if there is any documentation or explanation anywhere as far as using it. I am hoping the driver has some user configurable settings, like modes, power levels, voltage output, and such. But I can’t find anything anywhere.

Does anyone know if this driver has a menu system? Does anyone know how it works? Does anyone have the manual or a web link?

Thank you!

Hi everyone,

I am looking for a driver to (re)mod an older 2S 18650 flashlight.
Now it runs with a 6V XHP50.2 and an FX-17A buck driver. But I want to have more modes and 100% output current stability through the entire battery discharge interval. And I hate the mode group change indication blinking of the FX17A in low mode. :smiley:

So the big idea is to replace the 6V XHP50.2 to a 3V version, and install a higher output buck driver. P4000 would be an instant solution but the mode spacing sucks ( to me ).

Second idea is to install this driver: https://www.aliexpress.com/item/32968062007.html?spm=a2g0o.productlist.0.0.758a5f1d2tM0J6&algo_pvid=fbafeace-ff75-4001-b873-ceedbc92b81d&algo_expid=fbafeace-ff75-4001-b873-ceedbc92b81d-13&btsid=ef918fd3-c8cb-42a1-a2df-6d1bad2bd34c&ws_ab_test=searchweb0_0,searchweb201602_7,searchweb201603_55

Runs form 2s/3s and supplies 4800mA max - but it is a 6V output driver. My knowledge of DC-DC converters says that basically possible to drive a 3V led from a 6V driver since the current is controlled. Of course the output ripple, the overall efficiency, etc. can/will change. But there can be other restrictions or protection functions of the circuit I don’t know about.
What do You think? Do You have IRL experiences of such builds? Or maybe any experiences with this triver?
[ Of course I asked the seller. Of course said that apocalypse will occurs if I try it. :smiley: )

Thank You in advance!

You mean since the output voltage is precisely tuned to match the specified current flow, doesn't it?

Well, my answer is also yes, it should work well, but you may want to wait for some real electronics expert to chime in (just sent someone O:) a request).

I accidentally fitted a 3v XHP50.2 to a host with a 6v driver, I didnt even notice… it wasn’t till i went looking for the 3v emitter i realised my error… its still in there and it still works :person_facepalming:

Basically, but not exactly, yes. :smiley:
I mean that LED drivers ( well, correctly built led drivers ) are controlled by/for output current ( through sense resistor ). Actual voltage is only a consequence.
But there can be some safety functions on output like overvoltage protection ( not important for buck drivers ) or LED fault protection ( undervoltage / shortcut protection - not important again for buck drivers ).
Or maybe the current sense resistor is a high side type and the feedback pin of the controller can only work on a higher voltage interval.

Thanks!

:smiley: :+1:
Could You tell me which driver was that?

What ever they use in These I removed 2 of the 4 stack of resistors to drop the output down to about 4amps, changed the lens for one with a much shorter FL then mistakenly fitted the 3v 50.2

There are not many information available about the technical details of the lamp. :confounded:
Was there an old style toroid inductor driver in it, or a high frequency with a shielded SMD one?

It is toroid type, Its a pretty rubbish driver , just low & high with strobe. I just bought one to see what was actually in it…

I did see a 6v driver that looked sorta ok 4.5A

I only dropped the current to 4A in the other one because its thermal path is so terrible

The other one you Posted doesn’t look to bad either

There is not a huge selection sadly, Djozz posted a good test on the emitter XHP50.2 Lots of potential if you can actually power it right up

Yeah, toroid drivers generally runs on low frequency resulting terrible flickering. I experienced that.
The 4.5A You linked is a 2 group driver, like the one I want to replace. This one has higher current, though. But in the lowest mode it always blinks 1 time as waiting for group change command. Annoying.

I think I will make a try with the Manta Ray driver. In the worst case I flushed 9 bucks. :partying_face:

[quote=Lacerta]

Let me know how it goes, if they are any good i may grab one too.

You bought this terrible ignominy?

And you're saying I removed 2 of the 4 stack of resistors to drop the output down to about 4amps, are you serious? Because if so, the driver must be a big buck driver. 8 amps in a 2S buck driver is nice, could you please share photos of it? No rush, of course, but take the oportunity to reset the sense resistors (lower it even further LoL), a 3V XHP50 can take that. And we will see if the driver can take the heat. ;-)

[quote=Barkuti]

I know i am ashamed to admit it, I have tried to wash away the dirty feeling but it still lingers … it was only 12 bucks….

I expected it to be terrible and it was worse. the beam pattern from its Fake Xhp70 will summon Bill gates if you shine it in the sky

I will strip it an get some current readings for you when i get a chance

Can't be that bad, or does it?

No need to feel ashamed or guilty for anything, its our creation so better learn from the experience.

I've taken a look at the video from the ad, looks like its long-necked so long stock focal lenght. Since you changed its lens now it must over-focus, doesn't it?

If the driver is good and the emitter is well heatsinked, it may be a good host after all.

But does it output 50K lumens?

Sure!