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

Series is different for sure, but they are pixel-perfect same size. This might looks like different current/sat specs or simply this driver has lower efficiency with smaller inductor. Bourns has good inductors (https://www.bourns.com/docs/Product-Datasheets/SRP1038A.pdf), I may give a try after ordering driver from KD.
BTW, is KD available? I’ve written some emails but no answer since week…

The 2R2 is a little bit bigger as far as I can tell. I have one of 'em right here. According to my cheap 1/10mm accuracy Aneng caliper its measurements are ≈10.25 × 10.25 × 3.7mm.

It's a bad choice what CDM has done. I may still go for it, but it is less appealing. And remember it lacks reverse polarity protection, so always stick it right. ;-)

Try sending some PM to Kaidomain's boss BanL. Or posting something here: KD (kaidomain): Deals and new products thread

They added a lot of vias. Strange that they would rework an existing design unless they were trying to address a problem.

Are these courses useful for understanding what are you talking about? Of course I’m not paying, money is reserved for more flashlights, LOL.

What about this one? Is it ok?

That is Convoy XHP50 driver Eneen, good of course. Related technical information here: Damian's Testing boost drivers (#3+).

Nailed the best offers for the ∅22mm Manta Ray drivers here and there, btw.

Wow this convoy one is super efficient. It will surely go into my next build despite it’s lacking hi 65% mode. Thx!

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.


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.


: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?