LD-40! (17mm Buck driver, 3-16.8v!)

GRRRRRRRR saw LD 44 in the recent posts and thought yeah new Fenix light, ah well encourages me to pay more attention, Naw CBA.

LOL, is that better?

Yes thats better for those of us (me) that fail to pay attention to the section the post is in due to there excitement over the prospect of a new Fenix light.

Thank You

Awaiting the results of modding this driver I ordered two, hoping that they can be made to deliver 4A current. (and still battling with Fasttech's Bonnie to get them to deliver the Uniquefire UF-1405 instead of the wrongly delivered UF-1406 )

Hopefully the stock current is so low only to help out with making it usable with only 1 cell (see the Nichia discussion a few posts up), that inductor looks far too beefy for such low current. If the other parts of the driver are truly limited to not much over 2A I think they would have used a 2A inductor, which would be a lot smaller than what's on there.

Looking forward to an update on these.

same here ,might be good option for car applications as well.

Nothing more than pictures so far...

I ordered several of them on 9/15, and it took until today (9/20) for them to show up as “Acceptance” at USPS.com :(…

http://intl-outdoor.com/ld4b-24a-17mm-buck-driver-3v16v-p-817.html

IOS calls it an LD-4B

Also the output currents are different.

Max is up to 2.4A

There are also mode groups…

Maybe that’s what the solder pads on the battery side are for, i.e., select either 1-mode, or 3-mode?

IOS- always starts in high.

CNQG- always starts in low.

Comfy, do you know if this could be coerced into a P60?

I have one. It is too high to fit in the standard P60 brass pill.

Thanks syracuse.

Magnetics, Inc. makes a special line of thin toroid cores. I wonder if replacing the stock inductor with one of those would suffice for P60 compatibility. Magnetics’ documentation is pretty comprehensive; if one is really inclined to try this they may just find one that will support the requisite flux without saturating.

Have you started testing it yet? And if so, do you have any data (Iin, Vin vs. Iemitter,Vemitter, etc.)?

Sorry, I have not done anything yet - very busy with my children and my work…
I’m planning to make some P60 copper pills to use with this driver and the BLF17DD.

!!

compared with LD33.

Thanks for the links, but when I click on the pics, it’s taking me to a page with bunch of links, rather than displaying the original pics.

I guess that:

- 8205S is a dual-channel N-channel MOSFET (6A/20V, Rds(on) 28mA, STT8205S_11 datasheet(1/4 Pages) SECOS | N-Channel Enhancement Mode Power MOSFET)

- 3912 is some kind of (schottky?, zener?) diode

Thanks for the pics comfychair.

Parts info:

  • The popular QX9920 buck controller as we’ve seen on a lot of controllers. Marked LEDA 1328.
  • Two tiny 8205S N-Channel FETs (with a ridiculous pinout, is that normal for the SOT-26-6 footprint?). This is probably the same FET configuration we see in the “new DRY” driver, the lightmalls driver, and probably others. Note that these FETs are not in parallel, the capacity cannot be added together.
  • IC marked 00VM - probably the modes chip. Also that’s probably a batch code or whatever, not the name of the IC.
  • R100 sense resistor
  • Diode marked 39 12 - I assume that this is a 3A diode.
  • As usual there is a zener present to support the QX9920, it’s next to the IC marked 00VM.

As pointed out by the IOS listing, this driver has no low voltage protection. Running 3s into an XM-L will let you pull the cells down to a very low voltage with a low current draw from the cells. I suspect that some protection circuits may not trip. (I’m a pessimist.)

This driver seems very similar to the Lightmalls one I linked above which ohaya has put a bunch of work into (component pics on second page).