Lexels driver compilation

3A from my calculations

30mm driver got more functionality added and a little bugfix

nice work. Very curious about the new boost drivers.

Skilhunt H03 added


this board is already stocked

24-30mm

new design with added LED resistor to support new 2s 2x2 LED Boards and a little bugfix

this board will be stocked soon

Bad news for the 1 cell boost drivers someone bought all 300 available chips from Mouser and new stock will be delivered in June
no other distributor has avalable stock right now

Hmmm I wonder who that could of been……

Which chips?

Grrrrrrrrr!

The MP3429 is in stock, Lexel, and will work just fine (my driver uses that).

https://www.mouser.com/ProductDetail/Monolithic-Power-Systems-MPS/MP3429GL-P?qs=sGAEpiMZZMtitjHzVIkrqZzDzZChF5ZskUpugSdTH%252bSvPnOIcBEajg%3d%3d

How's your driver coming along?

MP3429 works for XHP35, but for 6V XHP70.2 I want 7A Output

Well it's working fine on my desk (albeit driving XHP50s at 6.5A instead).

It will happen and be done right in any case… and I’ll wait impatiently :zipper_mouth_face:

Lexel, how many amps do you expect the final driver to allow through for the XHP35 and XHP50 then?

Lexel, you had troubles sourcing MP3431. MP3431GL-P is available at mouser. MP3431GL-Z is not. Is -Z needed or did they restock?

They were both out of stock a while back, but yes it just got back in stock. There's no reason to use the more expensive 3431 though unless you are actively using the ILIM pin, as opposed to the cheaper and otherwise identical 3429, which has always been in stock. :)

How about a DD board (boosted to the MAX) for an XHP 70.2 (21mm) FOR A GUN— No UI needed? Possible?

I asked Lexel, waiting to hear back. I built the Sofin 20.8mm C8 kit last week and though about this idea after seeing what Lexel’s TA Bistro board could feed the SST-40 I mounted— (8 amps) :+1: And with Lexel’s tail FET switch (capable of 20 amps), it could manage the on/off.

Could this future driver (that needs about 5 minutes run time on a VERY high drain 18650) be made as you are working on this other boost driver? Could this “magic” driver exist?

Stirring the pot :smiling_imp:

So you'd like a single cell 12A 7.5V boost driver in 21mm form factor with a single mode? :) Your battery will need to supply 30A or so, you'll need more than a just a standard host (contact resistances will be too high), and the thermal dissipation would require a very large (or actively cooled) host as well... which may negate the desire to use a single cell in the first place.

Wait… before I get the kabosh :confounded: — here me out.

This light won’t run MORE than about really, maybe 20 seconds at a time (just long enough to do the Gridwald X-mas light show— Version 1.) :sunglasses:

SO… given the Sofirn can be wired in 16g (with by-passes on rear and direct connect to the top of the front spring), and maybe use a serious MCPCB… CAN this “magic” driver be made???

OK, OK…

Being more realistic… given Lexel’s FET handles 20amps— what would be a DOABLE config for a DD board and (whatever) LED?

Again… NO UI needed and the light would be on a gun that lights up for (usually) enough time to get a shot or two off. So 20 seconds would allow for many shots in a field of pigs and that would be about the time needed for FULL POWER!

Maybe I wait for the final driver here, but thought if there was something in a hot-rodded (20A max) smaller C8 that would work for this specific application (on a gun), that I’d toss the idea out there. I’m SURE there are a few of us hunting types around BLF that would like to have something like this too.

Does it need to be a single cell? It seems to me that if you'd only like 20 seconds to a min at full blast, it'll be easier to use two good quality shorter cells in series to drive the XHP50 or so in direct drive configuration. The resulting driver will be far simpler, easier to make, and you will get a very decent output.

I made a drop-in replacement FET Tailswitch with 1mR ON resistance which requires no battery replacement and works very well for my GXB172 driver builds ^_^. (https://budgetlightforum.com/t/-/50404). The resultant switch is the same size as the regular one so no additional shims or adjustments are needed.

This combined with say two 18350s, a high quality build and an XHP50B should hopefully give the output you want (especially since this time we'll only need to draw about ~12+A from the batteries instead of 20A), or even more for XHP70.

Such a driver should be extremely easy to make too (far more than the switching drivers), and there would be absolutely no reason why you couldn't have all the fun firmware features you want as well ^_^.

I do not need a single cell… and you are on track here. :+1: But to clarify the scope:

Lightweight and C8 (44m) head. Highest output for about 20 seconds possible (but it would be nice if it could survive a longer time interval of service— especially since several short “blasts” of light might occur over a few minutes— thus building up some heat.

I have in the hand:

Sofirn C8S host kit (with 20.8 mm driver area)
XHP-70.2 LED
high drain batteries (20 amp and more).

I do not need any UI, but if I did have it I’d LOVE something like Mode #1 in Bistro (Turbo/off) to be select-able.

But anything can change with my list of gear on hand. I could de-dome (anything) and I’m really thinking that if the driver (at about 21mm can be loaded for OUTPUT— without concern for a UI), that this would be what I am after.

I like your description of a possible config here— can we push it to an XHP70 (with whatever batteries/tail switch then???)

One more post from me before I think we should move this to a new thread, since this is afterall Lexel's thread - apologies for going off topic for a while ><

Typically designing a system with clearly defined constrains is (relatively) easy! The problem comes when people start adding extra requirements and asks and features :).

Otherwise, suppose we have a set of requirements as follows:

  • Use 2S configuration
  • Driver be ~21mm in diameter
  • Designed specifically for driving 6V-type LEDs like XHP50/70/144 in DD FET Mode
  • Work together with low-resistance construction and FET Tailswitch
  • Extra modes and features are nice to have

Then it seems to me like a slightly modified existing DD driver like this (http://www.mtnelectronics.com/index.php?route=product/product&path=67_117&product_id=714) would work just fine and solve your problem. As long as it's configured for 2S operation, it's pretty easy to e.g. optimize the FET for best performance, and fine-tune the thermal regulation to produce a desired operating behavior, and we have the driver you want :).

Finally I do have to point out that I'm really not a huge fan of DD FET drivers since LEDs are not supposed to be driven this way from an EE perspective :p. It's pretty easy to get an LED blown, if for example one day someone comes up with a better battery with maybe slightly different chemistry and higher cell voltage, and very very low internal resistance, and this is coupled together with someone who makes a very low-resistance build. In the case of some LEDs, not too difficult to blow the bond wire. It just so happens that IRL with today's LEDs and builds, it all works out decently. :) LED4Power seems to make some proper high-power current regulated drivers, so that's more like the kind of driver which makes me feel more at ease and how 'FET drivers' should be done.