Lexels driver compilation

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.

IF… two batteries can be used on a gun with high recoil (tapped together or whatever is needed) in this config— then I’m interested in this driver! THANKS for that GREAT advice— I will seriously consider it and further research this option- it’s a solution and I THANK YOU for it!!! :+1:

But, the boost drivers here are for the beloved 18650 (one, as far as I understand) and so I’d still LIKE to ALSO continue to look into that route— if we are getting close. Because when out in the field, switching two batteries is more difficult and I’ve read where with guns— it’s just a lot easier to go with one battery. And because I want to stay in the lighter weight (and smaller head) C8— I’m still keen on a driver solution for it that would fulfill my “hunting” needs- all things already discussed… considered.

And yes… sorry for the segway Lexel. But as we were discussing this on PM… here is more info from this “wildcat” head of mine. :beer:

With my Tail FET board you dont need a driver for DD, just a contact board

The MP3429 is rated 30W constant output while the 3431 50W, not sure what exactly is the difference but I would not gamble

Datasheets of both say exactly the same: “Supports 30W Average Power Load and 40W Peak Power Load from 3.3V”.
Though 3431 has an circuit with 50W consumption among examples. Just from 6V, not 3.3V.

Ok the difference is for the MP3431 to have programmable input current limit, which is good to set for flashlight use

Uh wait… hold on?? ?:

Are you (Lexel) saying I can drive the XHP70.2 (with just one 18650) directly?

I thought I needed a boost driver (or board) to get the power up from one battery (or even “turn on” the XHP70.2).

He means that if you just want to drive the LED directly (either 3V LEDs with 1S or 6V LEDs with 2S) with no modes in a Direct Drive way, you can just turn on the LED directly with the tail switch, FET or not.

Sorry, need more coffee…

- so for a single 18650 I can NOT drive an XHP.XX without boosting up to 6V— correct? Isn’t this why the “boost drive” is in the works?

Sorry guys, I am good at ideas and I do not mean to sound nuts. As I don’t (really) understand the chip problem Lexel is having (getting them), I thought IF there were something (he or loneoceans had) already in the hand (no UI needed- but to JUST boost- with chips IN the hand put on a 21mm board)— I could use it for my C8 gun light project (with my XHP70.2 and one high drain 18650) sooner than waiting for the final boost drive (and also act as a beta- I’d be willing to pop a few LEDs for the cause) :smiley:

received very nice Lexel driver, highly recommended

Those look like my NarsilD’s Lexel sold me for use in my C8Fs. I had to grind my retaining ring at about a 35 degree angle on the side contacting the driver to keep it from catching on those chips on the spring side. Dremel is your friend :wink:

Also, that negative LED connect point does NOT ground to the round outer trace (I found out the hard way)- So I ended up running a touch of flux on it to keep my solder from “running” over to the outer ground trace (outer ring). FYI

You can drive 6V LED with 2 18350 1200mAh cells without driver

Or wait for my boost driver which will be not cheap

You know… I want to buy the FIRST (21mm) boost driver you sell Lexel :+1: :beer:

I was just slummin’ around :sunglasses: for something that might have been doable with available parts since I don’t need a UI- because OF your FET tail switch!

I just want RAW POWER from an 18650 in a C8 with an XHP70.2 (is all) :innocent:

Thanks for entertaining my ideas (and educating me) guys!

Not cheap as in $20-30 or as in $30+?
Either way I’m still in for at least one

about 21€

Mouser managed to restock the chips so I bought now 100

Thanks again Loneoceans (and Lexel)… I (again) appreciate your time and patience as you both educated me here on this post.

I’ll try loneocean’s idea: using TWO 18350s in my C8(s) host I am building up next. I’ll run them DD’ed through a board (with no chips/driver “parts” on it- just a bare board AND Lexel’s FET tail switch).

Lexel just said (in a PM to me just now) that I could run a (shaved) XHP50.2 about as good as it’s gonna’ get for throw (given my form factor and it’s limitations with the C8 and using either DD or his driver)— that was also something I wondered about.

So changing gears from the XHP70.2 to the XHP 50.2 in a high tint— so when I shave the dome, it will fall down to about 5k(ish).

I will also still buy one of Lexel’s drivers when he gets them done too— I LOVE my NarsilDs in my C8Fs.

Love the options guys! You BOTH rock :+1: (… best I can do, no little smily with an air guitar available)

I’m so going to wait for boost driver :slight_smile:

But is it long wait lexel?

Lexel can you make a Buck driver for Convoy L2 to drive a dedomed XP-G2 with 6A and with 2S battery config? Or for maximum throw I will be more happy with one of your Osram black flat drivers in my L2 with a black flat led and 1S battery config? How much current a black flat can handle?

Buck drivers:

Input 2S-25V
Output 1-8A as requested

20mm
4 layer for better thermal properties

Black flat draws too much current from a high drain 26650, better to go with a Buck driver 2S on 4.5A

Hmm. I just like the Short L2 :smiley: But I don’t want to use 26350-s. How much is the too much current? I don’t really care about runtime. Just max throw in a compact form. Or the current will be too much for the driver? Or like the XP-G2 the forward voltage going too high? Sorry for lot question but Soon I will be ordering from you some boards or complete drivers. :money_mouth_face: