As requested, 3 XM-L Driver/Emitter module DIY

At the request of more than a few forum members, I've finished up a 3-XML Module that includes the emitters, a constant current driver, and a micro-controller and is designed to mate with the LEDIL CUTE-3 Optics.

I built one up, and it works perfectly - quite awesome, in fact. I've got the production circuit boards on order, and I'll be offering it as a kit for modders and DIYers.

Specs as follows:
35mm Diameter (Same as the CUTE-3 Optics)
Max output: 3.2Amps (up to 5Amps with one resistor change)
Input Voltage: 9-25 Volts
High-Frequency PWM Dimming (NO flicker/beat)
Microcontroller for completely customizable modes (Mode memory available)
- Source code will be freely available once I finish it up
Driver efficiency measured at 96% (at full output) using Calibrated Benchtop Multimeter
All parts rated at minimum 125C Operation, Many rated at 150C
All ceramic X7R Capacitors - No Electrolytic and No Tantalum to fail
0.4MM Thick FR-4 Circuit board with hundreds of thermal via's - Better performance than even the best MCPCBs
Center clearance hole for 6-32 Mounting screw
- Screw this down to your pill and get much better thermal performance than any type of thermal epoxy or tape
3 pass-through holes for wiring
Modes can be changed by removing and then re-applying power (standard tail switch operation) (with or without mode-memory) OR
- Modes can also be changed by a secondary momentary contact input (Power switch and Mode switch combo) OR
- Modes can also be changed by a variable resistance - slider switch, potentiometer, etc OR
- A variable resistance can control the brightness directly in 1024 increments - Essentially infinite adjustment
Extremely Low settings are possible - 3mA (.003A) is the lowest possible drive
Mounting holes for the CUTE-3 Series of TIR Optics
Thermal protection on board - the micro-controller monitors the temperature and can be programmed to shut-down or back-off current
Reverse Voltage Protection.
2D Print and 3D Model of the entire assembly available to help with custom enclosures or torch tubes

At first, I'll be offering these strictly as a kit - you do the soldering yourself. If there's a demand, I will consider selling completed modules built on a production machine line ( FAR better quality than hand soldering ).

** Due to obvious demand for fully assembled modules, and a obvious lack of demand for DIY kits, These will now be available professionally assembled. DIY kits will be available upon request. **

Youtube video of the module in action

Back side of circuit board - Bare Copper/Gold for Excellent thermal conduction to pill:

If you know you're going to want one (or more) of these, PM me and I'll make sure that you get one from the first batch.


That's awesome. Love to hear more.

wow, that looks great!

any low voltage and overtemp protection? Rough ball park on price?

This would be well worth posting on the mtbr DIY lights forum as triple XM-L lights are becoming quite popular there. Plus, there's a guy prototyping a housing that would suit this down to the ground - I'd expect demand to take off a fair bit once that's ready as it'll be the simplest and brightest build around.

Looks and sounds incredible, Pilot! Any idea on expected price?


I've never seen such a nice combo for sale before - what an excellent job with that high efficiency! I love it.

Same as the others - price estimate on 1 kit?

doh! you know, I completely didn't make the connection between this and that mahoosive 4x4 light some crazy guy was building from scratch :) That makes it even more interesting..

Awesome board! Looks like you've incorporated many key features that are highly desirable.

What tint are the XML's?

Will watch this closely....

Price? Tint?

I'll take 5 of whatever you come up with.

Very nicely done !!!

This is awesome news!

What MCU are you using, an AVR?

just some questions from the guy making the 35mm housings (Zemike), here's the link

"Never saw an XM-L on FR4 substrate.

Matt, can you ask several questions on that forum?
1) what is the LED/heatsink temp on full power ?
2) minimum order quantity for a machine assembled module ?"

When you say that we have to do the soldering, exactly how much soldering is that. Also how much will it cost? :p

I'm curious about the machine assembly as well, considering I'm better at soldering, but don't trust myself to do all of that tiny stuff (especially doing the LED).

Glad you like it!

Yes and Yes. I'll have a better idea on price by tomorrow - details then.

Once I have it more finalized, I'll post over on that forum. Thanks for the suggestion!


Thanks! Yeah, that was kind of the plan. The swiss army knife module.

That's the beauty of a "Kit" - They're whatever tint you want them to be!

If I start manufacturing them, I'll likely offer a cool U2 and a Neutral T6.


PIC. Microchip offers the PIC Controllers in higher temp ratings than AVR offers the TINY Series. For instance, the TINY13A in the DFN package is only rated to a max of 85C. The PIC Part I've selected is rated to 150C. Additionally, the PIC is physically smaller. For what they have to do in this application, it's 6 of one to half a dozen of the other anyway.


He'll be plesantly surprised by the performance of an XM-L on FR-4. I promise.

1) Completely 100% dependent on the heat-sink. MCPCB, FR-4, Platinum - doesn't matter what the emitters are mounted on - it's the heat sink that has to dissipate 30 watts.. I can't answer the question, unfortunately.

2) Unsure just yet - I haven't even got the kits shipping yet. Details will be provided if/when I'm prepared to offer a fully assembled module.


For the 'kit' - I mean all of it. You'll get a bare circuit board. Not for the faint of heart, and I don't pretend that it is.

Pricing to be announced soon.. I'm still wrapping up a few details.


A few people wrote to me and asked about mechanical prints and 3d models - I'm assuming to assist in fitting this into an enclosure.

Rather than send it to everyone privately, I'm just going to post a link to the files here.


How low is the low voltage protection? Would this light engine be able to run on 2 x 18650's?

I've had a look at both your drawings and the CUTE-3 datasheet, but nowhere can I see how far the leds are from the center or the board. Will the DRY reflector fit this light engine?