Led4power.com : LD-4 CC linear drivers, ILC-0/1 illuminated tailcaps, optics, MOSX, copper DTP MCPCBs...


Added new copper DTP boards:


Price for 16mm DTP pcbs:

1pc - 1,07€

50pcs - 0.95€

100pcs - 0.8€

Price for 20mm DTP pcbs:

1pc - 1,17€

50pcs - 1.0€

100pcs - 0.9€

Price for 20mm 3XP and 4XP DTP pcbs:

1pc - 1,37€

50pcs - 1,2€

100pcs - 1.1€

If you want to buy 50+pcs, please contact me so I can give you coupon code, currently page doesn't automatically calculate discount.

Gold plated phosphor bronze spring 12x9x1mm 0,87-0,97€

Also added new ILC-0 listing with fixed default currents at 1€ lower price:

ILC-0 default currents 4,97€

Also, one note related to LD-x4 drivers listings: you can now choose do you want 1mA bleeding or not. If you don't plan to install illuminated tailcaps, it's

better to not have bleeder for two reasons: lower active state driver consumption (1.6mA vs 2.6mA), and 1mA lower sleep current (~40uA vs. ~1mA).

ILC-0 illuminated tailcap with CC and LVP: 5,97€ link

LD-x4 driver: 9.97€ link

Luxeon V: link

L4P 4040 DTP 16mm for Luxeon V: link

LD-A4 thermal enhancement kit for S2+: link

Hello BLF-ers,

last few months I've worked on some new products, so I decided it's time to open a small workshop,to pay taxes to the government:), and open a small web-shop for easier order handling - led4power.com

For now there are only few (but mighty) products, plan is to make some more over time.

Full specs, datasheets etc. are available on web page, so I will just shortly introduce new products:

LD-x4 17mm constant current LED driver

LD-A4/B4 2-12A constant current („PWM-less“) LED drivers are next generation of LD driver series. Based on completely re-designed hardware and improved firmware, these drivers are optimized for single-cell (4.2V) flashlights, and offer some new features compared to LD-3, like hardware (real) direct drive mode option, 1-wire temperature sensor support, integrated moonlight with 3 levels (2.5mA, 5.0mA, 7.5mA) adjustable via user interface, and low current bleeding support for illuminated tailcap modules like ILC-1. Typical bleeding current is just 1mA, which is 5-10 times lower than conventional resistor bleeding. This enables significantly longer run times on moonlight modes.

LD-A4 is standard type of linear driver with all components on PCB, designed for power dissipation 2W -6W@60C. Recommended applications are single Li-ion cell LED flashlights with single LED.

LD-B4 is designed to work with external power MOSFET (source of heat) for much higher power dissipation – up to 15W@60C, which is more than enough for any triple or quad LED setup. “MOSLED” high performance metal core PCBs have space for MOSFET and NTC sensor, which makes triple or quad LED builds fast and easy, and more important – reliable because of real constant current driving/limiting.

Hardware features:
  • True PWM-less constant current (all modes)
  • Available as 3, 6, 9 and 12Amps version – 2-12Amps possible by adjusting current in UI
  • Completely silent – no acoustical or EMI noise („whining“)
  • Longer run-times on lower modes compared to PWM drivers
  • Higher overall lm/W efficiency on lower modes compared to PWM drivers
  • Lower losses in springs, wires, switch compared to PWM drivers
  • Very low internal resistance comparable to best DD drivers
  • Hardware DD mode option on high mode without current limit
  • Calibrated internal voltage reference and temp. sensor
  • Dual over-temperature protection (internal, and external [NTC] sensor) – single wire NTC connection
  • Integrated moonlight with UI selectable 2.5mA – 7.5mA current
  • Low sleep current
  • Improved Off-time mode memory circuit
  • Low current (1mA) bleeding support for illuminated tailcaps
  • Single-sided PCB with large (9mm) spring pad on bottom side
  • 4-layer gold plated PCB
  • Lead free

ILC-1 illuminated tailcap module/drop-in

ILC-1 illuminated tailcap modules are devices with integrated reverse clicky switch and tailcap LED illumination with control electronics in one, easy to use case. Depending on LEDs current and color, flashlights equipped with ILC-1 module can be visible not just in dark, but even under normal light conditions, which makes them easy to find and differentiate. LED tailcap illumination is usually much brighter compared to tritium vials, costs less and colors are more saturated.

With ILC-1 and 8 LED colors available, every light looks exotic!

ILC-1 is primarily designed for small Convoy flashlight hosts with 16x8mm silicone tailcap buttons, in combination with LD-x4 driver series.

Ultra-low power 2-channel circuitry drives 8 LEDs with constant current, which ensures constant tailcap brightness, completely independent on battery voltage, LED’s forward voltage/color, bleeder resistance, and temperature variations. LEDs current can be easily set up to 600uA with two 0603 resistors. All LEDs are closely matched by their Vf, to ensure equal current distribution through each LED.

Also, very important feature is built-in 2-step low voltage protection which shuts down LEDs when battery voltage drops below 3.0V and protects battery from over-discharge.

  • 8x LED (2×4) for maximum light uniformity
  • Constant current LED drive (2 separate channels) – stable tailcap brightness over voltage and temperature range
  • Closely matched LEDs by their Vf
  • Reverse polarity protection
  • Low voltage protection
  • Easy constant current set via single 0603 resistor on top PCB (per channel)
  • 8 basic LED colors available
  • Integrated OMTEN 1288 switch
  • 10mm diameter spring pad
  • Gold plated PCBs
  • Translucent tailcap button and spring included
  • Lead free
LED Color options:
  • Red
  • Green
  • Blue
  • Orange
  • Cool white
  • Warm white/Gold
  • Purple/pink
  • Ice blue/aqua
Electrical characteristics:
  • Input voltage: 2.8V-4.35V
  • Switch type: OMTEN 1288, reverse clicky switch
  • Switch rated current: 3A* ( tested up to 15A )
  • Active state (operating) current: 4uA typ.
  • Sleep/off current: 1.5uA typ.
  • Step 1 LVP (reducing current) threshold: 3.0V+350xItotal
  • Step 2 LVP (shutdown) threshold: 3.0V typ.
  • Number of constant current outputs/channels: 2
  • Max. recommended current: 600uA total (channel1 + channel2)
  • Operating temperature: -20C – +60C


These high performance metal core PCBs except for LEDs, also have footprints for external power MOSFET and NTC temperature sensor on single board, which makes them ideal for very high power multi-LED builds with LD-B4 driver. MOSFET on such MCPCB has best possible thermal contact with flashlight body, so it can dissipate a lot of power without overheating, and connecting NTC temp. sensor to driver is very easy. MOSLED PCBs are made from aluminum with high performance insulation layer, and tests show they perform significantly better than copper NON-DTP boards, and they are close to DTP copper MCPCBs performance. At 3A per LED, difference in brightness compared to DTP copper PCB is only 2,3% (copper NON-DTP gives 3,8% lower output).

MOSLED MCPCBs are over 3 times lighter compared to copper DTP and NON-DTP boards, which makes them especially suitable for headlamps and EDC lights.

3XP and 4XP MOSLED MCPCB are compatible with Carclo 105xx and 106xx optics series.

With MOSLED MCPCB and LD-B4 triple or quad LED builds are fast and easy, and more important – reliable because of real constant current driving/limiting.

Note: due to high thermal conductivity on whole board area, soldering wires is more challenging; one simple solution is to preheat PCB with hot air or with soldering iron (by holding iron tip on + or – pad) and then solder wires. During soldering, PCB must be thermally insulated(piece of thick paper is good enough) from any thermally conductive objects.

  • compatible with 3535 XP footprint LEDs (parallel connection)
  • compatible with Carclo 105xx / 106xx optics
  • compatible with LD-B4 driver
  • High performance insulation layer – very low thermal resistance
  • Aluminum core – 3.3 times lighter compared to copper PCBs (1.25grams)
  • Power MOSFET footprint, 0402 NTC sensor fooprint on board (1-wire NTC connection support)
  • Gold plated contacts
  • Milled edge – flat bottom side
  • Diameter: 20.0±0.15mm
  • Thickness: 1.5mm
  • Center hole diameter: 3.8mm

That's it for now, please feel free to ask any questions, and please report if you notice any problems with web related stuff.



That MCPCB is interesting.
However, have you thought about making a boost driver? More costly and less hot-roddy, but better otherwise.

Some cool new products there, you have been busy!
Good luck with the webstore!

(at the end of the first alinea of the LD-x4 description: ‘lower’ should be ‘longer’ ) edit: what Ronin said :smiley:

So this driver disabled the bleeder resistor when on, so the moonlight can run longer?

and you moved the FET to the star for proper cooling

Switch rated current only good for 3 amps? I foresee a few cooked switches…


Linear CC drivers will be always best overall choice for small 1-cell lights in 90% of cases, simply because they are very small, cheaper, and have high output power (if you need it). Also average efficiency (from full to almost empty cell) is not that bad at all, for example avg. efficiency with modern low Vf led (let's say Vf=3.0V) is 1/2*(3/4.2+3/3)=85,7% , that's comparable to most switching drivers, and with these new low Vf LEDs you also have full regulation basically until battery is nearly empty.

As you can see, two main advantages of boost drivers(efficiency and regulation) are not that much better after all with today's low Vf LEDs - in real world you got slightly better efficiency, but that depends a lot on current,so it may be actually worse vs. linear at higher currents; and stable currents/brightness during battery discharge, but with all new very low Vf emiters linear drivers can also have full regulation 80-100% of run-time.

So in my book, boost driver disadvantages - higher cost, bulkiness, and lower max. output power for size still outweighs good sides.


Error corrected, thanks!


Bleeding technique on LD-x4 is more complex compared to traditional resistor bleeding, result is 5-10 lower bleeding current (it's like having 4kOhm bleeder without loosing functionality).

LD-A4 has MOSFET on it's own PCB, LD-B4 is used for external MOSFET (very high power dissipation possible).


Switch in ILC-1 module is 1288 OMTEN switch used is all Convoy lights (as matter of fact, I bought them directly from Simon, because there are some fakes), I believe djozz tested these, and they were fine for up to 15A, and many BLF members use them at 6-12A in Convoy hosts.

I put 3A, because I don't know how reliable are those at higher currents (just like LED manufactures have max. current rating for their LEDs significantly lower than what we all use).

Ooh, thanks for clarifying :student:

For those who don't like to read all specs, here is a very short description of LD-4 and ILC-1:

LD-x4 drivers

New version of CC linear driver, several differences compared to LD-3 driver:

  • single cell only (for now)
  • ability to choose moonlight current via UI (2.5, 5.0, 7.5mA) (no need to solder any additional parts)
  • 1-wire NTC support - only one wire connection is needed for proper ext. OTP function, which simplifies build (especially with MOSLED MCPCBs)
  • Illuminated tailcap support with only 1mA bleeding - LD-x4 mode memory is not affected by adding illuminated tailcap, no need for annoying resistor-tailcap-LED matching
  • "Hardware" Direct Drive mode on high option - LD-x4 has real DD mode on high,and it's identical to DD drivers, so there is no current limit in that mode (LD-3 had some current limits)
  • Single side PCB with big spring pad and slighlty bigger LED wire holes - easy placement of big springs and spring bypass, easier wire soldering
  • Some functions are changed in UI (removed bike strobe, added 2x-3x click shortcut to high mode)
  • New, more powerful low-power microcontroller
  • LD-B4 variant doesn't have MOSFET on driver PCB, it has two contacts(GATE-mandatory, and optional for moonlight) for external MOSFET connection - MOSFET on MCPCB can dissipate a lot more heat than MOSFET on driver's PCB, simply because thermal resistance is much lower -one of major complaint about LD-3 was limited power dissipation; with LD-B4 that problem is solved, so triple and quad builds are now very easy, and with new generation of LEDs with low Vf, constant current regulation becomes a basic necessity, not an extra feature
  • Lead-free

ILC-1 illuminated tailcap module/drop-in

  • New product, which makes illuminated tailcap build very fast and easy, ILC-1 is a "plug&play" solution, works with LD-x4 drivers, but it will also work with any driver with installed 300-500Ohm bleeder (effects on mode memory for other drivers are same as classical ill. tailcap builds)
  • ILC-1 is designed for Convoy hosts, if there is enough interest my plan is to make version for EE X6 lights.
  • ILC-1 has integrated genuine OMTEN 1288 switch
  • ILC-1 has 8 LEDs and 2 channels, each channel drives 4 LEDs in parallel, each channel is real constant current souce, so LEDs are driven with constant current which gives constant brightness,not affected by battery voltage and temperature variations
  • Current on each channel can be set via single 0603 resistor
  • ILC-1 has LVP, which means it will shut down tailcap LEDs when battery voltage drops<3V, and this way protect battery from over-discharge

  1. In high outputs, linear is indeed close to boost. In lower ones, when you have 2.6-2.7 Vf, efficiency drops to 77.1. With a 95 efficient boost driver, linear loses nearly 20% runtime.
  2. When thermals are the limit, higher efficiency = higher output. So linear allows higher peak output, but can sustain (slightly) lower.
  3. Some just want to use XHP leds with a singe battery.

On another topic, does the larger MCU have enough flash to fit e-switch software?

Wow very nice work on these new drivers and web site Neven! :+1:

Just made an order, question, one of the options for the LD-B4 was 3 signal wires?


Great looking stuff here! Love the ability to do full cc regulation or have dd in the same package, that’s great! I ordered a “B” variant with matching mcpcb to play with.

Curious why you went with aluminum mcpcb though. I see your comments above, only 3% difference, etc, is that all? Maybe its not very logical, but aluminum mcpcb’s just…aren’t thought very highly of around here most of the time. The weight can’t really be a deciding factor, mcpcb’s are small. Is it the cost? You’re selling a ~$17 driver. I think those of us buying those would gladly pay the extra couple of dollars for a copper mcpcb. I trust you though, so I ordered it anyway :slight_smile:

Also curious about the LVP on the lighted tailcap. That’s a big improvement to those circuits. Care to share how its done? :slight_smile:

Placed my order. Need to come up with a host now :person_facepalming:

Yes,on lower currents boost would be more efficient, problem with flashlights is that you usually have several modes with currents from few mA to 10A, so it all depends which modes do you use more often. On very low currents (moonlight) linear is again more efficient because of lower supply current, on low-mid modes boost would be more efficient, on high modes they have similar avg. efficiency, but linear can give several times higher output current, this is main reason why linear is optimal for people who want lights with light output from sub-lumen to several thousands of lumens in a small package.

XHP35 is a nice LED, of course when you don't have a choice, you must use boost driver.

Larger MCU has plenty of memory, e-switch firmware can definitely fit, I only have to write it:)



LD-A4 has one signal wire "T"(temp,optional,white color) for NTC resistor connection.

LD-B4 has 3 signal wires - "G"(Gate,mandatory,yellow color), "M"(moonlight,optional-if you want moonlight mode to work properly,red color), and "T"(temp,optional,white color) for NTC resistor connection.

I will add those explanations to web also.


Thanks, while DD still was very desirable feature at the time of LD-x4 design, these days all high Vf emitters XM-L2, XP-L,XP-G2 are almost outdated and all new emitter have very low Vf, so DD is almost useless, LEDs draw too much current with DD, so I recommend DD option only for XM-L2, XP-L,XP-G2 emitters.

About MCPCBs, well after doing some calculations and practical experiments, my conclusion is that NON-DTP copper MCPCB is total nonsense, probably pushed by Chinese simply because profit is higher, with NON-DTP boards bottleneck is always insulator, and influence of core material is negligible, power densities are just not high enough to see any difference. It's much better decision to invest in best possible insulator which has great impact on board performance, than investing in copper core which has negligible impact. As you can see from graph on my web, MOSLED MCPCB is aluminum core PCB,but with very good insulator, so it performs almost twice better compared to copper NON-DTP PCB, and those NON-DTP copper PCBs perform much better than generic ALU MCPCBs, but not because of copper, but because they use higher performance insulator. DTP copper makes sense of course, but I can't use DTP because MOSFET drain must be insulated from bottom, and insulation on DTP pcbs is very thick,and has very low thermal conductivity, which is good for easy wire soldering, but bad if you want to cool component on top non-DTP layer.

About LVP: LVP is made with comparator + volt. reference, so it shuts down circuitry when input voltage drops below reference value.

Your linear drivers are the best in the business bar none IMHO, great work! I think I will be picking up a few to try out.

As for the boost driver discussion, I mainly like them for being able to run XHP series from a single cell, and being able to do 3S and 4S multi-emitter lights from single cells, all while still being able to use the entire battery discharge range with full power output.

The benefit to running multi-emitter lights in series configuration is that it allows mixing of emitters freely, so we can run a triple with a 219B, 219C, and XPG2 if we want, and they will all see the same current.

I have a schematic posted for an MP3431 based boost driver, the IC isn’t available yet, but when it becomes available it will support up to a 21A input current on paper. What we can realistically get out of a flashlight sized driver package will remain to be seen. If you want to use the design though feel free to PM me, I have no problems with someone producing the driver and won’t ask for any money from small business like yours.

I totally agree that the optimal choice depends heavily on the use.
I don’t think there are many cases (if any) where linear would provide “several times higher output”. OK, we’re talking about 17 mm drivers, so these are mostly used in moderately sized lights. Let’s say a single high-current 18650 battery.
GXB17 does 6V 3A output, which is enough for 2500 emitter lm with a single emitter (XHP70.2) and 3000 lm in a quad (XHP35, slightly better than XP-L). LD4 with a single emitter can do c.a. 1800 (XP-L2) and with a quad - 3750 (XP-L). LD3 was more powerful, would do 4500 with a quad, but the same 1800 with a singe emitter. Linear+FET are even more powerful than this, though I’m yet to see 6000 emitter lm in such setup. If you went with a 7-led setup, Linear + FET would certainly double the GXB17 output, though then you (typically) don’t have to restrict yourself to 17 mm drivers. Also, RMM said that he was working on a boost driver that would pull 10 A from battery, so GXB17 might be beaten when he’s ready.

I asked if you thought about it because you make by far the best linear drivers out there (at least hardware-wise; Narsil seems to have better UI). GXB17 is already very good on paper and I thought that if you made a boost driver, you could create something even better.

ADDED: BTW, I like XHP50.2 more than XHP35. I wish there was XHP35.2….

Aluminum DTP boards proofed to be close to copper DTP

I sanded down a cheap star which had like 0.15mm insulator

If there is an insulator like Kapton tape the layer is only like 10um thick, so the heat transfer should be not too far behind DTP aluminum boards

For not to hard running triples the star is OK and relatively cheap

Could you supply us with the datasheet of the FET you use?

New products look great. Some nice innovation with the FET on the MCPCB. This idea has been discussed here before, but it’s very good to see it actually done in a new product design.

Led4power, agree about the benefits of a powerful linear driver. I think some people think linear drivers must be very inefficient because they get hot, but as you pointed out they are really no less efficient than good/typical boost/buck drivers. Of course, as discussed above, boost drivers do have benefits depending on how the light is used.

Regarding new vs old generation Cree LEDs: the new ones can be more efficient and powerful, but they don’t have as high luminance and so don’t throw as well as the old gen crees. So XPL, XML2, and XPG2 are still very relevant for lots of people, and so the option to direct drive is nice to have.

Those are really interesting products! Congrats


I have nothing against boost drivers, they are good for situations like you described, they are just not high on my priority list because you can achieve similar results with proper combination of driver/battery/LEDs, at least when it comes to brightness/throw. I want to finish linear drivers design first (and there is still some work to do, especially multicell support and e-switch support),since they will be always an useful option in many cases.


XHP70(2) is a quite big LED, so it would give a very floody beam in most of small hosts (which are 1-cell in 95% of cases), so few hundred extra lumens more compared to much smaller XP-L2 LEDs is basically not visible, except indoors. XHP35 in quad are probably little better,but still they are bigger LEDs compared to already floody XP-L HIs, and 2x more expensive. The point is, you can get high lumen output with boost drivers, but at cost of wider beam and higher price, in some cases it's acceptable, in others not. LD-3 is more powerful than LD-4,how? They can do both 12A (actually,they can go 25+A, current is not a problem,problems above 12A are switch,springs,battery and total generated heat itself). Linear+FET = LD-3 LD-4, they both have DD option oh high, LD-4 has "real" hardware DD without any current limit.

To answer to your last paragraph, please see my answer to Jensen567, it's identical.


Mosfet is PSMN-2R4

Does the LD3 FET fit on the new MOSLED board?