Test/Review of LD-33 Triple XM-L 2.6A 9-17V Circuit board

LD-33 Triple XM-L 2.6A 9-17V Circuit board





Driver is from Intl-outdoor.com

Official specifications:

  • Suitable for 3 or 4*18650 or 26650 batteries
  • Suitable for 3 LEDs in series
  • Step-Down (Buck) driver
  • Input voltage: 9-17V
  • Output Current and Modes: High (2.5-2.6A) - Medium (700mA) - Low (100mA), High (2.5-2.6A) - Medium (700mA) - Low (100mA) - Strobe - SOS
  • Constant current circuit
  • Memory function
  • This driver does not use PWM
  • PCB Diameter: 23.5mm
  • PCB thickness: 2mm
  • Total height: 15mm
  • Cathode (Negative) pad diameter: 6.5mm
  • Components height on the cathode side: 2.5mm
  • Components height on the inductor coil side: 10mm
  • Gold plated contacts
  • Low voltage protection: Light will slowly flash at 9V (3 batteries) and 12V (4 batteries)
  • Tinned leads



You can change between the set of modes by turning on the flashlight on low mode for about 3 seconds,the light will flash once, then quickly turn off the flashlight and then turn it on.



Measurements

Tested with: 3 Cree XM-L2 in series.
Diameter 24mm
Max. height: 14.7m
In first mode set the driver has: High, medium, low, strobe, sos
In second mode set the driver has: High, medium, low
The mode set selection is done from high mode.
The driver has memory, the actual mode is stored when the light is off for a short time.
A short off/on will select next mode.
Driver is buck only.
Strobe is 15hz


High



With four batteries the driver keeps full output down to about 14.5 volt, then the output drops and at 11.7 volt the low battery warning starts.
The low battery warning will drain the batteries down to 7.5 volt, before it turns off.






With 3 batteries, the driver will first drop in power at 10V and start warning flashing at 9 volt.
As with 4 batteries the low battery warning will drain the batteries down to 7.5 volt, before it turns off.







There is a slight difference in the buck frequency, depending on number of batteries.




The low voltage warning is not a fast flashing, but a slow (2 sec cycle time) ramping up and down.



Medium



On medium the light does not step down, but goes directly to warning flashes.






This works the same way with 3 batteries.









Low




In low mode the efficiency goes down, due to the drivers own power consuption.
Also note that warning flashes increases the current consumption.






In low mode the 3 battery curve does not start at 13V, but at 12.8V. There is a reason for this, the 3/4 battery threshold is just below 12V in low mode.









Strobe




With strobe the lower battery voltage has largest output.
The strobe frequency is 15 Hz.



Sos




The sos mode is nearly unaffected by the battery voltage.


Conclusion

This driver does a good job of driving 3 leds from 3 or 4 LiIon batteries with good efficiency, but I am not impressed with the low voltage warning, it activates at to low a voltage and it does not shut down the light.
This means it is important to use protected batteries (Always a good idea with batteries in series).



Notes

How do I test a led driver
List of all tested drivers

Awesome detailed review, thanks!

I think there was a brief discussion about the cheapest source of these drivers?

There is something wrong with this review. Intl-outdoor is still selling it.. :D (some of you guys will understand this comment :p )

Great driver! Great review, thanks HKJ, much appreciated!

They're actively trying to kill us with that low voltage thing, aren't they? Interesting.

Now do the LD-36. :) I really like it, but it's big... I'm still looking for a place to use it. Stepless dimming, no blinkies. But it's not a true buck driver, it won't run a MTG2 with any number of cells. But, it does 4.8A into a XML2, and has an easily accessible sense resistor and can be pushed much farther. Electronic/momentary switch, short press for on/off, long press for ramping, each long press ramps in the opposite direction (so you don't have to go all the way to the end if you go too far either direction), and it STOPS at the top & bottom, which is where so many ramping drivers get it wrong...

I will probably bore out the hole in the S1100 and use it there. Would be a big improvement over the stock tail switch off/on & side switch for modes - this driver would let the tail switch function only as a lockout, as it should have been from the start.

Thanks, I have been waiting on this since I had spotted the driver on one of your pictures.
Banggood is selling it too.

What are the KEY contacts for?

Typically 'KEY' is used for momentary switch inputs (or K1, K2). If this one works via conventional clicky switch, I wonder if there's a jumper hidden somewhere that selects between switch type? Or maybe the same PCB is used for different versions.

Here's a LD-36:

...which brings up another question: WTF is 'SEN'?! Sensor? What kind of sensor?? |(

HKJ. I want to purchase some of these, but I have to know if a momentary switch will function properly by connecting to the “KEY” pads. Does something need to be jumped, or unjumped. Or can I hook it up as it is?

The "Key" is not a mode change or a on/off switch.

It will increase the led current slowly when shorted, it goes up to 3.5A led current. The increased value is stored for that mode and I did not find a way to reduce the current again. I.e. my driver now has 3 modes, each with 3.5A through the led.

I tested a couple of my LD-33 which do not look identical to the ones in HKJ's photos. They can output 3A to 1*XM-L, 2*XM-L, 3*XM-L or 1*MT-G2. The output starts dropping at 10.5V even for 1*XM-L.

The Roche F22 uses this driver. It has an electronic switch. I am willing to bet that the key terminals are to connect the electronic switch.

See the first post of this thread

It's likely the clicky version and momentary version are using different firmware.

Very likely—it also seems there are two versions—one that takes a lower block of voltage that can power 1x LED @ 3A, and another that can power 3x LEDs in series @ 3A but requires 2-4 cells.

Very likely—it also seems there are two versions—one that takes a lower block of voltage that can power 1x LED at 3A, and another that can power 3x LEDs in series at 3A but requires 2-4 cells.

My reputation with electrical components is well and truly alive. I bought this led hoping to use it in the OL comp. Having learnt to test everything electrical at all stages to prevent assembling something that does not work testing was commenced.

Someone mentioned above that some batches of these drivers work on 1 to 3 leds I decided to hook up one led to start. It worked fine with 3 modes but had a maximum of 1.5 amps input at about 7.5 volts upwards when the led died. Being an led (yes it was on a heatsink) I put it down to previous abuse and old age so replaced it with another. Yep, it died instantly. Thinking that this driver may not be for 1 led I hooked up 3 in series. Damn. The whole lot blew instantly. Would anyone like to take a guess at where I screwed up. I dont know whether to get another or try something different as this is all rather expensive.

I did check the output voltage with the 3 leds in series after they blew and it was around 15 volts but there was no load from the leds.

What input voltage?

I started at about 7.5 volts and did not really get over about 12 volts.

How do you zap 3 series (XML? XML2?)'s with only 12 volts? And how did you get 15v out with the LEDs disconnected with a 12v input? It's not a boost driver...

I had one of these in the past. Not sure if I killed it, or of it wasnt working properly. Guessing it was me.. Same mistake.. Was just going to do a quick test on a single emitter.. Bad idea.. Afterwards the driver was pretty much direct drive and did not work properly at all. Never used one afterwards.. I have a feeling the driver will die if you use it on a single emitter and 2-3 cells. And so will the emitter as long as its basically direct drive with too high voltage..

Recieved two LD-33 drivers today... Might use one (or two?) for my contest build.. Ill do some testing beyond what they are really supposed to do.. Ill update if I ruin them. :p

Good point. I more than likely had the power supply up around that voltage at the time, 15V after I'd given up. This was a few nights ago and my memory is not the best when its good.