Boost/Buck 3-18V Triple XM-L Circuit Board

Boost/Buck 3-18V Triple XM-L Circuit Board








Driver is from Intl-outdoor.com, but it looks like it has been removed from his shop.

Official specifications

  • Optimized for 3-4*XM-L LED in series, Low voltage protection and Thermostat protection
  • For 3-4 LEDs:
  • When using 1-2 Li-ion cells in series the driver will act as boost
  • When using 3-4 Li-ion cells in series the driver will act as buck
  • Suitable for 1 or 3 or 4 LEDs
  • Operating voltage: 3-18V
  • Output current for 3-4*LEDs is 2.6A-3A and for 1*LED is 5A
  • Constant current
  • Modes: High-Medium-Low (100%-30%-5%)
  • PWM frequency: 1000Hz
  • PCB diameter: 24mm
  • Contact board diameter: 26mm
  • Height: 17mm
  • Leads: 20AWG
  • Gold plated contacts
  • Tinned leads
  • Thermal management, overheating protection 55-60C, the driver will automatically adjust the output current
  • Low voltage protection 1 cell: at 3V the light will step down to low mode and start flashing 2 times each 5 seconds
  • Low voltage protection 2 cells: at 5.5V the light will step down to low mode and start flashing 2 times each 5 seconds
  • Cut-off after 3 minutes of low voltage warning
  • Thermal pad included (5mm thick)





Measurements

Tested with 3*XM-L2
Diameter 24 & 26mm
Max. height: 19 m
The driver has high, medium and low.
Pwm is at 1kHz
Low pwm is about 3.7%
Medium pwm is about 30%
Does turn off after about 3 minutes with low voltage warning.
The driver has memory, the actual mode is stored when the light is off for a short time.
Uses a 25kHz regulation frequency when turning down output due to heat.
A fast off/on will select next mode.
The driver can be used with 2, 3 or 4 LiIon batteries in series.
Driver can both do buck and boost.
The low voltage warning only works with 2 batteries, not with 3 or 4 batteries.


High



This driver does not use a constant current to drive the led, but varies the current, depending on the battery voltage.
At 5.5 volt it reduces the led current and shows a battery warning.



The driver changes seamless between buck and boost.



Because the current is varies, the led voltage will also vary.



Doing a sweep from low to high voltage, shows that the low battery warning will be turned off when the battery voltage raises.





At high the led is fed with a fairly constant current.



If the driver gets hot, the current is reduced, the regulation is done at 25kHz, i.e. no visible flashing.



The low battery warning is two flashes with about 6 seconds between.



Medium

Because the light uses pwm, I am cheating a bit to calculate power: I have locked the led voltage to a constant value.



The driver is pulsing the current at a fast rate and it is no surprice that it looks like high.





Notice the fixed led voltage, this is a cheat, not a measurement. The correct voltage would be closer to the curev from high.





The pwm can easily be seen on the curves, but are to fast to see with the eyes.



Low



The low level is low and the battery warning uses a higher level.





Again I have used a fixed led voltage.





The driver is using a very short duty cycle for low mode.



Conclusion

The buck/boost function works very well on this driver, but I am not impressed with the low voltage warning. This means it is best to use protected batteries when using 3 or 4 batteries in series.



Notes

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

Interesting review. Thanks.

Thanks for the review, this driver is not for my type of flashlight, but some other drivers that you tested are very useful for me!

I don’t know HKJ. Every time you do a driver review it immediately disappears from the market. If you keep testing drivers, eventually there will be none left for us to purchase.

Better buy your drivers now, I plan on testing many more drivers.

I am a little disappointed that IOS is not selling this driver anymore. It has been the most reliable driver that I have used without a failure (touch wood). A few users did not like the slow mode changes. I never had much luck using this driver on one cell but had no issues running two, three or four cells. Thanks HKJ for another fantastic review.

Thanks HKJ! So nice to get some numbers down on the paper.. Makes picking the right driver for the job easier.

I wonder why int-outdoor stops selling some many different drivers. Hopefully Hank will come get a few amazing drivers that are sweeter. (Probably wishful thinking but...)

I was one of the people who did not like the slow mode changing. Or some of the audible PWM.

I also got the impression that the overheating protection kicked in very soon and limited output. Anyone else noticed that? My setup was 3 cells in series and 3 emitters in series, that was when I noticed it the most. Output went down fairly soon. I did not notice it much with two cells in series, but output and head was lower then..

This drivers seems to be sold by various other stores. On top of my head:

3-mode from KD 15.36$

5-mode from KD - 14.99$

3-Mode from LCK-LED 18.36$

But they cost slightly more, and its from less reliable vendors.

HKJ, will you be testing/ordering the MF TR-3T6 once MF store start selling things again? Im curious how it compares..

I have some drivers from Fasttech I will test when finishes with the IO drivers. I do not have any specific plans after them.

Also due to the many battery reviews I have at the moment, I am a bit slow with publishing driver reviews.

Ok, the MF driver is very similar to this one. Hoping that and this one is your future test list.

I have the big brother (SST90 version) in queue.

Thanks, I should have mentioned that as well..

Hi HKJ, thank you for the awesome review, I've been eyeing this one for some time.

Can you perhaps test it with a MT-G2 and 1, 2 and 3 cells?

Thank you very much

The specification for the driver says 1, 3 or 4 leds, a MT-G2 is more like two leds, i.e. not within specification for the driver. The current does also increase with fewer leds, according to the specification.

The above is the reason I did not test with a MT-G2.

Various info in this thread.

Scroll down to the bottom in this post to get an indication of what numbers you will get on high..