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


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

Official specifications



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

Boost-Buck%203-18V%20Triple%20XM-L%20HL

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.

Boost-Buck%203-18V%20Triple%20XM-L%20HLDriver

The driver changes seamless between buck and boost.

Boost-Buck%203-18V%20Triple%20XM-L%20HLLed

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

Boost-Buck%203-18V%20Triple%20XM-L%20LH

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

High%2014.4V
High%2010.8V
High%207.2V

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

Heat%20throttle

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

Warning

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.

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20medium

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

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20mediumDriver

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20mediumLed

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

Medium%2014.4V
Medium%2010.8V
Medium%207.2V

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



Low

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20low

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

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20lowDriver

Boost-Buck%203-18V%20Triple%20XM-L%20HL%20lowLed

Again I have used a fixed led voltage.

Low%2014.4V
Low%2010.8V
Low%207.2V

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