Review/test of LD-29 2.8A 1/2 Cell Circuit board

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Driver is from Intl-outdoor.com, but he does not sell it anymore.

Official specifications:

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 XM-L2
Diameter 18.5 mm & 20.2 mm
Max. height: 9.3 m
Strobe 15 Hz 44% on time
Mode set 1: High, medium, low, Strobe, SOS
Mode set 2: High, medium, low
When doing a low to high test the led did not turn on.
The driver has memory, the actual mode is stored when the light is off for a short time.
A off/on will select next mode, the off has to be rather long, not to select next mode.
The driver can be used with 1 or 2 LiIon batteries in series.
The low voltage warning only works with 2 batteries.



High

LD-29%202.8A%201-2%20Cell%20HL%208.4V

The drivers has very good regulation and good efficiency. It turns down power at 6.5 volt and battery warning comes on at 5.8 volt.
As usual efficiency and power calculations are wrong when the light is flashing.

LD-29%202.8A%201-2%20Cell%20HL%208.4VDriver

There is a maximum of 1.6 watt lost in the driver.

LD-29%202.8A%201-2%20Cell%20HL%208.4VLed

And a bit above 9 watt to the led.

LD-29%202.8A%201-2%20Cell%20HL%205.0V

With one cell, the stabilization is not that good (Led current varies between 3 and 4 volt).
The driver drops to medium mode at about 3.3 volt, this is good for keeping the led on.
There is no low voltage protection, but the driver turns off at 2.5 volt, i.e. minimum voltage for 2900/3100/3400 Panasonic cells.

LD-29%202.8A%201-2%20Cell%20HL%205.0VDriver

With one cell the loss in the driver is slightly lower.

LD-29%202.8A%201-2%20Cell%20HL%205.0VLed

LD-29%202.8A%201-2%20Cell%207.2V
LD-29%202.8A%201-2%20Cell%203.6V

The output does not contain any noise.

LD-29%202.8A%201-2%20Cell%20Warning

The low voltage warning is slow (2 sec cycle) flashing on the led.



Medium

LD-29%202.8A%201-2%20Cell%20HL%208.4V%20medium

Medium has the same good stabilization and does not step down, it goes directly to low battery warning at 5.8 volt.

LD-29%202.8A%201-2%20Cell%20HL%208.4V%20mediumDriver
LD-29%202.8A%201-2%20Cell%20HL%208.4V%20mediumLed

The led power is 2 watt.

LD-29%202.8A%201-2%20Cell%20HL%205.0V%20medium

With lower led power, the driver can sustain the medium level down to about 3.1 volt and it has very good efficiency.

LD-29%202.8A%201-2%20Cell%20HL%205.0V%20mediumDriver
LD-29%202.8A%201-2%20Cell%20HL%205.0V%20mediumLed

Also with one cell the led drive level is 2 watt.

LD-29%202.8A%201-2%20Cell%207.2V%20medium
LD-29%202.8A%201-2%20Cell%203.6V%20medium

Again a very smooth output, no traces of any pwm or driver regulation.



Low

LD-29%202.8A%201-2%20Cell%20HL%208.4V%20low

On low the regulation is also good, the efficiency is slighty down.

LD-29%202.8A%201-2%20Cell%20HL%208.4V%20lowDriver
LD-29%202.8A%201-2%20Cell%20HL%208.4V%20lowLed

The led power is about 0.3 watt.

LD-29%202.8A%201-2%20Cell%20HL%205.0V%20low

With a single cell the driver works down to about 2.8 volt, before brightness drops of.

LD-29%202.8A%201-2%20Cell%20HL%205.0V%20lowDriver
LD-29%202.8A%201-2%20Cell%20HL%205.0V%20lowLed


LD-29%202.8A%201-2%20Cell%207.2V%20low
LD-29%202.8A%201-2%20Cell%203.6V%20low

Again a very smooth output, no traces of any pwm or driver regulation.



Strobe

LD-29%202.8A%201-2%20Cell%207.2V%20strobe
LD-29%202.8A%201-2%20Cell%203.6V%20strobe

The strobe is at 15 Hz and the brightness depends on the batteries voltage (The driver cannot reach full brightness with 3.6 volt).


SOS

LD-29%202.8A%201-2%20Cell%207.2V%20sos
LD-29%202.8A%201-2%20Cell%203.6V%20sos

With SOS it is the same.



Conclusion

The driver is a very good stabilization (Except on high with 1 cell) and good efficiency. The mode change could be better.
There is also very little space for mounting of the two led wires.



Notes

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