Review: LD-30 1/2AA boost circuit.

Flashlight Modding and DIY Parts
1

OVERALL RATING

:star: :star: :star: :star:

Bought it from http://www.intl-outdoor.com/ld30-boost-12aa-cell-circuit-board-p-417.html.

Mine is powering a 3C, XM-L LED in a 2C maglite. DMM= Extech MN36, autoranging thingy.

PERFORMANCE:

WITH TWO NiMH, C size, LSD cells: (freshly charged)

There are two groups of outputs:
GROUP 1): Low, High. Here current draw: Low= 20mA-30mA and High = 960mA- 1.06A
GROUP 2):Low, Medium, High, SOS, Strobe. Current draw: Low= 20mA-30mA, Medium= 90mA-100mA and High= 960mA-1.06A

WITH ONE CELL:

When the flashlight is together as it should be, I get the same two groups as with two cells:
Group 1) Low= 50mA-60mA, High
Group 2) Low, Medium, High, SOS, Strobe.

As discovered (Post #12), this ramping is actually the driver’s low voltage warning.

LOW VOLTAGE WARNING:

With TWO cells, the light went into low voltage warning when the voltages of the cells measured 1.10V and 0.97V (2.07V Unloaded.) For rechargeables, this is a good warning point since it is illadvised to drain NiMH rechargeables below 0.9V under load.

OUTPUT:

Low has an output I’d guess of around 6-10 lumens. It’s pretty much double the output of my 3 lumen lights.

Medium is not much brighter than low. Again, I’d guess that it’s probably double the output of low which would make it close to 20 lumens or more. In comparison to my EDC host with 4X 7135 Nanjg driver and 4C XP-G, I’d say that medium with the LD 30 is a little brighter than the 4x7135 driver on low.

High output is a little dimmer than a 3x 7153 driver on high.

In general, low is pretty low, medium could be a little higher but, has a big enough increase in lumens to be satisfying and high is good. Given that the host I’m using is a 2C maglite, the outputs are bright enough and spaced far enough apart that I can’t complain.

PWM:

NONE! I can’t see any flickering at all!! Yay!

OUTPUT: :star: :star: :star: :star:

Something else to note. The output wires are connected to some inconvenient places on the board so if you must remove them to add your own, be careful. These wires are a bit thicker than the standard thin, red and black wires that come with Nanjg drivers so they may not need to be replaced.

The driver has memory. If the light is turned off for a second or more, the mode is memorised, if it is turned back on before a second is up, the light comes on in the next output level.

GOOD

  • Acceptable output seperation.
  • Comes with pretty thick output wires.
  • Has a functional low voltage warning.
  • Can use it as a two mode, low/high light without blinky modes.

BAD

  • If you want to use medium, you have no choice but to suffer through the strobes.
  • The driver looses low, and medium outputs when powered by two PRIMARY lithium cells.

CONCLUSION
I like this driver. It performs as advertised, has no PWM flicker and best of all, has a functional low voltage warning. I DO recommend the LD-30 driver to anyone who desires a 1/2AA boost driver!

Any questions or requests, message me or post here.

2

If you want to do a more thorough test for PWM just take a picture of the LED while it is on. If there are lines in the image then there is PWM. (There most likely is PWM due to the type of circuit)

Also, are those numbers tailcap current or LED current?

3

Yes. Tailcap currents. I shine the light on the spinning blades of a fan to detect PWM. Even with the 4000Hz of the Nanjg drivers, I see flicker.

4

The other ld series boards are current controlled on all levels, why assume this one is not?

Eebowler, you seem to be testing all the drivers I’m interested in, nice one. :bigsmile:

5

Thanks for the review. It sounds like an interesting driver. I wonder if it has more hidden modes like the 4 amp driver IOS has? At $8.99 it is at the top end for prices on AA drivers.

6

Thanks for your review. Sounds like a nice Mag build-very practical, and should give pretty long runtimes on 2C/2AA. The LD-30 seems a little on the pricey side for a 2AA driver but the smart design choices are probably worth it. Its version of mode memory is also plain better than Nanjg drivers, which memorize mode after ~2-3 seconds of being ON. I bet it’d be a good driver for a low voltage P60 mated with a reverse clicky.

7

I have build a LD-25 (2A) driver (also from intl-outdoor) into a flashlight. It starts doing that what you call 'ramping mode' when the driver finds the voltage too low (the intl-outdoor specs for the LD-25 say 3V), as a warning. However it started doing that with a cell still at 3.75V, that is quite annoying, and when the switch was bypassed it worked normal. Apparantly the resistance of the switch caused enough voltage-drop for driver to detect a too low voltage. I can't imagine the voltage-drop from the switch is 0.7V (I measured the switch at 0.0 Ohm), so either the driver must be set too sensitive, or my battery is so crap that the voltage drops dramatically under load (going to test that..).

8

djozz… I figured as much it could be due to high resistance due to a bad contact but, still refuse to believe that it’s the warning mode since it is specified in the description that ” *Low voltage protection: The light will step down to low mode and start flashing” Interesting though. I’ll use an AA cell and monitor ‘ramping’ as it dies.

9

Ok I'll make a wild guess and say it needs an slectric switch to stop it while it's ramping in order to stop & select it ...

10

I tried all sorts of things to make it into something usefull, but it really is not a ramping mode. And the maximum brightness while going on and off is around the medium setting, not the high (this counts of course for the LD-25 driver that I am familiar with).

11

Sounds decent… I’m going to look into this for an AA build.

12

Yeah. I measured current draw of only around 400mA max when it’s ramping… And yes, like you, I’ve tried a LONG time to accomplish something with the ‘ramping’ and nothing useful has come out of it as yet.

13

UPDATE:

I ran two AA cells down in the light and around open circuit voltages of 1.10V and 0.97V, the ‘ramping’ started. So YES, as djozz stated, this ramping mode is simply the low voltage warning. Note, the cells were removed from the light and voltages checked so I’m sure that the total measured voltage of 2.07V was higher than the voltage necessary for low voltage warning to be activated.

I also tested the driver with three NiMH cells and it lost low and med modes. This driver will not function as advertised for 3x NiMH or LiIon cells.
Tested the driver with a single LiFePO4 cell and the lowest output was significantly brighter, as bright as medium. I can conclude that with a LiFePO4 cell, the driver does not function as advertised.

Test the driver with two primary Lithium cells and low, med and high are all the same brightnesses.

14

Thanks very much! Sticky’d.

15

Just tried that, but no. Same issues djozz and others describe above.

16

Is there a good summary anywhere of how the LD-30 driver ought to behave, and how it does behave, with 1xAA (1.2v or 1.5v or 1.8v)?

How about the earlier LDCH drivers?

Anyone here in Thailand, or who knows what became of the “ThaiCPF” website?

I found a page there a while back that — as best I could tell with machine translation — summarized the LDCH drivers.
I can’t find that info now, anywhere online.

Here’s what Google turns up, but the links are dead:

17

This may help with your question keeping in mind that there appears to be several different versions of this driver depending on where its purchased from.

18

NEW VERSION:
Hey all. I got a couple LD-30s from Simon on aliexpress. They do not have ‘LD-30’ written on them but are similar in design to the original driver from above.
.
I HATE THEM!!
1)With one freshly charged, C size, NiMH cell, I get a low that’s almost sub lumen, medium is 310 mA and high 570mA. The difference between high and med are hardly noticeable. There is also a horrible flash when going from high to low. Before I freshly charged the cell, it was charged less than a month ago and unused… The driver would go from moonlight to medium then flash and go to monlight. It did not go to high, it did not give any low voltage warning.
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2) Before testing with the NiMH, I initially put the driver in a 2D maglite. It would come on in moonlight, go to moonlight 2, (a minuscule amount brighter) then go to medium. I thought the cells were too depleted so bought two energizers and got the SAME RESULTS. This maglite initially had a 400mA nexgen from the sandwichshoppe which performed without a hitch with the same old cells.
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3) With any of the D cells, new or old, the driver does its moon, med, flash thing again.
4) with a depleted primary lithium, AA, (1.63 unloaded V,) it also does the moon, med, flash…

.
The whole reason for buying this driver was to upgrade the 2D mag so it will have three modes and now, even with two D cells in series, it doesn’t do what it is supposed to do.

EDIT; I have one of those 2596 buck drivers/chargers. I’ll connect a voltage display and connect it up to the driver asap.