I use one in my edc, coupled with a keeppower 3400mah cell and xm-l 4c, its a very useful light, I have not done much measuring of it, I just use it daily inspecting underneath vehicles.
I can tell you I tend to end up charging the cell way before any noticable drop in output, I also wish it had a lower low, the two group implementation is good though with a slightly longer wait than a similar nanjg and more of a flicker than a harsh on/off routine.
Its best feature for me is constant current in all modes, working around moving machinery, zero pwm is a bonus as pwm can be distracting even with a nanjg.
It really seems like an excellent regulated driver according to this guy graph and you confirmed that.
And one more thing… When I for example put it on med and turn off the flashlight… Will it return on high mode? If so how many seconds I need to wait for this.
This is copied directly from the specs on the website for this driver. Something does not add up here. Constant current, no. Direct drive. Output 2.6 amps.
Electronic Components
CONSTANT CURRENT No
DRIVER TYPE Direct drive
INPUT VOLTAGE 3-4.2 -volt
OUTPUT CURRENT 2600 mA
It doesn’t look all that great frankly, it increases current slowly as voltage falls, then nosedives once the battery voltage is below LED voltage.
Now if you don’t want PWM then its a good idea, but otherwise its unremarkable
Im using one of those drivers. I like it for a certain type of light (small 18650 tube/edc). I have measured both emitter and tail current in the past. I considered efficiency to be good. But I don't have the equipment to make a graph and compare with a 7135 based driver, nor have I done any measurements on much on less than 3,6V. So I cant really tell you how it compares vs a 7135 based driver for sure.
If you see HKJ latest test on a 7135 105C, you will see that the driver is also regulated to about 2,5A with input voltage going down towards 3,35V. Basically in terms of how long they stay regulated, they look pretty much the same to me, assuming both were tested with an XM-L.
I like the LD-25 MUCH better than the typical 105C with hidden strobe/sos. Mainly due to no audible PWM and much nicer mode memory.
The specs FT have on the driver are all over the place, and not correct. Its FT, several of their driver circuits have wrong information.
The main question is, how does the LD-25 and a 7135 based driver compare in terms of efficiency when used on medium and low. Someone needs to make the graphs in order two get the best answer to that. I have a feeling the difference is quite minimal.
When that is said, the LD-29 seem to have great efficiency when used with two cells, how it compares with the other drivers when using one cell. That I don't know. I assume OP have taken that driver out the comparison due to size.
Well isnt current increasing when battery voltage starts to drop good thing for maintaing constant current to led?
Actually I meant that driver for XP-E2 and XP-G2. Forward voltage of this leds is 1A i think.
I have some boost drivers like Deerelight 1SM 3-16V 1,5A. But it also needs 2 battery(16340/18650). 1.5 is not enough
Any idea how to mod this at least to 2-2,5A of current?
I am not sure now… You guys said that there are no plenty of benifts on much cheaper and good old 105c…
And further:
- It is 100% more expensive than 8×7135AMC driver
- It has no reverse polarity protection(it is not for me… I plan to sell few creations and people are mostly stupid when it comes to this, had plenty of cases where they burned my driver with their stupidity)
Mode cycling and last mode memory is not good for my clients. Either high only or no memory when changing modes. From any mode it must return to high.
Guys please invent some single 18650 drivers that can maintain constant current(from 2-3A)to led from 4,2-2,9V(or even lower than that for pana cells) of battery voltage.
A 105C flashed with DrJones' Nlite can be set with the stars to hi-mid-low-moon with no memory, always starts on high mode. Sounds like that's the UI you need, but still doesn't solve the regulation issue at high drive currents. Of course lower drive current will give longer runtime before Vin & Vf start butting heads, but until somebody alters the laws of physics to fit a buck-boost driver onto a 17mm PCB the choices are fairly limited.
