Actual evidence to support the durability of LEDs.

[JohnnyC]

It's not the switch that's smart, it's the driver. You could replicate the multiple modes simply by connecting and disconnecting the battery in quick succession. The switch just provides an easy way to do this, so don't ignore it yet, it still may be a mode thing, all else being equal.

 

[kr2y5]

Nope, trust me, no modes... and note that I have already confirmed a steady 12.3V @ 2.9A current being drawn from the battery. I presume if switching was involved, that would vary. Unclear to me where this 35W of power is being dissipated if it does not translate into brightness (no heat is being produced that I could easily sense at least), and what sort of fragile electronics are stuffed inside that would fail in this odd manner. I would tear it apart, but I don't want to lose warranty coverage, so that will have to wait.

 

[lucca brassi]

from similar post: ''quality of COB leds at DX''

I would say that are OK for DIY at basic step , but in general their quality vary fluctuates a lot . That mean Vf for single led , soldering quality , color ...

https://www.youtube.com/watch?v=UoxexFBmr0E&feature=youtu.be&t=3m48s

I think these leds in massive sale such as DX are not selected in the peak of Gauss bell but in +/- 2 or even +/- 3 sigma if you know what that mean and also price between 2 and 3 vary.

Same process is (was ) with AMD processors ( that is very actuall at high end graphic cards ) probably with Intel too they are made with for example with 8 cores if same is bad they disconnect one core and you have

operating 6 core processor or you have more or less memory or memory bandwidth..... They work for what they are presented but with lower performance and at lower money scale.

Still is there more profit if you sell something not so perfect for less money on an ''undemanding market '', then you put product ( including production costs ) direct in to the bin .

But look good leds .........have also on DX price!


----------------------------------------------------------------------------------------

PS: most of led lights ( special video ) have bad or wrong construction .......

 

[KDAD]

Did you try to quickly turn the light off and back on? That is how the mode changes. It is all in the driver; it has nothing to do with the switch. It would have to be a quick succession, maybe less than a second.

The LED doesn't require 12.3V to illuminate. It should start to illuminate around 3V and would be at full power at 3.6V. Decreasing the current dims the bulb. I am guessing at which light you have - if it is the one in your profile than your light would only be at less than half intensity at 2.9A. Its current draw at full intensity is 9A. Varying the current varies the intensity of the light.

LuccaBrassi, thanks for the link in your signature.

 

[JohnnyC]

He's already determined that it is not in a different operating mode.

The battery is 12.3V, that's what he measuring. He's also measuring 2.9A (I'm assuming by around one of the battery cables while the light is on), which, if you do the math, works out to just under 35W.

If he was showing 9A of current, it would be running at 108W.

 

[KDAD]

Nope, it's not one of those... and I checked light and voltage directly against battery outlets, where switch was no longer involved.

The mode change is in the driver. The driver is upstream from the switch. You have to power on the light, momentarily turn it off and then quickly back on to confirm that the driver is not a switching mode type.

He's already determined that it is not in a different operating mode.

The battery is 12.3V, that's what he measuring. He's also measuring 2.9A (I'm assuming by around one of the battery cables while the light is on), which, if you do the math, works out to just under 35W.

If he was showing 9A of current, it would be running at 108W.

Not necessarily. The LED emitter only uses app 3.55 VDC at 9A for full intensity which is equivalent to 32W. The LED is upstream of the driver. This is where he should be measuring. The driver is dropping the voltage (it can accept any input voltage from ~6V to over 12V) and providing a constant current.

 

[kr2y5]

Does anyone know of a good source where I can get more background knowledge on the construction of modern dive lights? I have the "Dive light companion", but it is a bit dated. I have not read it back to back, but I do not remember seeing there anything that would talk about voltage reduction, the workings of a "ballast", etc. The designs that are described there are all pretty basic.

 

[lucca brassi]

DIVE LIGHTING LIBRARY

if you can survive :cool2:

 

[KDAD]

^^^^
Also reef central has tons of info on led builds but they are not specific to dive lights. They deal with driving multiple emitters but the concept is the same.

 

[lucca brassi]

When I order leds ( usually MOUSER or LED-TECH ) then I ask them by specific producer code and I also ask them to put leds in to the original antistatic bag with original code on.

No problems at all !

PS: Yesterday i have looked on TV Discovery channel in series ''HOW IT IS MADE '' S24E06 : production of SOLA 1200 I find it on youtube

https://www.youtube.com/watch?v=_Z22HuXaiPs
IMO : that is something i would never bought if I know what is inside , what for hell cool down leds ( that's why I have said that special video lamps have bad construction)

look at 4 : 13 ..........True it is only 1000lm +500lm on eye that mean somewhere 15 W

From picture 6 leds are probably CREE XPG with 5 W each (4 rows emitter) ; spot is probably XR-E with 3,5W each ( together that means 6x5W+3x3,5W =40.5W )

I'm sorry if I'm rude but I like be objective most.