Luxeon V segments..

Hi,

is it normal that in Luxeon V two segments are brighter than other two ?

not on my NUWAI ALX-654C.

yours must be faulty.

sorry.

I can see that when the LED is not at full power. Just enough to lit it up...

Currently I can't check that at full power...

The LuxV consists of two series of two dies ... and when they aren't perfectly matched for Vin OR when one of the two is faulty you'll see a difference in output.
Now ... normally ... this should not be there, BUT ... as you are looking at it when it barely lights up I am not so sure if it is pathological. We will have to wait for our experts on this. :thinking:

TIP: You can look at a full-powered LuxV by using a CD or any other barely-transparent material as a filter ... and thus you can check if there is a difference at high power ...

bernie

I have seen this on a few V's at low power.I would think it is a Vf issue like Bernie said.

C

Kiessling said:

[...]
TIP: You can look at a full-powered LuxV by using a CD or any other barely-transparent material as a filter ... and thus you can check if there is a difference at high power ...
bernie

Click to expand...

Thanks for this tip ! I'll try that !

Christoph said:

I have seen this on a few V's at low power.I would think it is a Vf issue like Bernie said.

C

Click to expand...

Ok, question is, can I power this LED at full power without risk ?

What will be resultant Vf ? I guess two segments have lower Vf and they can be a little overdriven when other two will work at full power...

How this segments are connected: parallel or serial ?

This is my first (and only) Luxeon V LED so I have questions.

No two are perfectly identical even if the bins are the same because each bin has a range and each led may fall in a particular bin but in a different range of that bin. You may see a slight differnce under low power, you can even see a difference at full power if you look at it with a welding filter or similar shaded filter.

As long as you don't overdrive :devil: it it should last as long as any other V It is just one "chip"now.

C
PS I just looked at three V's I have here at work and they all have some differances in the die.