What is the reason white led's are different colors?

[kingofwylietx]

I was looking at some led worklights and have noticed some appear to be more blue, slight green, cool white, or neutral white from the same manufacturer.

Why is there variation in the white leds? How do they get matching led colors so all their lights are neutral or cool white? Is this what you guys refer to as certain bins? I'd like to tell them how to have all their lights 'match'.

Thank you in advance.

 

[kingofwylietx]

I want to add that I have been reading the sticky 'threads of interest'. I'm still learning, so please be kind.

I suppose my real question is: When a manufacturer orders led's, can they specify a narrow color range and expect to get it in large quantities? Or, are variations in color unavoidable?

 

[alpg88]

few reasons,
poor quality manufacturing, while no 2 leds are exactly the same, quality manufacturers, make that difference in the same batch tiny. poor quality manufacturers, don't, their leds vary a lot more in the same batch.
also in work lights with many leds, most of the time leds wired in parallel to simplify processes, and make it as cheap as possible. but leds are not the same some get more amps some less. that is why you got all different color leds.
i buy leds from china, not made at the best qc factories, so i use breadboard to mach the tint (as much as possible) for arrays, so it looks uniform ,and try not to run many in parallel.

 

[HarryN]

Your best bet today for a tight spec, matching, off the shelf, white "colors" is to buy the CCT and CRI binned Lumileds Rebels part numbers.

They have the generic versions, and then some that are very specific for CCT and CRI. Of course, these carry a price premium, but it is reasonable.

 

[Kuryakin]

Actually, that goes for anyone's LEDs. Get them binned for color, etc., and you'll do well as far as matching goes.

Also, the 'warmer' the white, typically, the less efficient, because more of the light is coming from the phosphor (which has losses going from blue to the fluorescing color) and less is coming from the blue LED under the phosphor.

Your best bet today for a tight spec, matching, off the shelf, white "colors" is to buy the CCT and CRI binned Lumileds Rebels part numbers.

They have the generic versions, and then some that are very specific for CCT and CRI. Of course, these carry a price premium, but it is reasonable.

 

[kingofwylietx]

It's interesting that all the leds in the worklight itself are color-matched. It is just that from worklight to worklight, there is some noticeable deviation in color temperature. I guess I should recommend a tighter color tolerance.