Vastly different LEDs are the same price...why?

[treez]

Hello,

This regards the fact that cree sells two different variants of the same LED, with vastly different brightness, but they are the same price.....why?.....surely the much brighter LED should be more expensive?

MX6AWT-A1-0000-0007EA = 67 lumens at 300mA

MX6AWT-A1-0000-000E51 = 114 lumens at 300mA

Tthis is seen on page 3 of the MX6 LED datasheet....

MX6 LED datasheet
**broken link removed**



if you type those part numbers into digikey.com, you can see that these LEDs are the same price.........so why would anyone ever buy the dimmer one if they are the same price?

 

[yassin.kraouch]

Hi Trezz,
where do you see that the price are the same?? the unit price of the two LED are not the same,
0.80666 for MX6AWT-A1-0000-000E51
0.88000 for MX6AWT-A1-0000-0007EA-ND

 

[treez]

yes but the difference is just 8 cents.......so they are approximately the same in price.....when you consider the vast difference in brightness, they should be further apart in price than just 8 cents....surely you agree?

 

[dick_freebird]

If the only value is in the brightness, then yes. But there
is physical and labor input regardless, and not much of a
difference there.

But as one of my VPs was very fond of saying, "cost and
price are unrelated". Pricing is what the market will bear,
and whether or not you are satisfied with that relative
to your mental model of what should be, is irrelevant -
other than, you buy it or you don't. Cree doesn't care.
The distributor bought the LEDs already.

 

[godfreyl]

You're comparing cool white with the warmest of the warm white. For LEDs in the same color group, there is much less variation in brightness.

 

[treez]

You're comparing cool white with the warmest of the warm white.

.....in our application, these white leds will be used in an amber flashing beacon, and so there will be an amber diffusor over the leds....so it makes no difference whether we use "warm" white or "cool" white.
In truth, in most applcaitons i doubt customers care less whether they get "cool" white or "warm" white......but if theyre going to get 40% more brightness for the same cost, then im sure theyll choose the "cool" white.
All this stuff about shades of white is nonsense anyway................i just read that fluorescent lights give off a "horrible" yellowy white, and that incandescants did too...and that LEDs give off a much more nicer white........................well.......i've lived and worked under all these type of whites, and never once noticed that i was being bathed in "horrible" white light.................but if you tell me that one type of white gives 40% more brightness for the same cost, then i'm there.

 

[FvM]

.....in our application, these white leds will be used in an amber flashing beacon, and so there will be an amber diffusor over the leds....so it makes no difference whather we use "warm" white or "cool" white.

Really? I would expect higher efficiency by using mono-colour amber LEDs, but I may be wrong. "Amber" spectral power will be different between cold and warm white, however.

All this stuff about shades of white is nonsense anyway................i just read that fluorescent lights give off a "horrible" yellowy white, and that incandescants did too...and that LEDs give off a much more nicer white........................well.......i've lived and worked under all these type of whites, and never once noticed that i was being bathed in "horrible" white light.................but if you tell me that one type of white gives 40% more brightness for the same cost, then i'm there.

It might be irrelevant for simple signalling purposes, but "shades of white" matter a lot in daily lighting applications. Most people will know this just by "seeing" without reading a paper. CFL are made with different colour temperatures similar to LEDs, and might expose an unpleasant colour cast (e.g. green, yellow, violet) in addition to their nominal cold or warm tone.

Beyond obvious tint of light sources, their exact spectral distribution affects the appearance of colours. Halogen incandescent lamps, some high pressure arc discharge lamps (like Xenon) and of course sun light are the only light sources that allow "objective" colour reproduction. Recent white LEDs come quite near to it, but have still gaps and peaks in the spectral distribution.

 

[treez]

CFL are made with different colour temperatures similar to LEDs, and might expose an unpleasant colour cast

...may be so but i have certainly never noticed, and i certainly wont pay 40% more for a "warm" white lamp. I'd just take the "cool" white and pocket the difference..............but that's just the point.........there is no real difference in price between the above two part numbers.....why is this?

If i went into work, and said to the boss that i didnt like the "cool" white lighting, and please could he change to "warm" white.....his answer wouldnt be repeatable on this forum.

I think you may get my drift......so why is the "warm" white, which is 40% less bright, costing the same as the "cool" white.?

 

[godfreyl]

....so why is the "warm" white, which is 40% less bright, costing the same as the "cool" white.?

If I was you, I'd spend less time fretting about that and more time looking at the graphs of spectral distribution on page 4.

With the amber diffuser in place, I strongly suspect the 94 lumen version of the 2'nd warmest white will be brighter than the 114 lumen cool white.

A lot of the output from the cool white LED is blue and ultraviolet, which will be filtered out by the diffuser. It's yellow/orange output, which is what you want, is much lower.

 

[treez]

thanks, i see what you mean in relation to the amber flasher, ill check out the wavelengths in more detail.

But we have another application for white light, and the original question, in the first post, still absolutely stands.

Going back to the "amber" flasher, sometimes the diffusor is blue, sometimes red, and sometimes orange, sometimes clear.....we tend to just use white leds, and then any of the diffusors can be used with them....saves us having to spec different leds for different products.