MC-E RGBW LED

[Flashlight Aficionado]

Can the dies be controlled individually to create a spectrum of different colors? Or can it only be only one die on at a time? If all the dies are on, will it be white? (where the light of the RGB converge of course)

Cree MC-E RGBW

 

[saabluster]

Re: MC-E WRGB LED

Can the dies be controlled individually to create a spectrum of different colors? Or can it only be only one die on at a time? If all the dies are on, will it be white? (where the light of the RGB converge of course)

Yes, no, and yes

 

[Flashlight Aficionado]

Re: MC-E WRGB LED

Thanks! The Quark RGB can have one die on at a time. So it should be yes, yes and yes. YouTube of Quark RGB

Got any links on how to do control them individually to produce any color I can dial in?

 

[carrot]

Re: MC-E WRGB LED

Thanks! The Quark RGB can have one die on at a time. So it should be yes, yes and yes. YouTube of Quark RGB

Got any links on how to do control them individually to produce any color I can dial in?

No, I'm pretty sure it's actually yes, no, yes.

In order to run each die independently you would want to run each die with a separate driver. Pretty much any LED driver would do.

 

[WeLight]

If you want to mix colour you really want an RGBW controller that will in fact control all die, independently and together

 

[Magic Matt]

Can the dies be controlled individually to create a spectrum of different colors?

Yes.

Or can it only be only one die on at a time?

You can use any combination you like. If you want to only use one or two that's fine too!

If all the dies are on, will it be white? (where the light of the RGB converge of course)

Probably not, but it will be white-ish. I believe that's why you have a seperate white die.

 

[saabluster]

:sigh:

 

[AnAppleSnail]

Look closely at any MC-E. The dies will either have separate solder pads, or a clumsy tech will have soldered them together.

That's the White MC-E, but: Each die has a pair of pins (one on each side). The forward voltage of the R, G, B, and W die will be different, so control will be tricky.

So: You can control each die separately. You'd have to do Math to find where the R=G=B to create white, as I don't know their relative brightness. If you had a separate, infinitely variable CC driver for each LED, you could probably create any Color, and add White to it (washing the color out). Thoughts?

 

[Flashlight Aficionado]

:sigh:

What was said that was misinterpreted or wrong?

 

[saabluster]

What was said that was misinterpreted or wrong?

"Probably not, but it will be white-ish. I believe that's why you have a seperate white die. "

 

[Magic Matt]

I bought 4 from here
http://www.leds.de/en/High-Power-LEDs/Cree-LEDs/Cree-MC-E-4CT-RGBW-A5-K-with-pcb-star.html

Unless they are faulty, having all the emitters on driven in tandem from a constant current supply of 350mA, the light is a bit orangey... I suppose you could call it warm white but it's not like the other warm white LEDs I have.

The white die on it's own gives a nice white light pretty close to my other warm white LEDs.

The three RGB on together without the W die are very off-balance... too orange to be warm white IMHO.

YMMV I guess, but I can only go on what I have here, and I would describe it as "white-ish". If I were wanting to produce white, I would use the white die alone, as the RGB dies on shifts the balance too much for my liking.
Edit: Or as AnAppleSnail suggests, use a driver that lets me vary RGB individually to mix the white properly. By default, they seem to be out of balance when driven with equal current per channel.

saabluster - please can you tell me what is so wrong about that, that you think it deserves a "sigh"?

 

[spencer]

If you want it to produce white then get a white LED or just use the white die. This LED is meant for all the dies to be driven separately to create a very large range of colours.

 

[Magic Matt]

If you want it to produce white then get a white LED or just use the white die. This LED is meant for all the dies to be driven separately to create a very large range of colours.

My only critisism of that would be that with balanced white not being the equivelent to the RGB driven at the same current, it makes the maths more complex in your processor, or you need some fine-adjustment in hardware (small pots?) to balance the colours.

 

[spencer]

But its the only way. They aren't going to make one die less efficient just to make everything balance to a nice white. It would be more heat and nobody want that.

 

[Magic Matt]

The spec has a fairly low lm for the blue at 350mA ... I got the impression that's exactly what they had done, but if anything over-compensated.

 

[Flashlight Aficionado]

The three RGB on together without the W die are very off-balance... too orange to be warm white IMHO.

YMMV I guess, but I can only go on what I have here, and I would describe it as "white-ish". If I were wanting to produce white, I would use the white die alone, as the RGB dies on shifts the balance too much for my liking.

Could you post a picture of all four dies on, pointed at a white wall?

 

[saabluster]

saabluster - please can you tell me what is so wrong about that, that you think it deserves a "sigh"?

The fact that you seem to think that you should be able to send equal power to to each LED and get a perfect white. RGB together gives you white. This LED gives you many many options for what white you want but you can't expect to throw a 7135 per chip on there and call it a day. The sigh was because I am PMSing.

 

[saabluster]

The spec has a fairly low lm for the blue at 350mA ... I got the impression that's exactly what they had done, but if anything over-compensated.

Keep in mind they only spec the minimum flux for those LEDs. Since they aim low this allows them to put basically whatever they want in there. I imagine the majority of the time the spec will be a good bit over spec. It is just a way of simplifying things. Otherwise the various bin options could really get out of hand when dealing with four different types of LEDs.

 

[Magic Matt]

Could you post a picture of all four dies on, pointed at a white wall?

Not for a couple of weeks - my Canon 20D is off having a service (ok, ok, I dropped it, but it is insured) and the phone camera only has auto white balance so the tint would be lost. Happy to do so when it comes back!

 

[Flashlight Aficionado]

Not for a couple of weeks Happy to do so when it comes back!

Thanks! I will wait.