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Author Topic: Tricolor vs RGB LED  (Read 1409 times)
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Is a Tri-Color (red, green and blue) LED the same as a RGB LED?

I'm trying to do some color mixing using PWM and it just looks like three different color LEDs indide a package. It doesn't seem to mix the colors to create anything new.

Ive even tried covering with a lens to blend the light and get not much better results.
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SE USA
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yea they are the same, RGB is just that a RED GREEN and BLUE led packaged into one dome
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I have the same problem with the LEDs I bought.  The cause seems to be that the LEDs are mounted too close to the front of the package.  Other people have reported better results,  and their LEDs seem to have more diffusing plastic in front of the LED dice.

I got some improvement by putting a piece of acrylic rod,  with sanded ends,  in front of the LED,  held in place with a chunk of heat-shrink.  But I'm still not really happy with it.

Bottom line seems to be "Caveat emptor":  get samples before you buy a lot,  and make sure you buy from a vendor who will deliver exactly the same as the samples.

A better diffuser might help, too. Perhaps one of those domes they used to put over incandescent panel lights?

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I have several (they were cheap anyway so no big deal) so I think I'll try and rough up the led housing to create better defusion and I'll report findings.
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Ping Pong balls work really well if you have the room.  Drill a hole the size of the LED and stick the ping  pong ball on top of the LED.  That combined with sanding the top of the LED works really well.  Also I heard of some sort of spray or liquid that is designed to fog up the casing the LED is in.  But I don't remember where I heard of it or what it was called.
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Is a Tri-Color (red, green and blue) LED the same as a RGB LED?
Well it is only as long as you define tri-colour (or even color) as containing three LEDs. However if you search for tri-colour devices you will find that they are devices with only two LEDs in them. This gives three colours, one for each LED and the other from them both being on.
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You will get that with 'water clear' RGB LED's.

I find using 600-800 grit sandpaper to diffuse them, works very well.
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or quicker, let some superglue fog them up
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or quicker, let some superglue fog them up

Like they do in CSI?
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Like they do in CSI?
Yeah a bit like that.

Fogging things with superglue vapour is not very easy and is pretty dangerous...  :o
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The point to remember is that CSI is not real, it's an entertainment TV show with all the accuracy that brings.  smiley-wink
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The point to remember is that CSI is not real, it's an entertainment TV show with all the accuracy that brings.

I'll quickly write a GUI for that in Visual Basic  smiley
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From my favorite online comic:

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