How do the new 3-Color LEDs Work

[BryanLeggo]

I just bought a string of LED lights with 15 lights total. There is a controller module at the bottom that determines the coloration and flashing of each of the lights.

Each light socket has only the typical two wires inside and there are there are only two wires for the entire a string, a common wire and then another one that goes to each socket in series. Each LED "bulb" probably has at least a red, blue and green filament inside and they are use to create these 3 colors plus combinations of "mixed" colors (e.g. red + blue = purple). The controller makes each bulb flash and change color indepedently of each other. If there's a pattern to it, I can't see it. It looks random and makes me wonder why they didn't create a program that would do occasional uniform colors or some other more aesthetically pleasing scheme.

Anyway, so here's my question: How do they do this? With only apparent two wires to each node (bulb) it seems like the wiring itself is as simple as possible, yet it produces all these combinations of colors. Is there a trick in the "bulb" itself? How does the controller box affect all this?

I bought these at Big Lots, labeled as Liberty Star Lights (because of the clear plastic Star over each bulb). They also call thgem LED Color Changing lights. I can't find any other clues as to the manufacturer name.

Of course, I'd be interested in knowing if they can be controlled in some other way.

[Videoguy84]

What you're describing sounds very similar to these "FireFly" lights I've seen talked about in this thread: http://lightorama.mywowbb.com/forum76/17480.html

I've only been reading and don't actually own anything like this, so I can merely speculate. I do remember someone mentioned that the circuitry that controls the LEDs is actually built into the bulbs and the "controller" is only there to keep things in sync, so that could explain the simple wiring. But that's about the extent of my knowledge. The possibility of using something like that with LOR is very intriging I must admit. Hopfully someone who knows a bit more then me will chime in

[BryanLeggo]

I'm not sure but it seems like the "Firefly" lights have 4 wires. A common wire, and a red, green and blue wire. That I can understand. It seems like you'd need that to control the 3 colors independently. But these relatively cheap ones that I bout at Big Lots only have 2 wires which makes me wonder how they manage to control the colors or combinations of RGB with only 2 apparent wires.

[John Hertig]

BryanLeggo wrote:

I'm not sure but it seems like the "Firefly" lights have 4 wires. A common wire, and a red, green and blue wire. That I can understand. It seems like you'd need that to control the 3 colors independently. But these relatively cheap ones that I bout at Big Lots only have 2 wires which makes me wonder how they manage to control the colors or combinations of RGB with only 2 apparent wires.

Lets consider the possibilities. If there were only 2 LEDs and 2 wires, you could choose which one would emit by switching the polarities of the wires. But both could not be on at the same time, so only 2 colors. Not likely in this case. That leaves only 2 possibilities. Either each 'bulb' is completely independant and controls its own behavior, which would not require an external 'controller' at all, or control signals are 'modulated' onto the power wires, and each bulb reacts to the signal. I suspect this last case; the signals would have to be sent serially (only 2 wires) so its probably not really quick to change.

[BryanLeggo]

The bulbs do seem to work independently with no rhyme or reason. Although they all get power at the same moment, the colors and paterns they cycle through seem to be random. The "controller" at the base of the string is probably just a voltage converter that turns 110 volts AC into 3.2 volts which is what arrives at each socket. The bulbs are very small so I didn't think there was control mechanism in there but apparently there is SOMETHING switching between the various combinates of red, green and blue.

Too bad. If they can manufacture these for less than $1 per bulb you'd think that it'd be a small step to make the same bulb filaments except with 4 wires total to control each RGB component individually.

[Dennis Cherry]

I bought some three color LED's a year ago. One LED with two leads, looks like a regular LED with a clear lens.

What they have is a small micro chip inside that controls the three LEDS elements and goes through a fixed pattern of color changes in OFF/ON then Fade patterns.

No way to control the colors.

Is this what you have?

[BryanLeggo]

Maybe. Amazingly small microchip then - well under the width of an LED bulb.

[Alan C]

BryanLeggo wrote:

Maybe. Amazingly small microchip then - well under the width of an LED bulb.

Not really. Even a standard microprocessor is really only about 5mm square. The only reason they appear large, is to separate the connections by enough distance to allow them to be soldered onto a circuit board. If you dismantled what you buy as a "microchip", you would discover that the majority of the package is empty.

Regards,

Alan.

[BryanLeggo]

Yeah, knew that but that's what I find so amazing - that they were able to hook the wires up for each individual bulb without the extra elbow room provided by the pins on computer style chips (cases). The width of the wire must be about 1/4 the size of a whole side of a square chip. Now imagine doing that for numerous bulbs.