Explain 5 wire LED circuit to me (Christmas lights)?

lumen aeternum

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Have several malfunctioning strings of LED Icicle lights that have a controller that changes the "display."
Two by gemmy.com, one of them at least is their Color Motion Icicle Light:
gemmy.com/set-of-24-colormotion-icicle-deluxe/

One does not work at all; the other lights but the remote controller only works on the very first light in the string.
The control receiver on the string has a lid held by industrial screws with a recessed triangular shape. Tried drilling it out but no luck, so I sawed the top off between the screws. And its potted !!!

So I'd like to figure out how to snip off the controller & connect it to a DC source just so they will light up. But which of the 5 wires to use? There are 24 LEDs on the string, and they are the nice ones with the recessed cone shape, not what they call a "5mm LED."

Should I try a 5v power supply?
 

Dave_H

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Interesting topic though I don't have answers to your questions at this point, but certainly
like to know how these things work.

Can you detail some of the "special effect" behaviour? Is each icicle a fixed colour (appears to be)? They might be (but not necessarily) grouped by colour (I see five).

I have a simple white icicle light set with two-wire interface which carries only dc power (12v). Each icicle
appears to be self-sequencing once power is applied. As each one has slightly different timing, it appears
random after a short time. BTW I applied 5v dc to this particular string and it still runs fine, at much lower
power and slightly reduced brightness. I can see what appears to be a simple voltage regulator (zener)
inside each icicle.

Possibly your 5-wire interface feeds groups of icicles, each with one power wire and one common return wire,
which can control 4 groups simply by selectively turning power on/off (assuming icicles are self-sequencing).

I'm also aware of multiplex control schemes which use pairs of shared wires plus reversing polarity (and possibly PWM
control on top) which makes control a whole lot more complex (but forgot what it's called...anybody?).

If it's a simple scheme, without a controller you could hook up a dc supply and with the right connections, at least see
get some activity but not all the fancy modes.

If you can isolate one icicle and apply 5v dc you could test the self-sequencing; need to figure out
correct polarity, as reverse might damage it. If you can probe wires while it's operating, should be able to.

And yes, if something has a good appearance (and likely cost a bit) I too would want to salvage whatever possible.

BTW you can get so-called "security" screwdriver bits which would handle weird screws including triangular Robertson,
though that doesn't help with the potting.


Dave
 

lumen aeternum

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I have not had time to mess with it... each icicle is an RGB LED.
The remote control cycles thru about 16 color/flash patterns. One was real nice, it had RWB for the 4th of July.

I noticed that one of the 3 strings has replaceable LEDs. Not sure if its the one that is still outside because at least they light up, used to randomly keep changing but this year decided to stay white -- and now that I look, its failed completely. Its not one of the Gemmy.com units, no maker on the box just a PN.

My security bits don't include this indented traingle - you say its a "triangular Robertson" so I can look for that just to add to my collection.
 

Dave_H

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Thanks Katherine, and of course thanks to "Charlie". I was thinking the OP's icicle
lights might use some simple form of C-plexing.

https://en.wikipedia.org/wiki/Charlieplexing

Interesting, but apparently not simple C-Plexing. Looks like serial or parallel RGB data
sent over the same or different wires used for power. That would make debugging a challenge
unless it's simply a case of finding broken connections, if and where it's the cause.

A few years ago I picked up a product called Tree Dazzler which has some similarities.
It consists of eight strings of eight 1" diam. translucent balls each with an RGB
LED. It is designed to hang down from the top of a Christmas tree. Its controller
(which I opened) contains a PIC and other circuits, powered by 12v wall-plug adapter;
but no remote, only buttons on the controller. Each ball has 4 wires going in (R,G,B
and In), and 4 out (R,G,B, Out) except at the end. Local LED driver (if any) and RGB
LED are same package. Just thinking about how this all works.


Dave
 

PhotonWrangler

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If the first LED responds to the controller but others downstream of it don't, I tend to agree that it might be an I2C control with the data output of the first LED or the data input of the second one being bad or disconnected. Do the LEDs each have an external chip nearby?
 

Dave_H

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RGB LED driver I'm vaguely familiar with, Worldsemi WS2811, uses serial data in a daisy-chain setup, with
data in and out lines, but not I2C (data+clock, 2 wires). I2C LED drivers exist but tend to be more expensive,
not the type you'd expect to find in low cost consumer items.

WS2812S is RGB LED with integrated 2811 driver in 6-pin package, and am sure there are other similar
ones out there.

With I2C every device on the bus needs to recognize its unique address which needs to be set up
somehow e.g. pins on device; which is a bit much for simpler drivers. WS2811 is pretty clever in that each driver
strips off the leading data for itself before passing it along. That way, drivers do not need to know an address, it is defined only by their position in the chain.

Not sure if OP's icicle set uses this or something similar, using 5 wires. If it's serial, only the first light
coming on may point to a wire break, but doesn't rule out the controller if it's mangling output data such that it
reaches the first light OK, but nothing further. Or maybe it's power not reaching the other icicles.

Dave
 
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