Possible noob question, but has anyone scaled up the addressable LED strip lighting architecture to handle "standard" residential lighting? This would not work well for retrofits, but for a new home construction (as I am involved with), it would be great to be able to install a multi-pair low-voltage cable, hitting lights in two, three or more rooms, with the ability to control them individually.
If compatible off-the-shelf light fixtures don't exist, of course, this would still be feasible for the makers among us to make, either from basic parts, 3D printers, etcetera, or from retrofitting some (hopefully cheap) housings and lenses (if applicable).
Feel free to straighten me out. I hadn't even heard of addressable LEDs until a couple weeks ago!
The problem with scaling up is the very large currents you will need.
This, while only being low voltage, will require thick wires to avoid voltage drop on long wires. A strip will need the power feeding at both ends and also in one or more mid way positions as well, because the thin copper connecting the LEDs in the strip together can not handle these large currents.
Grumpy_Mike:
because the thin copper connecting the LEDs in the strip together can not handle these large currents.
What if the LEDs were only wired in series within the light fixture, while the separate fixtures are in parallel; the overall circuit (in my example including lights for two or three rooms) current only flows from fixture to fixture?
Addressable LED strip lighting is where a (relatively) large number of LEDs in a small area require to be individually controlled in order to produce (moving) patterns. There is a limitation that due to the high data rates used, the possible length of data connection is very limited - of the order of 15 cm between LEDs and a metre or perhaps two for the data input end when driven by a relatively capable buffer such as an Arduino.
The luminaires cited are not addressable - and not in any way intended to be. They have a separate controller which responds to a remote controller - IR if I gather correctly. To operate units widely separated by a common control channel, you need a different system; you could cable the RGB groups from room to room to a common controller or provide individual controllers (and power converters) in each area with some sort of communication protocol and system.
But to be clear, it has no relationship to the system used in the addressable LED strips.
might also become a sensor/speaker/lighting pod, controlling addressable or non-addressable LEDs in that same room.
We are building a new home, I have an opportunity to pre-wire it for future systems, and I am pretty sure I'd like to have low-voltage LED lighting supplementing the 120V lighting inside and out. But I have a lot to learn.
What if the LEDs were only wired in series within the light fixture,
You can not wire addressable strips in series. They are all in parallel. The exception to this is the 12V addressable strip where you can only address the LEDs in groups of three. These three LEDs are wired in series inside the strip.
airwreck:
What if the LEDs were only wired in series within the light fixture, while the separate fixtures are in parallel; the overall circuit (in my example including lights for two or three rooms) current only flows from fixture to fixture?
Grumpy_Mike:
You can not wire addressable strips in series. They are all in parallel. The exception to this is the 12V addressable strip where you can only address the LEDs in groups of three. These three LEDs are wired in series inside the strip.
You had indicated the circuity on the strips could not withstand the higher currents if there was more of a load on it, so I only suggested that if we were to somehow move these addressable LEDs to within a light fixture/bulb/recessed light (any kind of "conventional" non-linear fixture), that within the light fixture they would be a branch off the main trunk circuit, so the excessive current would not flow through them, it would be confined to the trunk (the wires from power supply, to the first fixture, to the last fixture).
But you have to consider the data signal as well, you can’t branch that otherwise you have two sets of LEDs both doing the same thing.
Do you know that with addressable LEDs you have to send data to all the chips at once. So if you do not want a particular LED to change youn send it the same data as you did last time. And the distance between the Arduino and the first pin is limited to about two meters. Any longer and you need to start messing about with differential buffers.
Sorry, but "airwreck" does not seem to quite comprehend what these LED strips actually are!
They are a strip of flexible circuit board with Compound LEDs mounted which incorporate an ASIC chip to control them. They operate on a strictly regulated 5 V supply - though some versions use 12 V and control three adjacent LEDs at a time.
They are not adaptable in any way to different components. The data path chains from one to the next all the way from the end to which data is introduced until the last LED, so if you split the strips, you must convey the data and ground from the split end to the start of the next strip. But you are limited in the distance you can transfer the data from one LED to the next in this manner.
There is a limitation in the current carrying ability of the actual strip. At full intensity, every LED draws about 55 mA, so a hundred would draw 5 Amps and the thin foil conductors on the strip would lose significant voltage along the way at that current. This is managed by running a much heavier (say, 2 mm2) 5 V and ground cable along with the strip and "tapping in" to provide power every 50 or so LEDs so that it feeds power forward along the strip and back from the tap point.
If the power cable does not run with the strip, there is a danger of interference with the data transmission due to voltage drops in different parts, so there is a concern with the careful design of branching power distribution systems.
