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I'm considering creating an LED system in my house, and hope to place them within aluminum channels (with an overlying diffuser for effect).

Example

I understand that when running lengths of LEDs, it is often advisable to 're-power' with the input voltage (in my case, 5V) every few meters or so. To avoid running two wires (Voltage and ground), would it be acceptable to run the voltage wire to each location, and connect the ground of the strip to the aluminum channel, and reconnect it ground at the source?

I know that frequently in building homes, copper pipes are used as a ground plane (not in use regularly, only for a ground fault), and is connected back to earth at a designated point. I also understand that aluminum has a low resistivity, but not as low as copper (i.e. a wire).

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  • \$\begingroup\$ Indeed. The trouble you will experience is how to bond to the aluminium. \$\endgroup\$
    – winny
    Jan 23, 2022 at 10:54

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The problem you're going to run into isn't the conductivity of the aluminum, it's how to connect to it. It's not the easiest thing to solder to, so you're probably going to end up with some kind of mechanical connection, in which case you have to worry about using dissimilar metals, corrosion and poor contact. It would probably be easier to just run wires and be done with it.

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    \$\begingroup\$ My first thought was to drill a small hole in the aluminum, add a ring terminal to the wire, and connect it with a small screw, soldering the other end to the LED \$\endgroup\$
    – Will Pike
    Jan 22, 2022 at 22:30
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    \$\begingroup\$ If you can find an aluminum lug that will fit, that will be better than a screw terminal. But if you use a screw terminal use a tin plated one rather than solid copper. I think it might work OK. At least for a while. The more exposed it is to moisture the more likely it is to fail and stop working. \$\endgroup\$
    – user57037
    Jan 22, 2022 at 22:41
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Before you get to far into it seriously consider using 24V strips, that will have a big impact on the current, voltage drop and wire size. I have a whole floor lit with them and it takes over a 100A at 12VDC. That is a lot of copper. Mine came with a translucent diffuser, I chose not to use a clear one, a good choice. I used the double strips with one as daylight and the other as warm white in several areas, they are great and bright. I mounted them on 1x2 dimensional lumber and painted it white for looks. The LEDs typically disperse light in about a 120 degree pattern. I drilled small holes near the ends of each aluminum track and screwed them directly to the wood strips. They have been working without any problems for about 4 years. I used the cheap china power supplies (30 - 50 Amp range)but I oversized them by about 20%, no failures so far. I also have them in just about every cupboard in the house. I used BTS7960 bridges to drive them, that gave me two high current drivers in each module. I did high side because of the lower RDSon. I operate them at about 92% to get extended life.

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  • \$\begingroup\$ Yes, the 5v that OP is considering is very low. I have however used 12v effectively, but I ran it in 4 parallel strips (down the sides of glass cabinets) to minimize the length of each run, if I had to run them serially, I would definitely bump up to 24v as you suggest. \$\endgroup\$
    – Glen Yates
    Feb 3, 2022 at 15:27
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Aluminium conductivity is about 60% of copper, try to calculate cross-section of aluminium profile and you´ll get the equivalent in copper. If the profile is difficult to measure, you can weigh 1 meter and estimate with density. If liquid or humidity can be present, the joining of these metals is risky, in that case bimetallic (search copper-aluminium bimetal) terminals are mandatory. These terminals are common for aluminium wire to copper plate, but you need the opposite, not easy to find. In dry enviroment you should not have problems, only if anodized aluminium is used, take care of grinding the contact surface. Also a isolated supply must be used, and for safety, these metal parts should be connected to ground.

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Unless you're using adressable LEDs like WS2812B, it is preferable to use 24V LED strips. They use less current for the same power, which makes wiring a lot easier. Addressable LEDs like WS2812 are nice, they're fun to use, but they're for decoration and not for lighting, because they can't produce a decent white. And they use a ridiculous amount of current.

If you do not need the addressable feature, and only want color, then a 24V RGB strip would be easier to use due to the lower current. I'm having trouble finding RGBW strips with good whites (ie, CRI>95) but you can always put one RGB and one white or warm/cold strip in the same profile.

Regarding your wiring issues, I'd recommend using this sort of profile: enter image description here

There are two sizes, you can put one strip in the small one, and two parallel strips in the large one. The nice thing is the cavity in the back, which you can use to run your wires. It is a bit larger than the profile you posted in the question, which may or may not be convenient, but since the diffuser is further away from the LEDs, it works better as a diffuser and produces less glare.

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  • \$\begingroup\$ Thank you for your input - I am indeed using the Addressable LEDs (specifically WS2812B). I agree about the limitations of 5 versus 24V…the most ideal strip in my eyes would have an addressable chip like the WS2812B but be 24V. \$\endgroup\$
    – Will Pike
    Jan 23, 2022 at 22:25
  • \$\begingroup\$ There are 12V versions, I've used GS8208, they suck. Huge current draw when off, and you can't turn off the power because when turning it back on, they all flash to say hello. \$\endgroup\$
    – bobflux
    Jan 23, 2022 at 22:30

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