6 meter length, power supply, which led

Hello guys,

A short introducing of myself, i am martijn 38 and i am living in the netherlands.
I have 1 child and if i asked my wife if i we are married she says we are married so i guess that i am married :wink:

In the house i use a domotica controller the Homey, now we are building a veranda and on the homey forum i found a link of Wled so i thought i put a strip led on the veranda.

I ordered 1 meter ws2812b 5 volts 60 leds and it looks awesome, so much respect for the founders and developers it is really great.
But now i have a problem, the intention is to make 1 strip that is 6 meters long but i think i have a problem with the power supply on this length.
I know this is asked many times i think but every project is different.
The intension i also to switch it with a relay because otherwise the drivers are constantly on power.

What is the best solution in total.
use 12v leds instead of 5v?
use different model led’s? Which is the best. Am i right that the ws2815 every led has an adress and not like the 2811 that has every 3 leds an adress.
And how many ampere’s do i need for the 6 meters?

Every suggestion is welcome, and thanks for the answer in advance.

5v should work fine, since 6 meters is not a very long strip. Just make sure to inject power every 2m.

With ws2812 every led is individually addressable
You need around 60 mA for each LED, but only if you want to have them all at the brightest white. That would be around 22A. But in practice, you’re probably not going to set them to all white and then you can use less amps.

In WLed, you can actually enter how much current your power supply has and WLed will adjust the brightness of all light to keep the flowing current under you setting. So you could use a 10A power supply and change the settings in WLed to never go above 9A.

To add to the above very good advice and suggestions, if the LEDs can draw up to 22A, use a fuse to protect your wiring from burning up in case of a fault in WLED that lets the LEDs all hit bright white at the same time.

I appreciate the software limit for what it is. I want to keep the house from burning down in case of a software problem.

Let’s say WLED version 0.19.5b comes out (well into the future) with a new feature you want to try, so you install that version to your ESP device, set things up the way you like, but for some reason the update did not automatically save the current limit and you did not think to verify because the update kept all the other settings you looked at.

Then something strange happens.

Someone who knows you very well and knows all about WLED, but does not know about the smallish power supply, fires up WLED on their smartphone, discovers your LED strip. They want to surprise you so they change your configuration just a little. They set up a preset to launch at 7 pm where it’s full brightness, white, with a solid LED effect.

The next day they stop by at 8pm hoping to see you and ask how you liked their WLED preset that came on at 7pm. Unfortunately, when they arrive, the fire trucks are still trying to put out the fire that started when the power wiring feeding that LED strip overheated and started a fire.

This is not very realistic, but it’s definitely not impossible. Plus, with all the YT pranksters out there, not completely unreasonable to say it could happen.

Hopefully my silly story was entertaining, only slightly scary, and maybe just maybe it gave you the idea that a fuse is not that difficult nor expensive and is really cheap insurance that keeps you from having to use real insurance.

Thanks for the reply’s

It has definitely to be safe because I make everything in an aluminium veranda.

I choose for 5 v sk6812.
So now I choose the power supply, I think the minimum is 25 ampere??

I am only considering about the cables, the thickness of it.
Also what is the best setup, 6 meters and put the power supply in the middle so I can feet from there and go sideways? And put the dataline off course to 1 side.

I am gonna use a quin led dig uno, only feed them positive and negative with an light supply and feet the sk6812 from the other big power supply and do I connect the ground pin to each other.

Sorry for my questions but it has to be safe and good.

25A is more than enough, current will never be above 22A and usually a lot lower.

You can put the power in the middle, but the led’s might be a little bit darker at the ends. You could also inject at 0m, 2m and 4m.

And you have to connect the ground wires of the power supplies!!!

Just a short reply. If you add a safety smart relay in front of the power supply for eg, a Shelly 1 plus PM where I set up the maximum A to 5A, and there is a power switch with 16A on the main power cable of the room that will power down mechanically, I think there is a 3X protect from burning down a house. Plus use 0,75 -1mm of cable minimum.

5V LED strips suffer from voltage drop over longer lengths. The strip by itself cannot handle the total current required from the start of the strip to the end. The only solution is to add extra power wires (injection wires) at one or more points along the strip so the proper voltage is maintained for the strip.

Voltage drop is dependent on the total current and the length (and size of wires) of the strip not the voltage.
Power used or maximum brightness depends on the current and the voltage. This means for the same brightness (power), higher voltage strips need less current so they need less power injection.

How a strip handles higher voltage is up to the manufacturer, some will tie 3 LEDs together and treat them as a single pixel. Others will add regulation in the pixel to drop the 12V to 5V. A third method is to do it yourself and run a “higher voltage” power line along the strip and use buck converters where you need them to drop the voltage down to power the strip.

The power consumption of your strip comes from the manufacturer although a common worst case value is 0.05A/LED or in your case 3A/m. 6m => 18A at 100% white for the entire strip. The best way to know is measure with an ammeter.

Lots of possibilities.

I am planning 6,5m led strip with SK6812 WWA. I need only white but I’d like to change it. There are 8 drawers and if I open one in different period of a day I’d like to see different white with different brightness (home assistant will do it ). But if I’d like a smooth light in the room I want to turn on every led segment. This is the main problem for me the 5V. Factory data is 29W/m that is about 200W and 40A is needed… I dont want that high amps in a furniture but right now I dont have any idea to do this project with one strip only. 12V 6812 RGBW would be a solution but there the white is not so white I believe. How do I have to make the power supply for the 5V 6.5m 6812WWA strip? Thanks.

If I understand you correctly, you’re looking at 8 strips that total 6.5m or ~0.8m /strip.
That’s 29W/m x 0.8m = 23.6W/strip or 4.72A /strip.
Now those numbers are worst case - All LEDs at 100% brightness.

One thing you haven’t mentioned is what the layout and general size of your project wil be.
The distance from the power supply to the strips and the MCU board will be important information.

If the strips will all be close to the power supply, you may be fine with lighter gauge power wires.
As the distance goes up, you have to increase the size of the power wires and you may want think about using a higher voltage (but lower current) power supply with buck converters to let you use smaller wire.

Sorry if I was mistakable. There are 8 drawers in a furniture with U shape and I am planning one led strip with addressable LED with only white color that is variable. In this case there is 8 door sensors and only one led controller in the system and I can do some effects on the stip. SK6812 WWA 90leds/m would be great in 12V but I could find it only in 5V on aliexpress. 6,5mx29W is about 200 W, per5V is 40A which is insane. This is the point where I get stucked. If I use 2 pcs of DC5V10A ps (one-one both ends) that would be enough to use with good brightness on the strip? The 1st power supply and the controller will be about 3m from the start of the strip and the 2nd ps would be about 2,5m from the end of the strip. Hope everything is clear :slight_smile: thanks mate.