How to power LEDs for 85 inch TV

  • Hi, newbie here that is intending to make a DIY ambilight for my 85 inch tv. The perimeter is about 6.2m so I plan to buy 2 X 5m LED strips with 60LEDs per metre. I estimate this might draw about 15A power, what is the easiest way to power such a long strip? I read something on the forum about someone feeding power into each of the 4 corners of the TV and using a distribution block but this sounds quite complicated. Is there an easier way to power a long LED strip? Thanks in advance

  • i was online just now and read your story.


    power from both sides > begin and end

    if you don't have to cut the ledstrip in parts then power from both sides above 100 leds is the way to go. ( leave it in one piece and only shorten it at the end)

    VCC > VCC +5volts / and GND to GND


    your setup of 6.2 meter will draw at maximum brigtness 372 leds x 0.049 amps = 18 Amps

    so if you want to connect the strip and more to it you come a little short with only 15 Amps


    you need a PSU of 100 watts or 20 Amps to run this much lights

  • Hi,

    6.2 meters @ 60 LEDs/m are ~ 372 LEDs x 0.06 A = 22.32 Amps max.

    I would feed in at the beginning, end and at every corner, but at least after every meter. The voltage drop at such high currents should not be underestimated. Which LEDs do you want to buy?

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

    Einmal editiert, zuletzt von Mike72 ()

  • I'm very new so not sure which LEDs to get either. A friend of mine who has completed a smaller project for his monitor told me to get ws2812b since he reckons 3 wire strips are easier. Yet the forum on this website suggests 4 wire strips like the apa102.


    Also where do i get a 5v 20A power supply? I'm in Australia and plan to buy on aliexpress but can't find anything over 10A


    Thanks again for your help

  • Ambientheater77: I know, each datasheet says something different values... :/

    I always calclate ~20mA per single LED, others take 49mA per 5050-LED, who knows... ^^

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

  • 4-wire-LEDs like APA102 runs via SPI on the Raspberry Pi "Out of the box". In my experience, 3-wire-LEDs are more difficult to handle, more arithmetic tasks for the RPi over just one data line.

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

  • I would buy a power supply from MeanWell LPS series (no, I‘m not working for this company ?), but these are adjustable, from better quality and minimum expensive.

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

  • Thanks Mike72 and Ambientheater77 for the links. Just to check I've got my shopping list correct for DiY ambilight used only for Kodi, I will buy

    - RPi 4

    - APA 102 5m strip X 2 (no need for RandA since these plug into RPi)

    - Meanwell LRS 5v 100w power supply

    - solder less corner connectors


    Does this seem about right or am I missing something?

  • - RPi 4

    - APA 102 5m strip X 2 (no need for RandA since these plug into RPi)

    - Meanwell LRS 5v 100w power supply

    - solder less corner connectors


    Does this seem about right or am I missing something?

    - RPi 4 >> some types ( memory RAM) will not run hardware with Hyperion.NG

    - APA 102 5m strip X 2 (no need for RandA since these plug into RPi) good choice

    - Meanwell LRS 5v 100w power supply good choice

    - solder less corner connectors those connectors will often cause troubles in current/voltage drop, i would recommend to solder anyway, especially when you have a lot of leds like you do.


    Does this seem about right or am I missing something?



    wire gauge has to be thick enough and before you want to buy PI4 you can also buy PI3b because that's already more then enough to run Hyperion without problems, advantage is that the hardware is somewhat older so every OS/software will run on it.



    experience with OS is; ( OS = Operating System)


    Windows; mostly newer OS software runs the older hardware. ( hardware is older than OS)

    Linux/Debian; mostly older OS software runs the newer hardware. ( hardware is newer than OS)


    so you see its the opposite, thats the reason i don't think its an good idea ( personal take) to have a brandnew PI thats much newer than the software written for it.

    its because the Linux/Debian OS is open source and with windows its pushed with releases and developers who wants to make money.



    a whole story but you get my drift, i would go for a type older Raspi like 3b or 3b+

  • Sounds good. But these solderless corner connectors could produce issues at this high currents. In every case it's better to solder, it's not difficult. ;)

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

    Einmal editiert, zuletzt von Mike72 ()

  • Thanks so much. I have a raspi 3b lying around so I might use this. I was only looking to use raspi 4 since I'm also running Kodi which is a little more processor intensive. I might end up getting a nvidea shield too in which case I prbly have to get a video capture box to connect the raspi if I want to run the ambilight.


    I'll give the soldering a go, never tried it before but it sounds like it's going to produce much better results

  • APA102 have a data line and a clock line for synchronization, less work for the Raspberry Pi. The 3 wire types only have one line for everything. Many users have success with a direct connection to the RPi, some less. My experience is, it works fine with PWM on GPIO18 (Pin12), but you have to run the RPi under root user, deactivate audio (runs also over PWM) and change some settings in the config.txt and cmdline.txt.

    I'm using this little circuit to control the SK6812-RGBW directly from the RPi. It pretends to the RPi, "I am 4 wire SPI hardware" and converts the signals to one data line. It's Plug n' play. But maximum LEDs are 256, so in your case, you should use an Arduino for this work.

    Grüße aus Österreich / Greetings from Austria !

    - Don't wanna miss it anymore !

    3 Mal editiert, zuletzt von Mike72 ()

  • It sounds like it was probably my post you had read. In my case, the distribution block was necessary because I wanted to keep my power supply on ground level and run cables through my wall and out to a mounted tv. The length ended up being about 10 feet. Power will drop quickly if trying to run through small wires (that's also the reason you get power drop within the actual LED strips). That meant I had to use 10AWG wire, which is rather thick. The distribution block allowed me to run the final legs in a more manageable 20AWG.


    I chose to run power to the front and back of each strip on all 4 sides. If I was cutting corners, I would probably just run power to the front and back of the top and bottom strips, and just power the side strips from one end. But what's 2 more runs in the grand scheme of things?


    I also went with a 30 amp PSU (334 ws2812b). It's better to run PSUs at 60-80% for efficiency. You don't really want them cranking out 100% all the time.


    Here's my setup on an 85" tv https://imgur.com/a/Yp0Y0St
    You likely don't need the capacitors and resistor with a good quality PSU, but they definitely won't hurt anything. They're there as more of a failsafe and probably wouldn't be needed with a properly wired system with good connections and a PSU without a voltage spike when powering up.

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