Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 8 of 8

Thread: How are you all powering your led matrices?

  1. #1
    Junior Member
    Join Date
    Feb 2019
    Posts
    4

    How are you all powering your led matrices?

    Hey I'm planning a 4x2 meter led matrix (horizontal snaking unless someone else has a better idea) of WS2812B leds, of course. I got a 1 meter prototype running nicely using the Octo-shield and Teensy 3.2 I got a few questions before I drop 6-8 Jeffersons on the project though. Will I be good if I just plug the PSUs into the wall and connect them in parallel or is that A) not going to be enough power from one socket, or better yet B) cause a fire inside my walls. I've got 9600 (around 700 amps) leds according to my calculations and I live in the US if that has any relevancy. What fuses should I buy so I can assure the safety of the leds from surges etc. And will i be good with one teensy/octo or am i going to need to pair up a couple/a few (if so how do i do that). thanks for the help everyone.

  2. #2
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    19,452
    How close are the LEDs?

  3. #3
    Junior Member
    Join Date
    Feb 2019
    Posts
    4
    They are 60led/m and will have 4 cm spacing between rows.
    Last edited by Eagletron19; 03-02-2019 at 12:34 AM.

  4. #4
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    19,452
    Are you sure you want such a drastically lower vertical resolution, when the horizontal resolution is 1.67 cm?

    On your original question, you should probably budget between 35 to 50 mA per LED, depending on how bright and what type of animations or video or other content you intend to display.

    If using cheap power switching supplies (commonly found on Aliexpress), you should plan on 65% to 70% efficient.

    So if you have 9600 LEDs at 50 mA and 5V, that's 2400 watts. Using 65% efficient power supplies, you'll need ~3700 watts of AC power. That's much more than you can get from just one USA 120V socket.

    The main purpose of a fuse is preventing a fire if something goes wrong and you draw far too much current. Usually fuses are chosen with ratings slightly higher than the max expected current. Fuses are very inaccurate products. Most take several seconds to blow when run at twice their rated current, and most aren't guaranteed to blow below that threshold.

    Fuses won't protect your LEDs, except in the case where a fire would have burned them along with everything else nearby.

    Many power supplies will have a glass fuse inside. You can always add one in-line with the incoming AC power, if you feel that's necessary.

  5. #5
    Junior Member
    Join Date
    Feb 2019
    Posts
    4
    I am confused on how people have powered their matrices with the limitations of one power socket. Am I missing something?

  6. #6
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    19,452
    Most projects use less than 6000 LEDs, simply due to limited budget.

    I've seen some projects with even just 1000 LEDs where the power supply was quite small, and the code was designed to never turn the LEDs on very brightly. But that has a lower limit, since each LED uses approx 1 mA when completely dark, just to power its controller.

    Many of the big Burning Man projects run from a huge generator, capable of supplying much more than 1 normal AC socket.

  7. #7
    Junior Member
    Join Date
    Feb 2019
    Posts
    4
    Could I simply use more than one outlet for the PSUs? I could also figure out the wiring in my house to make sure that they are not on the same circuit if that is necessary.

  8. #8
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Posts
    19,452
    Using 2 separate outlets should be ok. Best to connect your circuit’s ground to earth ground on both.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •