News

moodlite - Coming soon


Questions regarding Amp for power supply

jp · 349

jp

  • Newbie
  • *
    • Posts: 1
    • Likes: +0/-0
    • View Profile
on: February 20, 2019, 11:52:21 PM
Hi! I read somewhere that I need at least 1.5A for every 30 led. I am planning on using 12 led per tile (designing a larger tile with 4 led each corner) and 9 tiles. Should I purchase 5V 10A power supply? or any 6-10A with 5V will be okay? Please advice.



frozenboy

  • Newbie
  • *
    • Posts: 3
    • Likes: +0/-0
    • View Profile
Reply #1 on: February 21, 2019, 03:56:04 AM
Hi! I read somewhere that I need at least 1.5A for every 30 led. I am planning on using 12 led per tile (designing a larger tile with 4 led each corner) and 9 tiles. Should I purchase 5V 10A power supply? or any 6-10A with 5V will be okay? Please advice.

I believe 6A is more than enough, You will rarely turn all led to white, and even if you do it, it will consume 20mA*3ledRGB*120 = 7A.With all led turn white, It will heat and bright so much that we only do for test or stress the led. Full brightness will reduce for led lifetime so much, so don't do it. In daily life, 50-70% brightness is fine, and we often using color so it reduce the power consumption a lot. I'm driving 68 led w2812b with 2A charger and it work fine.
The problem you need to concern is voltage drop down after each led, it make led in the end have yellowish color



mannymiller

  • Newbie
  • *
    • Posts: 19
    • Likes: +1/-0
    • View Profile
Reply #2 on: February 22, 2019, 01:18:40 PM
I keep seeing these crazy amp figures being used,   68 leds with a 2 amp charger is just crazy.  its not just how many leds you are using, but also the distance between each led. some of the palette patterns which include just a few tiles of white, voltage drop can be clearly seen even using an 8 amp power supply.  if cost isnt an issue then go with a 10 amp supply, and when you have completed your build run a second 5v feed to your last tile to reduce the voltage drop. I run mine on 255 full brightness quite often without any issues.

Voltage drop is not good, for either your leds, or your power supply.. Both will get excessively hot, and you will have more chance of your power supply failing.


 i have built hundreds of projects using the ws2812b and never had one fail due to heat being run at full 255 brightness. ( this does depend on the material they are stuck too).  Running some of the palette code in this project which includes the just one or 2 tiles of white voltage drop can be seen, so even though your not running full white, it is still apparent in the other colours too.., just not so visable.

I did a review of this project and had issues, one was volatge drop, the other was a bad esp8266..,   and i show 2 cases of volage drop. this is part 2, in part one i do give full credit to the deisgners of this project.




 


SMF spam blocked by CleanTalk