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I'm new to electronics and I have a couple of simple questions on how to safely and reliably power a LED strip.

My goal is to have an individually addressable LED strip lamp.

For the strip I've been researching and I've decided on the SK6812 LED strip for its separate white channel. It's powered using 5V and it uses the 5050SMD LED's which consume 0.3W of power each. I have the choice of 30, 60 or 144 LED's per meter and I was thinking of going with either the 60 LED's or 144 LED's. Ideally I'm planning to use 1.5 meters, so I think I would need:

  • For the 144 LED's/meter - 144 LED's * 0.3 W / 5V * 1.5m = 12.96 amps of power
  • For the 60 LED's/meter - 60 LED's * 0.3 W / 5V * 1.5m = 5.4 amps of power

The microcontroler would use some of the power and I've read somewhere that there should be somewhat of 20% surplus of power for the LED strip so that it's not underpowered, so around:

  • 15.5 amps for the 144 LED's/meter
  • 6.5 amps for the 60 LED's/meter

Now it seems to me, by looking at the power supplies that are available, this is quite a bit of power needed. Especially since my project is not too ambitious and I only want to power a simple 1.5 meter LED strip. If I was to go for the 144 LED's/meter - it seems that it would be a hassle of finding a power supply like that and there might be issues with other components.

I'm planning on using the Aircookie/WLED and I would need to split the power from the power supply to the microcontroller and the LED strip (based on diagrams at https://github.com/Aircoookie/WLED/wiki). Now I want this "LED lamp" to be somewhat aesthetically pleasing and I don't want to split and solder the cable from the power supply to the microcontroller and the strip so I was planning on using a female 1 DC to 2 male DC splitter (2.1mm x 5.5mm) that are advertised for security cameras (for example this) and I've noticed on one of these that the maximum rated power is only 5 Amps.

This low power rating worries me. What if I were to go with the 144 LED's/m strip, using a higher power supply? Do I need to worry about other components such as the microcontroller? How do others power long 144 LED's/m strips? Does injecting current every X distance reduce the power needed? Should I go with a strip that uses 12V? If so - are there any recommendations for and individually addressable one that has a separate white color channel?

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    \$\begingroup\$ Tip: "amps of power" isn't correct. Amperes are a measure of current, not power which you have correctly identified elsewhere. Just as we don't say "5 m of distance" but instead say "distance of 5 m" or just "5 m" you can say "= 5.4 amps" or "0.3 W", etc. Current and power are implied by the units just as distance is implied by "kilometer". \$\endgroup\$
    – Transistor
    Feb 13, 2021 at 9:53
  • \$\begingroup\$ I always get those confused, my bad... \$\endgroup\$
    – simplicity
    Feb 13, 2021 at 10:06
  • \$\begingroup\$ Look up definitions for Voltage, Resistance, Current, Power and get them straight in your head. Then look up Ohm's Law and Watt's Law. Those two formulas will help you a lot trying to deal with simple loads like LEDs. \$\endgroup\$
    – K H
    Feb 13, 2021 at 11:56

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Powering individually adressable strips is tricky. If you planning to use it with full brightness, keep in mind the conductors on strip can not hold big current, so you need to run some wires in parallel with strip and connect it to strip in middle. Depends on brightness you are setting. Minimal consumption of one chip is approximately 1mA. Power distribution need some planning. Controller consume small amount of power and provide only data signal. Just common ground and logical level should be proper, according to LED chips datasheet.

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