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I want to control 5m of WS2812 LED Strip with my Raspberry Pi. I found this tutorial: http://popoklopsi.github.io/RaspberryPi-LedStrip/#!/ws2812 There it is stated, that one LED consumes a maximum of 60mA, which makes 9A for 150 LEDS on a 5m strip. I found a 5V 10A Power Supply, but I didn't find a power jack, which supports this much amps. Most support a max of 5A. Maybe there's another way to connect the power supply to the led strip ?

Did anyone build something similar and knows how to power the strip in this case?

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migrated from raspberrypi.stackexchange.com Aug 5 '16 at 19:03

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Divide the strip into two sections, and power each section from their own power cable. So use 2 5A Jacks from the supply. Or skip the jack and wire it directly. You want to power the strip at multiple points due to Voltage Droop anyway.

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  • \$\begingroup\$ How would I connect these sections to the breadboard with the raspberry pi ? I'm a electronics newbie. I'm able to rebuild the constellation of the tutorial I linked in the question, but I don't know how I would rewire and split the led strip etc. \$\endgroup\$ – appcodix Aug 5 '16 at 19:58
  • \$\begingroup\$ @appcodix the strip has cut lines. You would wire the 5V directly to the strips, not to the breadboard. Same for ground. But you need to wire the ground to the breadboard/RPi as well as the data. \$\endgroup\$ – Passerby Aug 5 '16 at 20:19
  • \$\begingroup\$ So I have a power supply for each section. And each section has to be connected to the breadboard? \$\endgroup\$ – appcodix Aug 5 '16 at 20:27
  • \$\begingroup\$ Let me rephrase. The data line could (afaik) be connected between the two strips. You can use two power supplies, or one supply connected to multiple strips. The main data, and all ground cables should be connected together. \$\endgroup\$ – Passerby Aug 5 '16 at 20:41
  • \$\begingroup\$ @appcodix You do not want to use breadboard for currents in excess of about 500 mA : How much current can Solderless Breadboards handle?. \$\endgroup\$ – Andrew Morton Aug 5 '16 at 20:42
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I've got about the same problem here. Several 5m strings of 300 wonderful 5630 LED lights. But the strips require 12V @ 5A. When I need a number of these strips, I either need to raise the voltage and chain them in series (no more than 48VDC, though, to stay under safety guidelines), or else I need to have a very beefy power supply.

Galvanic isolation with a transformer works nice. But have you ever priced one of those things for high currents??? You'll choose instead to learn how to wind them yourself from some retired microwave oven transformer core, pretty quickly.

Or else you'll need to explore isolated switching supplies. PC power supplies start looking nicer. An older 500W power supply might provide 30A on the +12V rail. But for you, wanting 5V, they supply even more -- perhaps 50A? It's still a big box. But it weighs less than some of those heavy transformers used in a linear DC supply. And they are nearly free, if you just look around for a moment.

Don't forget about current carrying capacity over copper wire and sizing that appropriately (which means taking into account longer runs, when applicable.) You should size for twice what the wire carries given the length, as well. If you plan a drop of no more than 0.25V across the wiring (summed on both directions), then at 9A that's still more than 2 watts within the wiring itself. Also, keep in mind that your LED strips will get hot. Luckily, that's over a long length so it is often not such a problem.

I use screw terminals, like these: https://www.amazon.com/dp/B0079G38L6 or these: https://www.amazon.com/dp/B00EZ3QPCU (the first one says 15A, the second one says 8A and is probably too small for your use.) Then I just use a heavy gauge wire and screw it down. But there are similar connector systems which are pluggable: https://www.amazon.com/dp/B00GWF65WY . But just be aware of their current ratings before you buy anything.

I'm assuming you aren't planning on controlling the ON/OFF of the power rail to the LEDs from an I/O pin on your raspberry pi. Right?

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