Help on powering 10+ meters of led strips (30led/m)

Other Hardware LEDs and Multiplexing
1

Hi,
I want to power 13m of RGB led (ws2812b) strips (30 leds per 1m) so I have an estimated of 7.8 amps minimum (following the 1/3 rule power rule.) I want to have these 13 strips of 30 led strips outlining the top of my room (140inches X 110 inches = roughly 12.8m) so they will be running around my room in a rectangular shape. I have a 10amp 5v switching power supply with the male dc power adapter / terminal block that I could use from a prior project.

I know that if I connect these 13 strips together and power it on with just the 10amp 5v power supply I have, that the voltages will drop from the very long resistance of 13m being powered by one supply in the beginning and end. I was wondering if it'd be possible to distribute power from every other strip by having wires from (+ and GND of strip 1,3,5,7,9,11) all the way back into my male dc power adapter terminal block so this terminal block would share multiple wires in it's terminal block thats then plugged into my actual power supply. The problem I see here would be that all the wires wouldn't be able to fit into the terminal block or/and the resistance from how long some of these wires would be away from the power supply that have to wrap around the perimeter of my room back to the single power supply would be too much. One solution I could do is put my power supply in the middle of my ceiling and have all wires from every other strip go back to my power supply to distribute power but even if I did this, the wires from the supply to each strip would be a couple of feet still at some points.

Is there an efficient way to do this using my one power supply or will I have to purchase other power supplies so I can be closer to the other strips in the chain to distribute power evenly? I haven't tried to use my solution I proposed above since I don't want to go through all the hassle if it doesn't work or damage any lights if it did.

Please let me know if I need to clear anything up as I tried my best to explain, thank you!!

2

I don't know the 1/3 rule but better not to try to power them all on then... For that you need 24A. And it's easy to do by accident and blow the supply if you use a 10A model...

Back to the questions, yes it's possible. You do know how to solder I assume?

Just get yourself a nice cable that can handle the current. Assuming 10A a 1,5mm2 should do. Connect that to the supply and run it parallel to the strip. Just tag on the power of that cable to the strip like every meter.

And to make it even better (because it's easy if you make a square), not only connect the start of that cable to the supply but also the end. That effectively doubles the wire thickness.

3

Thanks @septillion for the reply! I was referring to this:

Sorry I figured I'd use the 1/3 rule as I will be only using the strips at night and very dimmed (I won't be using these to actually light up my room, more of just something to look and awe at the cool effects; every so often)

4

Play it safe and test your sketch with only 1/4 or 1/3 of your leds (but keep the full number of leds set in the sketch). Check the current drawn by the circuit usinh your multimeter over the full sequence of patterns, over several hours. If all is well and you estimate the current will not exceed 80% of the PSU's capacity will all leds attached, you can connect them all. You probably won't be able to safely check the current then without risking damaging your multimeter.

5

Paul indeed has a good point. But don't forget to multiply the current you then see by 3 or 4 (because of the 1/3 or 1/4. May seem obvious but yeah....

But don't forget to add a (fast) fuse in line with the leds. Although you don't plane to use them on full it's easy to screw up and trigger all at 100% and blow the PSU...