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I have an LED strip with 62 LEDs. The type of the LEDs is WS2812B. I am powering them with a 5V 10A switching power supply.

When I set the LEDs to white and full brightness, they look a bit red-ish. I know that this might happen when the voltage drops.

Why does the whole strip become red-ish? Aren't only the LEDs at the end supposed to be affected?

Why would this happen with only 62 LEDs anyway? I have a 1.5m cable between the LED strip and the power supply. Could that be an issue?

I should note that when there are only 41 LEDs instead of all 62, the white looks fine.

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  • \$\begingroup\$ Please provide a data sheet link to the exact LED you are using. Read this carefully: the exact LED. \$\endgroup\$
    – Andy aka
    Dec 5 '20 at 13:51
  • \$\begingroup\$ And measurements of actual voltage and current. \$\endgroup\$ Dec 5 '20 at 13:59
  • \$\begingroup\$ This is the data sheet: cdn-shop.adafruit.com/datasheets/WS2812B.pdf. I do not have a multimeter yet. One is on the way and should be with me tomorrow. \$\endgroup\$ Dec 5 '20 at 14:08
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The data sheet does not tell the current, usually full white can mean 60mA per LED. For 62 LED you're getting close to 4A. Good thing your power supply can do 10A.

Since the whole strip colors, there seems to be low enough resistance inside the strip, but I'd feed the power to both ends of the strip to be sure regardless.

The limiting factor might be the thickness of your power wires. I'd use AWG 22 or 20 for +5V and GND, separately frome the source to each end, to be on the safe side.

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  • \$\begingroup\$ To power both end of the strip, do I need two power supply? Or can I just connect another cable from the same power supply? \$\endgroup\$ Dec 5 '20 at 14:53
  • \$\begingroup\$ @TahnikMustasin You can use the same power supply. There are many guides online explaining how to wire WS2812B strips. If you're unsure why voltage drops across the strip, I would look at one of them. \$\endgroup\$ Dec 5 '20 at 15:13
  • \$\begingroup\$ Connecting both end of the strip to power fixed the issue. \$\endgroup\$ Dec 5 '20 at 16:40

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