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I have recently started to learn about electronics and as my first project, I'm trying to make a wifi-enabled LED strip.

I have read a lot about all the theory, followed tutorials, and try to be extra careful because well, toying with electrical stuff can be dangerous.

I don't know what to use to make electrical schematics but I took photos of my design and I would feel a lot safer having some feedback from experienced electrical engineers, especially about my chosen wire size (details below).

Here is some information:

  • Power supply: 5V, 3 amps (max).
  • LEDs: WS2812B (20 leds separated in 5 groups of 4, each connected through).
  • Controller: NodeMCU
  • 26 AWG silicon wires for connecting the LED strips together and also the power supply to the first LED strip.

Here is an overview of the thing:

enter image description here

And here is a close-up of the board, top and bottom (my soldering skills still need improvement, there is no doubt):

enter image description here enter image description here

Now my main concern here is:

Is my chosen wire size (26 AWG) adequate for such sustained full LED brightness activity?

From my calculations, LED at full brightness (full white) should draw a maximum of 60 mA each, so 1200 mA for my 20 LEDs. I've let that design run at full brightness for an hour now, trying to see if things get hot and so far, it doesn't seem to be the case. But that's hardly a guarantee, especially as I plan to put the PC in a plastic casing in the future, so I assume heat will dissipate even less.

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  • \$\begingroup\$ Did you, um, try searching current rating of 26awg wire? \$\endgroup\$ – Brian Drummond Mar 8 at 15:32
  • \$\begingroup\$ Does the wire get warm. Dont you have a DMM yet> \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 8 at 15:33
  • \$\begingroup\$ Depends on how long the cables are: powerstream.com/Wire_Size.htm \$\endgroup\$ – Peter Smith Mar 8 at 15:33
  • \$\begingroup\$ @BrianDrummond Yes. But then I find a lot of different tables with a lot of contradictory numbers and I have no clue what to make of those. I'd rather ask people with more experience than let my pride cause a fire. \$\endgroup\$ – ereOn Mar 8 at 15:38
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    \$\begingroup\$ sure a lot of wires for wireless ;) \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 8 at 16:30
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So far OK for power.

Since each 5V RGB LED has much more onboard Resistors than a short span of light gauge wire, the loss is small until you cascade much more than what you show. i.e. whatever causes the voltage across bus to drop below 3.5V

  • Short strips are OK, but not 5 meters.

  • You can estimate the loss from each wire Power and ground from AWG tables Ohms/meter * AMps = Volts (x2 for PWr and gnd)

  • AWG 26 =133.8 Ohms /km or mOhms/m = 0.134 Ω/m

    • 0.134 Ω/m * 3A max *2 (pwr+gnd) = 0.8V /m so 1 meter is tolerable dropping 5 to 4.2 but then LEDs use 3.4V multiplex'd * modulated for brightness

WS2812B specs Power supply voltage VDD = +3.5 ~ +5.3 V

So still regulated ok on 1m with 4.2V maybe 2m wire would work but then we get into EMI interference issues with data errors from unknown interference poor grounding. COM ERRORS.

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  • \$\begingroup\$ I have 10 (cables) * 2 (PWr + gnd) * 17cm = 340 cm total 26 AWG cable. So... far below the 1m mark. I do not intend to add any more strips as 5 of those 4-LEDs strips light more than enough for my needs. Thank you so much for the answer as well as the detailed explanation. I'll definitely consider AWG beforehand for my next project. \$\endgroup\$ – ereOn Mar 9 at 1:16
  • \$\begingroup\$ great. I wish I understood what advantage I can have with your VPN. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 9 at 1:24

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