I'm building a modular art installation consisting of multiple 1 meter LED bars. From the power supply / microcontroller there are multiple lines consisting of 2 - 6 bars.

The LED strips I got need power injection at least every 4 bars.

Generally, Option A (see attachment) would be the way to go. However, the hassle of an additional power cable after 4 bars is not desired. I would like to have the freedom of having 1, 4, or 6 bars without any additional cables.

So I came up with option B: internal cabling. However after reading this I'm doubtful. Why would option C be better? Or is there a better option than B and C?

Since all bars need to be the same I suppose the 'internal bypass cable' (like as in option B/C) needs to be at least the same calculated thickness as the 4 meter cable that comes before it, correct?

PS. Yes, I know I need some juicy wires to power them all on full white.

wiring schematic

  • \$\begingroup\$ For inexpensive large size wire, don't forget wires intended for AC power distribution such as twin-and-earth or THHN. If in North America, alumimum is also on the table but requires special terminations. \$\endgroup\$ May 1, 2022 at 17:47
  • \$\begingroup\$ In your diagram, you show B as having both ends of each LED strip being attached to your power source, as well as a "bypass cable" around each. What benefit are you hoping to gain from the second connection to power bus on each unit? \$\endgroup\$ Nov 18, 2022 at 16:36

1 Answer 1


C would be ideal, b second, and A the minimum for a decent installation.

C provides a low resistance to both sides of the bars, which means the far end of the bar doesn't see a voltage droop from high current draw over high resistance FPC. If it uses FPC and not appropriately sized pcb.

But at 1M per bar, the voltage droop is unlikely. Unless they are cheaping out on the copper pour it should be fine to only power one side. B is a nice middle ground in efficiency vs cost.

A is probably okay too since that's what's recommended. It all depends on the cable size and the current draw. The size of the cable in any case requires an analysis of Max Current Draw vs cable length/resistance.

Typical RGB led strip rule of thumb is inject power at every 2.5 Meters or 5 Meters depending on how thrifty you may be. So injecting at 4 Meters means your halfway between the rule already.

  • \$\begingroup\$ Thanks! Wouldn't 'B' be daisy-chaining and therefore bad practice? Source (perhaps creating a 'groud loop'? ) \$\endgroup\$
    – Mark
    May 2, 2022 at 10:18

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