[SOLVED] Does wire thicknesses play a role?

Hello everyone!

I just wanted to ask, if the wire thickness does play a role when using an Arduino. I just soldered some other parts and now I wanted to solder the wiring and I am not sure, if the wires I am using are thick enough or if I can neglect the thickness of the wires. I wanted to use these “standard” grey cables. I attached a photo. They should be analog Input cables for ldr’s connected to 5 kOhm resistors to the arduino of course with a voltage divider. I also want to use them for digital output for green LEDs with 150 Ohm resistors.

They got 28 AWG. Is that enough?

The short answer is no, it usually doesn't matter. At higher currents (higher amperage) or with lower resistance circuits it can be an issue.

Wire does have some resistance and the smaller diameter and/or longer the wire, the higher resistance. [u]Here is a chart[/u] and it shows that 1000 ft of 28AWG wire has about 65 Ohms of resistance.

[u]Here is another chart[/u] showing recommend maximum current for different gauges and different insulation. You get a voltage drop proportional to current and inversely proportional to resistance ([u]Ohm's Law[/u]), and the power lost in the wire generates head (which explains the different ratings for different insulation).

Sometimes there is a voltage drop across the conductors in a long LED strip and the LEDs at the far-end are dim, they don't work. The solution is to run "fat" power & ground wires and connect the strip at both ends, and sometimes in the middle, etc.

For low current digital signals 28-30AWG wire is good enough.

#30 ‘solid’ wire wrap wire is a good choice, actually better than ribbon cable 28AWG stranded wire.

See this PDF:

Post #692

Thanks for the quick and helpful answers!