What wiring gauge for LEDs application?

Hi friends!

Probably it is a stupid question but I am really a total idiot in electronics!!!!

I have some projects with Arduino that will use only LEDs to light starship miniatures (windows, navigation, etc.).

I already have a small prototype that I just started working on:

Arduino prototype

My problem is that I don't know what gauge of wire I should use for the actual circuit. The LEDs will be soldered directly to the tip of the wires and these will reach the lighting places in a harness.

I have found a virtual store that sells plastic insulated wires in the following gauges: 0.05mm; 0.10mm; 0.13mm; 0.20mm; 0.30mm; 0.32mm; 0.50mm.

What would be the ideal gauge for such application? I thought on buy the thinner one (because LED has a low consuming and also because it's cheaper!) but better to ask first.

I will use also some high brightness white and blue LED tapes but these ones I will attach directly to the power supply (no arduino). What wire gauge in this case?

To give you an idea about the type of wiring I am talking about, here it is an example of a similar project:

Wiring sample

And here an example of the project after done:

Cool project

Thanks!

:)

Hi friends!

Probably it is a stupid question but I am really a total idiot in electronics!!!!

I have some projects with Arduino that will use only LEDs to light starship miniatures (windows, navigation, etc.).

I already have a small prototype that I just started working on:

Arduino prototype

My problem is that I don't know what gauge of wire I should use for the actual circuit. The LEDs will be soldered directly to the tip of the wires and these will reach the lighting places in a harness.

I have found a virtual store that sells plastic insulated wires in the following gauges: 0.05mm; 0.10mm; 0.13mm; 0.20mm; 0.30mm; 0.32mm; 0.50mm.

What would be the ideal gauge for such application? I thought on buy the thinner one (because LED has a low consuming and also because it's cheaper!) but better to ask first.

I will use also some high brightness white and blue LED tapes but these ones I will attach directly to the power supply (no arduino). What wire gauge in this case?

To give you an idea about the type of wiring I am talking about, here it is an example of a similar project:

Wiring sample

And here an example of the project after done:

Cool project

Thanks!

:)

99% of my Arduino projects use 26-24AWG stranded wiring. I use 22-20AWG if there is power needed at a distance ~1-2 feet (this obliviously depends on the current needed).

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Please don't cross post: http://forum.arduino.cc/index.php?topic=408882. This wastes people's time due to duplicated efforts answering your question.

Without knowing the LEDs you plan on using...

If you're going to do anything with electrons, then you should at least understand Ohm's Law, which is sort of the equivalent of the Ten Commandments for electrons.

Each LED has a fixed voltage drop when lit. But the LED basically has no resistance when lit. So if you just connect both sides of a power supply to the LED, poof!, no more LED. You must always put a resistor in sequence with the power to the LED and that is chosen by deciding how much current you will allow to go through the LED: more current, more brightness, and most LED's are safe with 20 - 30 ma., but above that level, you better check.

So, let's say I want to light a red LED with a natural voltage drop of 3.0 v., and I have a 5 v. power supply, and I would like to have 20 ma. flow through the LED. Then the LED, is offering effectively no resistance, and I must use enough resistance so that I get my 20 ma. current. If I put a resistor between the 5 v. supply and the LED, and I know that the LED has a 3 v. drop, the resistor is experiencing 2 v. across itself.

Here's where Ohm's Law comes in, V = I*R, which relates current, voltage, and resistance. Rewrite it as R = V/I, and in our case we have R = 2 v./0.02 amps = 100 ohms.

Now wires have resistance too, which varies linearly with wire length, but if you look up the resistance/foot, for almost any wires down to about 30 gauge, it won't have much effect, for small currents and short distances.

Nonetheless, I suggest you internalize Ohm's Law, and learn to read a wire gauge table, and over the long run, you'll contribute much less smoke to the atmosphere.

@NCC1966, please do not cross-post. Threads merged.

Every wire is a resistor, the same rules apply - calculate the resistance, calculate the power handling at the load current and check it won't get too hot. For most reasonable instances the resistance of the wire will be way way less than the current limiting resistor for the LED and can be ignored - except for the case of high power high current LEDs.

The resistance of a piece of copper wire is easy to calculate, resistivity of copper x length / area, all SI units. Resistivity of copper is about 1.68e-8

Hi, Don't over think this project.

You will only be using relative short runs, so a gauge the same as the leads of the LEDs will be enough. The power lead to the arduino can be heavier, but for the LEDs I have seen guys use the most physically suitable gauge that will allow the wires to be hidden.

Tom... :)