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Author Topic: What is best - or smallest sized wire I can use for LEDs  (Read 658 times)
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Im at Jameco.com right now, and they have 18awg for $13.95 100 ft and they have 22 awg for $7.95

Naturally I would go with the lower priced..but can i get away with this.
Im actually going to only need to power a string of about 10 5mm LEDs on each circuit for the entire night during the holidays.

Would the 22 awg be okay?

Im going to use speaker wire for the main lighting.
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Hi,  i've routinely used ribbon cable for driving LEDs which are 22awg or thinner without issue.
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It's all about current --

http://www.cablesandconnectors.com/wiregauge.html

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22AWG shouldn't present any issues in short runs for 1-3 standard 20mA LEDs in parallel.
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I use 30 guage wirewrap wire on boards, no problem for strings of 5 LEDs from 12V.
You have 10 LEDs, 24V, but still just 20mA? Any stranded wire above 30 for some flexibility in setting up the layout without breaking single strands would be fine.
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It also all depends on the length of the wire!

rule 1:  don't exceed the current rating of the wire (else it will overheat).

rule 2: for long runs calculate the maximum total resistance your circuit can tolerate and choose wire thick enough
            that the total resistance is at/below your maximum.  There are numerous tables of resistance-per-unit-length available.
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Im at Jameco.com right now, and they have 18awg for $13.95 100 ft and they have 22 awg for $7.95

Naturally I would go with the lower priced..but can i get away with this.
Im actually going to only need to power a string of about 10 5mm LEDs on each circuit for the entire night during the holidays.

Would the 22 awg be okay?

It all depends on how long the wire is.

Voltage will drop as it goes along the wire. Will there be enough left for the LEDs at the other end? That depends on the distance and how much excess voltage you had at the power supply.

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Guys, Relax.
#18 is about 6 ohms per 1000 feet.
#22 is about 16 ohms per 1000 feet.
#28 is about 65 ohms per 1000 feet, over a 100 (!) foot run that would be 6Ω.

(1000 feet = 305 metres.)
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Guys - we're talking about an arduino wiring/breadboard - not a house circuit.
It will only be 1 foot at most.

So perhaps I should rephrase my question more precisely.
If, Im going to do short runs of at most a few feet from the controller, can I get away with 22 gauge wire?

Shouldnt I be able to use pretty much any wire that can handle the ampacity for 5 little bitty LED's?
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Yes, 30 guage wirewrap wire for a breadboard carrying 20mA to an LED.
22 is overkill.
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perhaps I should rephrase my question more precisely.

That always helps.

If, Im going to do short runs of at most a few feet from the controller, can I get away with 22 gauge wire?

Shouldnt I be able to use pretty much any wire that can handle the ampacity for 5 little bitty LED's?

For 5mm, 20mA LEDs? No problem. Use anything.

I run 1W LEDs (350mA) on 33 gauge wire over a couple of feet. I wanted wire that was almost invisible for some hanging lamps and I had some 33 gauge magnet wire handy so I gave it a try.

I lose about half a volt due to resistance in the wire, that's 0.5V x .350mA = 0.175W power loss. One-sixth of a watt spread over four feet of wire doesn't even make it warm to the touch. All I need to do is make sure the power supply has 0.5V more than the LEDs need to compensate the loss.

PS: According to the Internet, 33 gauge copper wire melts at 29 amps smiley

« Last Edit: March 26, 2013, 05:56:09 am by fungus » Logged

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Thanks everyone for the very useful information.
Its hard starting out at first, so appreciate the time and effort you guys have been extending me to help me on my way.
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