How to determine wire gauge?

[lambda_epsilon]

Electronics newb needs to know what gauge wire to use... i have a prelit kit at home that looks like it may use like 22awg or something but i'm curious how you can properly figure out what you need. Example: my first home built kit will probably only include a max of 5 leds, a on/off switch, and maybe a dimmer. Nice and simple... Thanks for your help!

[Sparky]

I'll look through my handbooks at home, I picked up the electronics/electricians handbook while in school.

The answer
It has to do with current draw, the voltage, and absolute length of the wire. It boils down to the accumulitive resistance of the wire. How much voltage you loose across the wire is= Total Resistance * total current draw.

And whether the wire will burn-up is a mater of the power lost in the wire (as heat):
Total current squared * Total resistance
This is the power the wire is dissipating as heat.

[DLMatthys]

Electronics newb needs to know what gauge wire to use...

I favor ribbon cables to make wire harnesses to run in pairs throughout the model. I use some from discarded computer cable. Thier gage is adequate for using it to power LEDs and simple circuits.

http://www.culttvman2.com/dnn/Portals/0 ... entC10.jpg

Another good wire I like to use is hook up wire used in model railroading. If a local hobbyshop with trains is near you look for the wire spools with the Model Power lable. Spools come single, pair, and quadruple.

[lambda_epsilon]

Hmmm, that's an ingenious idea... wish i woulda held onto all those ide cables over the years... computer nerd here so i've seen a fair share of em.

[raist3001]

Computer geek here as well.

I use Cat 5 cable since I have a never ending supply of it.

[Sparky]

Going by this website:
http://www.interfacebus.com/Copper_Wire_AWG_SIze.html



Its all about how much wire you end up looping around inside. You don't want LEDs wired close to the supply to be brighter than ones further down the line, and you don't want to draw to much power through the wire as heat will increase the wire's resistance thus increasing the heat it generates (it becomes a vicious cycle) and reducing the power delivered to LEDs down the line.[/url]

[drache]

Hey Don, I picked up some of that Model Power wire. boy it's thin stuff, this is really good enough for LEDs? Thanks.