Hi
I want to buy some wire at Radio Shack for a small project I am working on.
The project: 3 12 volt computer fans wire in parallel plugged into a portable 12volt power source. The circuit will have a switch and a potentiometer. The total length of the circuit will be about 3 feet at most. It is for outside use, in perhaps dewy conditions but not rain. What size, type of wire should I ask for?
Thanks
Bob Z
Some 18 AWG PVC-insulated wire should be more than adequate. We’re talking well under an amp of current draw.
There’s not enough information here to adequately answer.
Namely, what is the total power draw? Without knowing the current draw, there’s no way to guess. The resistance of the wires themselves (which decreases with increased radius) is also technically a factor in total power consumption (as it’s a factor in total current drawn), but not to the point of affecting anything.
The “safe” answer is to say use the thickest wire that’s easy to work with, but really, my hobbyist instict (read: as a BSECE student I have both hobbyist and technical insticts) is that 18-22 AWG would all be fine, and if you look online a bit, you should be able to find a recommended maximum current for the wires.
Just get something fairly small and stranded (as opposed to solid). If the wire is too big, you’ll have trouble attaching it to the switch and potentiometer.
You might also want to pick up some heatshrink to protect the connections from the elements.
I would use a regular duty, outdoor-rated extension cord (120 VAC/16 AWG) for the wires. (Just cut the plug off, cut it to length, strip back the outer jacket on each end, and strip each wire.) This is because the outer jacket is already rated for outdoor use (very durable, water proof, UV proof, etc.). The jacket also keeps the inner wires nicely bundled together.