2 conductor round cable source?

[kuksul08]

Does anyone know where I can find some cable that must have the following features:

-round (preferrably molded)
-two conductor (18Ga preferred)
-available in low quantities (by the foot or <100ft spool)
-flexible
-outside diameter <0.20"

Most cable i find is either two side by side which is more rectangular and tangles easily, or multiple conductors wrapped in a sheath that has ridges and bumps along its length. Think of something like a USB mouse/keyboard cable except with only 2 wires.

I've searched a LOT for this and it's very hard without seeing the cable in person. TIA for any help.

 

[Lobstradomus]

I know I've seen thermostat wire that fits all of your criteria aside from the fact that it has 3 conductors, never seen it with just two. It sounds to me like what you are ultimately looking for is a twisted pair style of speaker wire and you might have some luck with that at a car audio or home entertainment type store. The only other cheap and abundant option I can think of is stripping down some cat5 cable and using the twisted pairs within, although those are smaller than 18 awg (24 IIRC.)

 

[kuksul08]

I know I've seen thermostat wire that fits all of your criteria aside from the fact that it has 3 conductors, never seen it with just two. It sounds to me like what you are ultimately looking for is a twisted pair style of speaker wire and you might have some luck with that at a car audio or home entertainment type store. The only other cheap and abundant option I can think of is stripping down some cat5 cable and using the twisted pairs within, although those are smaller than 18 awg (24 IIRC.)

I just tried looking at some speaker cable, it looks like most is either nylon sheathed or two side-by-side. I have a lot of CAT5, but 24Ga is too small for power transmission I think. I'm trying to minimize resistance for a cable will be carrying up to 2.8A for up to 5 feet one way. (24Ga = 0.25670 Ohm/10ft = 0.72V drop, 18Ga = 0.06385 Ohm/10ft = 0.18V drop)

 

[yazovyet]

Thats a long way to run wire and I can't imagine that all being in a flashlight. Can you use a larger wire to run most of that distance then switch to a smaller one for that last bit to the driver or heatsink?

 

[kuksul08]

That's essentially what I'm doing. In the light housing there are only a few inches of 22ga wire, but the battery pack is remotely located with up to 5 feet of cable.

 

[jeffosborne]

I like to re-use old notebook computer power supply cords. Not the cord that goes from the AC outlet to the adapter, but the cord that goes from the adapter to the computer. It is often 6', always round, heavy gauge, coaxial wire. And usually very flexible due to having many strands of fine wire. Go to your local computer store and ask them if they have any failed notebook power supplies heading for the dumpster. I salvage mine at the office when they go bad.

Jeff

 

[DFiorentino]

I <3 McMaster Carr...they've got everything.

Search for 71335K57 as an example.

-DF

 

[kuksul08]

I like the notebook power cable idea!!!

And thanks^ I am going to buy some 1ft pieces of a few types to try out.

 

[CKOD]

Assuming you want round to work with a cable gland for waterproofing and outdoors use, I would check out using 'SJOOW' cord, its more rugged with a neoprene jacket than a plenum cable would be with a pvc jacket. Home depot may have it too if youre lucky.

7422K2 on mcmater for black jacketed 8042K11 for yellow jacketed

 

[kuksul08]

Thanks for the tip^ I want round because it will fit in a water proof bushing and seal properly. It will be used on portable outdoor light (bicycle, work light, etc)

What do you know, I asked the IT guy and found a busted HP laptop power supply today. I cut off the DC side power cable and it was a nice black, high strand count coaxial cable. I'm wondering if coaxial (18AWG center, copper braided outer) is as good for power transmission as two normal wires. I also can see why the power supply failed... the braided outer conductor near each end was fatigued and broken into little bits.