What kind of wire is this?

[TigerhawkT3]

I just cut this wire open to put an extension in the middle. However, I can't find any conductive parts. :duh2:



The white part feels fibrous, like some sort of cloth, and the dark strands feel like ordinary wire (but I get no continuity). Could the conductive part simply be inaccessible to my DMM probes? I might try cutting off a short piece and tinning both ends to see if I get continuity between them.

 

[monkeyboy]

Perhaps the dark strands have a layer of insulation that also needs to be stripped and the white part is some sort of dielectric shielding or just there for strength?

Just a guess.

 

[darkzero]

What's it from? Reminds me of a headphone cable. The cable appears to be for signal transfer & not for power use.

 

[greenLED]

Could the ordinary wire in there be coated?

 

[TigerhawkT3]

What's it from? Reminds me of a headphone cable. The cable appears to be for signal transfer & not for power use.

Bingo. It's from a little wired remote for the Cowon A2. I got it to be able to pause/volume/etc. from the couch while feeding video to the TV, but it's three-pin (tip and two rings instead of just tip and ring), so an ordinary stereo headphone extension cable won't work (I tried).

Looking at the other macro shots I took, it looks like the dark strands have a lighter dot at their shorn tips. That might indeed mean that the dark strands are individually insulated wires. I think I'll have a go at tinning them to see if I get continuity.

Thanks, all.

 

[DonShock]

These are probably insulated with a varnish type coating. YOu'll have to try to scrape off the insulating varnish before you can tin and solder on extension wires. It's a pain to try to scrape off the varnish and leave the tiny wires intact, Good Luck!

 

[TigerhawkT3]

Do you think the varnish could be melted off without damaging the conductive part?

 

[greenLED]

Just scrape it off (*very* gently) with an exacto knife. I think last time I did that I bundled the wires and scraped them all at once. It didn't get all the goo off, but I didn't cut the wires either.
Good luck.

 

[PhotonWrangler]

You could also try (carefully!) burning the varnish off with a match. Or grab some sandpaper and take it off that way.

 

[KC2IXE]

Looks like you have some sort of Litz wire - used for very high frequencies, to combat "skin effect" - basically a bunch of twisted or abraded insulated wires,, wrapped by a protective layer

The individual strands will be varnish coated. In industry, there are two standard ways for stripping the strands. One is a rotary stripper that has 2 rolls of what look to be a porous eraser, they spin fairly fast, and are lightly spring loaded against each other - you feed the wire in, and when you pull it out, it has abraded the varnish off - works well, fairly expensive, but pretty much the way to go in production with strands above say, 20 gage or so (below that, it tends to break the wires)

similar to
http://www.eraser.com/catalog.cgi?mode=details&product_id=1402

The OTHER main method is chemical, and gad if I can remember the name of the stuff - I remember it was a mix of Meth chloride, acid, and some other "stuff" - you would dip the wire in it, wait 2-3 minutes, and wipe the insulation off with a paper towel, and then WASH the wire to prevent corosion - digging around, it seems it was called "strip-x", and worked quite well

here is what I can find

http://newsgroups.derkeiler.com/Archive/Rec/rec.radio.amateur.homebrew/2006-02/msg00180.html

 

[TigerhawkT3]

Success! Waving the wire ends through a match-like flame burned off the white insulation (or whatever it is) as well as the varnish. I crimped and soldered the ends into Molex-type connectors, and it all works. I'm kind of surprised, really - pleased, but surprised. Thanks, all!

 

[LukeA]

I wish I would have seen this earlier.

I fixed a headphone cord a few weeks ago. The inside of it looked exactly like this (except the wire was colored for channels and stranded). I just fluxed the wire and held the iron on it and the coating dissolved and left me bare copper. I had had my fingers crossed for that to happen.

 

[PhotonWrangler]

Success! Waving the wire ends through a match-like flame burned off the white insulation (or whatever it is) as well as the varnish. I crimped and soldered the ends into Molex-type connectors, and it all works. I'm kind of surprised, really - pleased, but surprised. Thanks, all!

Woo-hoo! Combustion can be our friend sometimes.