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OT, Crazy "springy copper" electric cord wire

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  • OT, Crazy "springy copper" electric cord wire

    So, the plug on the CAD computer (Dell laptop) power supply cord had the insulation crack right at the plug. The cord was one with the clover-leaf end on it, not the standard 15A rectangular IEC end that is common these days, so I did not have a spare handy.

    I strip the wire and start to put a new plug on it.

    Well, the wire is very small gauge, stranded. That in itself is not an issue. But I needed to twist the strands to form a tight bundle.

    Surprise! They cannot be twisted! All the twisting I did, resulted in them simply springing a little farther apart. They WOULD NOT twist.

    Next I tried doubling them back to form a thicker bundle. THE STRANDS WOULD NOT BEND! At least they would spring over, but straightened as soon as they were released. I finally completely doubled them over, and crimped the bend. At that point they would spring back to a 90 deg angle.

    I've never seen anything as springy as these, I'd swear they were made of phosphor bronze, and not copper. (I checked with a magnet and no, they are not copper plated steel).

    Anyone ever seen hat before? It was a first for me.
    1601

    Keep eye on ball.
    Hashim Khan

  • #2
    Titanium wire? (kidding)

    -D
    DZER

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    • #3
      Yep.

      Copper wire produced in the third world is drawn without being annealed.

      My first experience with installing UPS units in Pakistan led to importing North American manufactured wire for subsequent installations.

      Comment


      • #4
        Originally posted by bob_s View Post
        Yep.

        Copper wire produced in the third world is drawn without being annealed.

        ....
        This stuff is hard enough to bend that a person can understand making knives out of it. But I think it has to be an alloy, its harder than I have ever seen work-hardened copper, and much springier. Odd.
        1601

        Keep eye on ball.
        Hashim Khan

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        • #5
          May be litz wire, almost impossible to work with without special tools and connectors.
          https://en.wikipedia.org/wiki/Litz_wire

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          • #6
            I remember helping a buddy a few years ago set up a ham radio station, he had something along the lines of what you have.

            https://www.tetemtron.com.au/1-63mm-...e-hdcw1.63.htm

            Can't figure out why it would be used in an application like a supply cord though???
            Home, down in the valley behind the Red Angus
            Bad Decisions Make Good Stories​

            Location: British Columbia

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            • #7
              In NA and EUR copper is smelted to 99% purity for the purpose of making wire.
              If wire is being made from recycled materials there may be considerable fractions of zinc, iron, tin, aluminum, sulfur,... all of which lead to much less ductile alloys/mixtures.

              Try annealing a sample. If it turns a bluish color at the cool end, you can bet your bottom buck that it contains either/or both iron and nickel.
              Last edited by bob_s; 08-22-2017, 02:02 PM. Reason: last line

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              • #8
                Have you tried the magnet test? Very low current they could easily expect to get away with copper plated steel. Didn't something similar come up last year?

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                • #9
                  Yes, its not the wire but the application that seems odd. In the old days, all the cheapo 'earphones' (what we now call earbuds), used a similar wire. Those strands were flat, though, and were nearly impossible to twist and/or solder.

                  Some time ago, someone (Evan, maybe) posted about buying some heavy gauge speaker wire only to have it snag on a magnet on the way out. Sure enough it was copper plated steel wire advertised as 'copper'. From China of course.

                  Oops, I see Baz types a lot faster than I do!

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                  • #10
                    I had already checked with magnet.... not the issue.
                    1601

                    Keep eye on ball.
                    Hashim Khan

                    Comment


                    • #11
                      Old style headphones and headsets had a very flexible cord with wires that were stiff, hard to work with, and hard to solder. I always thought they were steel plated copper but I have no evidence to that effect. Now I wonder what they really were.
                      Paul A.
                      SE Texas

                      Make it fit.
                      You can't win and there is a penalty for trying!

                      Comment


                      • #12
                        I've run into that issue a few times, always managed a work-around by heating the wire (Hemo's clipped above the working area while applying heat). Can't say anything for durability because I always said f it and replaced the next time they broke without checking out why.

                        The thing I run into most often lately is wire that looks like 12 gauge, but when I have to perform a repair and cut away the insulation I find that the actual wire itself is maybe 18 or 20 gauge.

                        J tiers post reminds me a lot of trying to work on the wiring on late 70s/early 80s GMs, not sure what the heck they used for wire, but was almost impossible to repair without entirely replacing the wire.

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                        • #13
                          I got irritated, dug into some old boxes, and found a cord with the "cloverleaf" IEC connector on it, so the immediate issue is gone.

                          That wire is REALLY springy... maybe it's hard-drawn, but.... it appears to be maybe 22 GA, or smaller, with a dozen or more strands, so the individual strands are very thin. The wire was so thin as a bundle, that the clamp type plug screws would not even hold it.

                          If I WANTED wire that springy, I bet I;d have a hard time finding it. Maybe I should keep the remains of the cord, so I have a supply (for what reason I might want it, I cannot explain).
                          1601

                          Keep eye on ball.
                          Hashim Khan

                          Comment


                          • #14
                            Makes me wonder if the strands are coated with something- perhaps nylon. I've had a few instances where the strands resist twisting together, and didn't solder worth a damn either.
                            I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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                            • #15
                              It might be worthwhile to check the resistance of the wire. If you don't have a DLRO, put one or two amps through it and check the voltage drop. It's probably not phosphor bronze or beryllium copper, since they are expensive, but perhaps an alloy of various recycled metals that has such stiffness and spring.

                              Beryllium copper is probably most likely, however:
                              http://www.ngk.co.jp/english/product...umcopper/wire/
                              http://pauleschoen.com/pix/PM08_P76_P54.png
                              Paul , P S Technology, Inc. and MrTibbs
                              USA Maryland 21030

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