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Forum Index : Microcontroller and PC projects : Fake Copper Wire
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Geoffg Guru  Joined: 06/06/2011 Location: AustraliaPosts: 3194 |
This guy discovered that the wire used in some test leads that he purchased was in fact just iron coated in copper: https://youtu.be/15sMogK3vTI This led me to go on a hunt through my workshop with a magnet and I also found some fake copper wires. This is the problem with buying stuff from China, they can make it as cheap as you want... both in price and quality. Geoff Geoff Graham - http://geoffg.net |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 453 |
Thanks for the heads up Geoff. I have a stack of those clip leads in my shed too. I will get my magnet and see if they are real copper or not. It is getting hard to trust sellers these days. Pete |
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| Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 453 |
Back again, I checked some I have in the shed, Yep who would have thought that copper was magnetic. Some of my older ones don't respond to a magnet but the last batch I bought stick well and the magnet can pick up the lead no problems. The clips are also steel Pete |
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SimpleSafeName Guru Joined: 28/07/2019 Location: United StatesPosts: 319 |
I've known, and have not been bothered by fake copper wire for ages. The speakers in my local Radio Shack (yes we still have one as well as a drive in theater) have been waaay too light to be wound with copper for years now. My theory is that China switched to copper-clad steel because the weight of copper-clad aluminum is a dead giveaway to it being "fake" copper wire. Now they just have to create a market for defective magnets to get back to fooling their customers. Is any of this likely to affect the average hobbyist? Probably not. |
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palcal Guru Joined: 12/10/2011 Location: AustraliaPosts: 1873 |
The majority of my components have plated steel pigtails and because I live near the ocean they corrode. I have to keep them all in sealed plastic bags in my parts drawers and still they corrode over time. I also dabble in vintage radio and have sets 80 years old and the components with plated copper pigtails are still OK, no corrosion. "It is better to be ignorant and ask a stupid question than to be plain Stupid and not ask at all" |
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| EDNEDN Senior Member  Joined: 18/02/2023 Location: United StatesPosts: 117 |
If the steel wires have a thin coating of copper around the entire wire and the entire length of the wire... I would think it should be OK. The 'Skin Effect' ensures the vast majority of any current flow is on the very surface of the wire. And the metal inside the wire is basically a Faraday Cage where no electric fields (or current) exist. But the Chinese do anything to cut corners and who knows if they did a proper job coating the wire with copper. Who knows if they even used copper or something that kind of looks like copper. I haven't bought wire or test leads from the Chinese. But I have bought flash drives and SD Memory cards from them. And pretty much they all were fake. You are best off avoiding Chinese vendors for anything you care about. |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6089 |
Skin effect is for AC and increases with frequency. With DC there is negligible shin effect. VK7JH MMedit MMBasic Help |
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| EDNEDN Senior Member Joined: 18/02/2023 Location: United StatesPosts: 117 |
Yes. But two things to factor in. First, not many people watch DC signals on their oscilloscopes. And even if they do, the high input impedance of the scope means the super thin copper coating can conduct plenty of current to the test equipment so it doesn't degrade the signal very much. That is the explanation for why they get away with what they are doing. My experience with Chinese equipment is pretty negative. I feel I'm better off buying Western equipment. Edited 2024-11-15 14:42 by EDNEDN |
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| SimpleSafeName Guru Joined: 28/07/2019 Location: United StatesPosts: 319 |
We had corrosion problems with our stainless steel in Okinawa. So, yeah. I would be more concerned with the service lifespan of the wire in an application where the wires have to bend. Robot wiring harnesses for example. |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2129 |
Re bending life, it varies greatly depending on the composition of the steel. Some grades are better than copper. The effect of plating on skin effect is complicated. Early radar receivers often used silver plated wire, assuming that as silver is a better conductor than copper and most of the RF current is near the surface, it would reduce the resistance. When someone got around to measuring the difference the silver plated wire was slightly worse than plain copper. The boundary between dissimilar metals messes things up so unless the silver is so thick that almost all the current flows in it it isn't worth while. Something similar might apply to thinly copper plated steel. In any case using fatter wire should negate most problems. |
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| SimpleSafeName Guru Joined: 28/07/2019 Location: United StatesPosts: 319 |
As well as the thickness and the number of strands in a cable. The stuff that is used for high-end slot cars is mind-boggling. For example: Daburn "Daflex" 2618/16 is a 16AWG wire with 665 strands of 44 gauge copper. The jacket material, the non-conducting core, and even talcum powder between the jacket and the wire also make a difference. |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4213 |
Oops... That may explain issues I had recently. With both test leads, and now I suspect USB-C charging cables, that cause all kinds of problems with my wifes phone. I'll pull out a magnet today. And take it with me to the shop when I buy a new cable. Volhout PicomiteVGA PETSCII ROBOTS |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6760 |
The main problem is the cost of copper. It's very expensive now. If you need to keep costs down to be competitive then plated steel is the way to go. Here in the UK our 1p and 2p coins have all been copper plated steel since 1992. From an electronic point of view very few wires are run at full capacity - and steel, although not as conductive as copper, isn't too bad. Providing the plating is thick enough to allow proper soldering things are generally fine. IDC connectors don't matter as they form a gas tight connection anyway (telephone systems use a lot of plated wire). The main problem with pated wire is long term corrosion, but if the connections are good and the wire isn't being flexed appreciably it's usually ok in most circumstances. We used to install copper plated aluminium busbars (trade name Cuponal) in switchgear. The skin effect at 50Hz is almost negligible but the reduction in cost over "pure" copper (they never are - it's too soft) busbars was appreciable. The copper plating was there to ensure a good connection when jointing. You couldn't just drill and bolt it as that exposed the copper-aluminium junction to the air, which eventually degraded the joint. Busbar clamps were always used for this stuff. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3797 |
I've had wires with the usual insulating outer layer but the core is stranded (something: plastic? thread?) and extremely thin stranded metal. I hadn't thought to try a magnet :( John Edited 2024-11-15 19:08 by JohnS |
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| SimpleSafeName Guru Joined: 28/07/2019 Location: United StatesPosts: 319 |
Our pennies are copper-plated zinc. Or "scrap metal" as I like to call them. We ran aluminum feeders to every house, as well as some commercial buildings. And the electric stoves in houses would always use aluminum as well. No problems whatsoever as long as it was done right. It's when knuckleheads would use a brass split bolt to make aluminum connections. Usually several inches of insulation would be burned off before we were called out to fix it. Or if they mixed copper and aluminum together in a non-rated connection (AL-CU). If you look in a panel, the busbars are almost all aluminum-esque (not sure what they are made of, but it ain't copper). Maybe Square D is the exception, I don't know. |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4213 |
Hi, Aluminum is fine, it is only 1.5x higher resistance. Iron is bad, it is 6-7x the resistance of copper.  Volhout PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6760 |
As I said though, it's actually quite unusual to be running wires at their maximum capacity - at least not continuously. Copper plated steel, providing the copper plating is reasonable and the length isn't long, will usually be fine. Certainly at an amp or two. You'll get a little more volt drop but most gear won't notice. There are cases where you need copper conductors of course, test gear being one. The wiring has to be reliable and temperature stable. High current busbars are another case, especially where there may be a high ambient or a corrosive atmosphere (they are often tinned in that case). Silver, although an excellent conductor, is generally rubbish. Precision resistors used to have silver plated copper leads which usually blackened in storage to the point where they wouldn't tin. It's not good stuff for electronic work as you need a much hotter soldering iron and special solder. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| SimpleSafeName Guru Joined: 28/07/2019 Location: United StatesPosts: 319 |
That (we have to limit our circuits to 80% of full capacity), and should it find it's way into the North American National Electric Code, it will get its own column in the ampacity table. Right next to baling and barbed wire. Chewing gum will also be added as another insulation type. What's interesting is that the new (potential) record holder for "high temperature" super-conductor is iron. I don't think that it has happened as of yet. But it's projected to work at -98C. |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4213 |
Sorry, disagree When you have a USB charger, and charge a phone, the phone will determine (by voltage drop) what the charger is capable of. With 2 x 300 mohm (as in the movie), it will decide to charge at 100mA. Regardless this is a 3A charger. An I-phone will even decide to NOT charge at all, since it decides this is no Apple-made charger or cable. Been there, done it. Have throuwn away several cables already. Volhout Edited 2024-11-15 20:15 by Volhout PicomiteVGA PETSCII ROBOTS |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6760 |
Oh yeah, there are *really bad* cables, where the copper coating (I won't call it plating as I don't believe it is) may as well not be there. They are resistive and unsolderable, usually. If you look at how they are connected to the PCB in the charger it's either a nasty blobby mess or there are brass ferrules crimped on before soldering - the plug end is crimped. I wouldn't accept whether an iPhone will accept a charger as a valid test. Sometimes they appear to refuse official Apple leads from what I've been told! They don't read the D+ and D- bias resistors in what has become the standard way to read the charger capabilities. I have a diagram somewhere that shows the bias values to use. USB-C has a different system. For *really* rubbish cables look at the USB leads for printers. Most of them are remarkably poor because they are only intended to carry a couple of mA. The 5V core too, as the printer will provide its own power. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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