EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Mp3 on July 14, 2020, 05:29:34 am
-
The solid core wire I own isn't usable for the purposes I got it for, it has insanely low resistance and seems to just not work when using it for what I bought it for - repairing or making new traces especially on single-sided PCB's. (I used all the bus wire i had and now i am going through my silicone wire for this purpose)
Look at this picture for example, lots of small bus wire jumpers on a single sided PCB.
https://1.bp.blogspot.com/-mz829YFao6Y/Wv6izOwW_KI/AAAAAAAABlQ/ajz_amELqzwtMloM0k-xqV3lHkhd8Ip7wCEwYBhgL/s1600/IMG_4013.jpg
I was going to buy bus wire but I have heard a lot of talk in recent years about using enameled copper magnet wire instead. I have even bought some DIY kits that included this stuff instead of bus wire.
I have looked and looked and tried to find why one would use magnet wire instead of plain old bus wire, and i can't find a single discussion about it on Google.
Is it just because it seems to be cheaper? 200 feet of bus wire in 24awg on eBay seems to be $15 + shipping whereas 200 feet of 24awg enameled copper magnet wire is available from several sources around just under $8 shipped.
-
Enamel is insulation. Bus wire is not insulated.
If you don't need it to be insulated, tinned bus wire is fine and easier to solder because you don't have to mess about abrading or burning off the enamel.
Magnet wire is of course produced in vastly greater quantities (for inductors and transformers) than tinned bus wire (whichhas few uses other than for links on single sided boards), which I expect accounts for the difference in price.
-
I read OP's complaint few times and I cannot make heads or tails out of it.
What are you trying to do? Jump between points? Copper wire will of course have near zero resistance. That's how it should be. If you don't want zero resistance, then you'd use registers instead of copper wires.
As someone else has already said, bus wire is typically a plated copper wire. Magnet wire is enameled or some other insulating material coated copper wire. Some melt with soldering iron and most don't.
Will you revisit your question and clarify what you want to do?
-
I think the poster meant thermal resistance, not electrical resistance, that is to say, his solid core wire's insulation melts too readily when soldering probably (hence them using silicone wire instead).
-
The terms are a bit messed up and used incorrectly sometimes.
But magnet or transformer wire is usually intended for higher temperature applications. Like the center of a transformer or electromagnet :) which can get pretty hot. Because of this it's usually hard to remove the insulated coating from this wire, you typically have to physically scrap or sand it off which is quite annoying. Other types of insulated wire can sometimes be burnt off with the soldering iron or a flame, which is much easier to work with.
Enameled copper wire is more a generic term.
Bus wire, as already stated, is not insulated so is quite different stuff.
You really have to read the datasheet to know what you're ordering. just going by the name will usually come back to bite you.
I use ROADRUNNER wire from element14 for my PCB reworks, the coating melts off nicely using the soldering iron. It's pretty thin wire, like 32AWG. I think you can get a few sizes but they are all pretty tiny. Good for QFN / 0402 style rework.
-
I saw some shops selling enameled magnet wire as suitable in place of hook up wire. I had no problem using the stuff I got in a DIY kit to use as jumper wire. I never would have considered using it instead of bus wire anyway.
I wasn't able to find out exactly what it was from the company that sent it. It soldered fine and worked fine, so i was mainly curious if there is some reason i would later come to regret using it in place of plain bus wire. So long as it's the kind that can be soldered / have its enamel melted with plain solder, it shouldn't have any negative effect is what i'm understanding, plus it seems i could use it in place of hookup wire where insulation is necessary.
(https://www.temcoindustrial.com/media/static/products/ebayupload/MW0195_01.jpg)
-
https://hackaday.com/2020/03/09/dont-scrape-magnet-wire-do-this-instead/
-
There are different insulations ("enamels") for magnet wire. Some, such as "Beldsol" will melt off at a soldering temperature of 750 F = 400 C, but are only rated to 132 C service temperature. On the same page, "Poly-thermaleze" is rated up to 180 C service temperature, but require mechanical stripping (a pain). When we used "Beldsol", we kept a small electric solder pot on the bench with SN60 solder: the enamel would float to the surface.
See: https://www.alliedelec.com/m/d/8139cfad1f463823b23dca2e068bc5fc.pdf (https://www.alliedelec.com/m/d/8139cfad1f463823b23dca2e068bc5fc.pdf)
-
The easiest way I've found to get these short pieces of bus wire I need is to just strip the insulation off some piece of tinned solid copper hookup wire that I have plenty of. Until removed the insulation prevents any oxidation of the wire so it will be clean and solder easily.
-
For short runs on PCBs I use silver plated copper wire from the craft store,
More expensive but solders like a dream.
Wally
-
dont let the leads on through hole components ping across the workshop when trimming them,keep them for pcb short links
-
The main reason people use enamelled wire for repairing pcb traces is that it's available in very fine sizes, which is a good thing in this day of traces that you need a microscope to see.
If the work you're doing doesn't need anything that fine, there's no particular reason to use enamelled wire.
-
If you need very fine wire, but don't want the hassle of removing enamel, you can unstrand stranded copper or tinned-copper stranded wire to get short pieces.
-
If you want really, really fine wire, get a scrap piece of good coax, the type with silver plated shield and take apart the shield. Nice small silver plated wire. I have a little bag of this stuff I keep for those occasions I need really small wire on a PCB.
Wally