Introduction: Magnetic Wire

Picture of Magnetic Wire

Magnetic wire is used by hobbyists and engineers for coils, inductors, transformers, and solenoids, and it is not cheap to buy at $25 to $60 dollars a pound. This is the wire I gathered in one weekend for no more cost than my time. The ten pounds of salvaged magnetic wire from 16 AWG to 34 AWG would have cost me about $300.oo dollars to buy new. And that doesn’t include the other salvaged parts like heat sinks, transformers, and other components as well as sellable scrap.

I have a homemade coil winder I use to make my own custom transformers, coils, and solenoids that I use in my projects like this auto loading coil for a coil gun, or my first coil gun where I made the step up transformer as well as the propulsion coil.

As a green project this one saves energy in the making of wire and other components as well as recycling, one of the biggest savings is to your pocket book.

Step 1: Locating the Magnetic Wire

Picture of Locating the Magnetic Wire

I get most of my magnetic wire from working TVs and Monitors, people are throwing these out because they are upgrading to the new stuff on the market. Or in the case of TV sets upgrading because the transmitters have gone digital and the old analog TVs can’t receive the signal.

The yoke ring coils as indicated in the second photo with the yellow arrows, the yoke ring coils consisting of 28 to 34 AWG wire are in the front and the back of the yoke.

The lacquered yoke coils wrapping the yokes ferrite cores indicated by the red arrow in the second photo are too hard to salvage for reuse as magnetic wire, however they bring as much as $2.50 a pound cleaned copper.

The picture tube coil indicated by the yellow arrow in the third photo, on the back of the picture tube can be wrapped in electrical tape, foil wrap, and shrink tube. The magnetic wire in this coil can be 24 to 34 AWG.

Step 2: Gaging the Magnetic Wire

Picture of Gaging the Magnetic Wire

The yoke ring coils are small enough to store without transferring to a spool so I just measure them and mark them by size and approximate length.

For this you need three things, a 1 inch outside micrometer, a tape measure, and an Insulated and Bare Copper Wire Table. For my tables I use my book, “Electronics Vest Pocket Reference Book, By Harry Tomas.”

This book is a quick reference for color codes, circuit examples, formulas, and tables used by technicians and engineers alike. If you find one of these books don’t lose it I have been offered a hundred times what I paid for mine. The tables have every dimension and property of wires and other basic components you need for electronics.

This yoke coils wire is 0.0115 of an inch in diameter on top of the insolation #34 AWG wire is 0.0106 to 0.0118 of an inch on top of the insolation that makes this wire #34 AWG magnetic wire according to the Insulated and Bare Copper Wire Table.

Then using the dimensions of the coil 0.25 x 0.25 thick bundle divided by the thickness of the wire I get 484 turns on the coil.

Next from the center of the coil bundle I measure the diameter of the coil and get 5.5 inches and multiply that by Pi giving me 17.3 inches in circumference.

Multiply that by the number of turns and you get 8373.2 inches or 697.8 feet.

So I have just less than 700 feet of #34 AWG magnetic wire and I record this on the side of the coil.

Step 3: Cleaning the Picture Tube Coil

Picture of Cleaning the Picture Tube Coil

Never hurry this, take your time cleaning the picture tube coil.

Start by finding the end of the electrical tape, this is usually near the leads of the coil and take your time exposing the ends of the leads.

Trim off the leads and expose more of the wire.

Then measure the diameter of the wire, this wire is 0.0255 inch in diameter on top of the insolation, #24 AWG is 0.0251 to 0.0268 inch in diameter on top of the insolation that makes this magnetic wire #24 AWG according to the Insulated and Bare Copper Wire Table.

Since I have the loose wire exposed I just count the number of turns coming to 120 turns on the coil.

Now I can measure the outside of the wire coil with the measuring tape and get 62 inches in circumference and multiply that by the number of turns and get a length of wire out in left field. Or I can reshape the coil round measure the diameter of the coil from the center of the bundle coming to 18 inches multiplied by Pi giving me a circumference of 56 inches. Now I multiply that by 120 turns giving me 6786 inches or 565.5 feet.

Now I can mark the coil #24 AWG and 565 feet and place the coil in storage, or I can remove the rest of the electrical tape and transfer the wire to a spool. In my case I like to make the wire easy to store so I remove the tape leaving just a tab of tape keeping the coil from unwinding until I can spool it.

Step 4: Spooling the Picture Tube Magnetic Wire.

Picture of Spooling the Picture Tube Magnetic Wire.

I save spools from fishing line, ribbons, wire and other sources just for jobs like this; I start by selecting a spool large enough to hold all the wire I am spooling. Remember the bigger the coil I am salvaging the larger the spool I need. I drape the coil of wire over the back of a chair and starting at the outside end of the wire and taking my time I start winding the wire around the spool until all the wire is on the spool. When that is done I mark the spool with the wire size and length.

Step 5: Epilogue

Picture of Epilogue

This is roughly $150.oo of wire I salvaged in 1 evening while I watched TV, but that is not all I salvage. I salvage the transformers, heat sinks, wires, and components from the circuit boards. I have run across power transistors that are $85.oo each new let alone heat sinks that are impossible to find. And that is for components they still make. But most of all it saves these things from ending up in the landfills.


MarkM196 (author)2015-12-07

I need to purchase some 14ga bare copper wire for a magnetic coil project. On eBay, there are several choices available: Round, Half Round, and square. There is also: Soft, Half Hard, and Hard. Can you help explain why some of these choices would work better than others? Thank you in advance.

If it is magnetic wire it is not quite bare it has a lacquer coating.

Round, Half Round, and Square, square is the same diameter as round and carries more current than round. Then there is air gap, more or less turns in the same space and an evenly dispersed magnetic field.

Soft, Half Hard, and Hard, impedance per foot and hard bends less easily, the most common use is soft on the stator, and hard or half hard on the armature. So centripetal force won't blow the armature apart.

Roehdy. (author)2015-11-30

Great day sir, favor pls, i want to build a 220VAC/ 1OOO WATTS pm motor.what size of magnetic wire will i use for low rpm and how many would it be to function well,im using vacum stator .thanks

Josehf Murchison (author)Roehdy.2015-12-01

Induction motors determine speed by cycles and winding however you are looking at about 16 gaege wire.

garben04 (author)2015-11-09

I built this small generator right here:

My question is: Can this generator be made out of plywood instead of cardboard? It is a little weak when I want to get 400 windings. Wouldn't the magnetic force (so the voltage) be lower because the plywood may disturb the magnetic field?

Many thanks in advance.

Plywood should work just as good as cardboard, maybe better because you can get the windings closer to the magnets using thinner plywood and still have the same strength.

That would make a good Instructable the next time they do a cardboard or paper contest.

agis68 (author)2015-11-27

yes CRT tvs & monitors are the best magnetic wire supplier and not only....(Once weighing the total mass of the most important salvaged electronics from a 32" tv was arround 5-6 kg)!!! And its even better to find an old but still working TV cause you don't have to aware if something is disfuctional.....

garben04 (author)2015-09-09

I want to build a small generator for a small wind turbine. I don't know how much (length) copper wire I need to use, and which thickness it needs to be. I don't want to light a tiny 1V lamp, I'd like a higher voltage (to maybe light a normal light bulb). Could anybody help me with this?

Current and number of poles dictates wire thickness.

RPMs and turns dictates voltage.

Length of wire is dictated by parameter of poles.

RPMs is dictated by wind, gearing, and screw type.

Then you have generator types, brushless, regulated, permanent magnet.

So research wind where you are decide on generator type and experiment.

It's actually for my school project. So, the thicker the wire the higher the current? And the more turns per minute the higher voltage? Is there a formula to calculate this?

And i don't know if I need to have DC or AC.

Thank you.

Yea but there is to much to put in a reply.

Google wind turbine generator design.

And check free online programs like this one.

Northrrn_Joe (author)2015-07-28

Is there anything dangerous inside a television?
Is potentially lethal electricity still inside an unplugged TV?
If so, what precaution should be taken?

I've been wanting to try some simple DC motor experiments with my stepson but I don't want to buy special magnet wire if I don't have to.

Yes high voltage can be stored in a number of places for a long time even with the TV unplugged. I short the prongs of the power cord and ground the high voltage of the flyback. The red wire that goes to the side of the picture tube. If you are working with a TV that has tubes instead of transistors you may need to short all the capacitors one at a time. If you are not sure short all the capacitors and the flyback. After that there is the gas from the picture tube if you crack or brake the tube it will suck air in first and then the gas will leak out it has mercury in it.

goldenshuttle (author)2014-12-28

very useful. Many thanks

DemolisionWolf (author)2013-06-04

I'm new to electronics, what is the difference between magnetic wire and copper wire?

Copper wire is copper wire but magnetic wire is all about the insolation, with magnetic wire the insolation is designed not to be or inhibit the windings from being a capacitor.

A capacitor is a simple device; it is a conductor and an insulator.

Think of every component in a circuit as a resistor

A capacitor is an insulator with dc current, but apply a frequency to it and it is a resistor.

An inductor coil is a dead short with dc current, but apply a frequency to it and it is a resistor.

If you really pay attention to what electronic components do they are all resistors.

It is all about making sure the inductor is an inductor and not a capacitor.

By the way a very good question.

Robin- (author)Josehf Murchison2014-07-14

Hello Josehf:

When you say "insolation" you mean "insulation." Insolation means: "solar radiation that has been received" and, as mentioned above, "magnetic wire" would imply an iron based wire, which would react to a magnetic field.

Josehf Murchison (author)Robin-2014-07-14

Ah don't pick on words it is not that important if you get the point.

ohh that makes sense, thank you. next question- so if i wanted to make an electromanet, using magnetic wire would be far more effective than copper wire?

yes the insolation is thin on magnetic wire enabling you to get more turns in a smaller area.

just one thing with high voltages you may want fish paper between the layers it also further reduces the capacitance of the windings.

Thanks for the info!

Oh I forgot to mention did you notice the wires are different colors.

Red is low frequency

Gold is all frequencies

And green is audio

Actually thin is high frequency and thick is low frequency due to the skin effect.

Somebody tell those china manufacturers that the wire that they use in headphone cabling makes great litz wire and they have buyers here...

tcarney57 (author)charlieb0002014-05-08

Well, wire is wire. Though the term is used here in this 'ible, there's no such thing as "magnetic" wire. What the author is showing here is called "magnet"--not "magnetic"--wire because that's one of its common uses: electromagnets. Since most copper wire is coating with some sort of insulation, and magnet wire is coated with one kind of such insulation, then it's just the same as any other wire. The lacquer-coating insulation is often more convenient for the purposes the author discusses here, but it still just insulated copper wire. Except for it bulk and sometimes the "dielectric" properties of the insulation, various kinds of plastic-insulated wire can be used for many--if not all--of the applications shown in this Instructable, including coils for RF applications.

cdigman (author)2014-03-31

Is there a way to connect two pieces of magnet wire and have them work the same? Possibly by coating the soldered part with liquid electric tape? I need to make two coils with 6lb of wire each for a magneto magnet charger.

Josehf Murchison (author)cdigman2014-03-31

Yes you can join the ends however if it is a high voltage side of a toroid or a transformer make sure the joint is in fish paper as well as well insulated it is better to have the joint outside the transformer.

Fish paper is a paper you put in between the wrap layers to prevent arks inside high voltage coils it also inhibits capacitance storage in a coil.


cdigman (author)Josehf Murchison2014-03-31

It is for a magneto magnet charger for mags before WW2 when they came up with perminant magnets. It's basicly a big electromagnet

jmpm4619 (author)2014-01-15

Okay and How Will this magnetic coil react to another magnet... Does it attract ,Repel, Or repel and attract to another magnet ?

Here is something you can try that is fun, connect the coil to a battery then put a compass near it. The compass will follow the magnetic field of the coil use a 12 volt battery.

jmpm4619 (author)2014-01-15

What would happen if I cut the circular wire on the chair and place a battery at each end?

Ok if you joined a battery to the ends of the wires you would get a magnetic coil.

bigdaddy8951 (author)2013-12-03

A good instruct. I do have a question though. Why is the lacquered yoke coil wire not worth salvaging. There seems to be quite a bit of wire there.

Keep the info coming.

Dipped coils like the lacquered yoke are almost impossible to take apart without destroying the wire.

The only thing you can do is burn, bake, or use paint stripper to take off the lacquer, this would also take off the wires insolation and brittle the copper.

You would need to build a device to de-temper and reinsulate the wire, you might as well be making your own wire from scratch.

Easier to get paid for the copper

rimar2000 (author)2013-05-30

Josehf, you are like me, always recovering things from the waste. But you are more clean and neat doing the work. I have some pound of copper wire too, but it is in many little hanks.

I came from a family of little assets my first bicycle I built out of parts from the garbage. By the time I was 14 I taught myself TV and home entertainment repair by taking TVs and other household articles out of the garbage repairing them and selling them.

Wow, that is very worthy, Josehf. It is not my case, I had many opportunities in my life, and and let it go too much.

Life is like that.

About This Instructable




Bio: I am a photographer, a tinker, an electronics technology engineer, and author; I write short stories and poetry for the love of writing. I started ... More »
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