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Toxic Magnet Wire? Answered

I know I'm probably going to sound like an idiot for asking, but can magnet wire release any toxic fumes when heated? I made a speaker using a magnet-wire coil and a neo-magnet, and when I plug it into the amp, I realized the coil gets very hot. I was expecting this, for I've used a number of coils in other projects.

There is an odor, no doubt, that comes from every coil I've used when making an electromagnet. Sure, the smell may come from the iron nail being heated, but I always associate the smell with the coil. I'm not willing to smell this speaker, however.

So, is there any risks that come from the heating of magnet wire? The coil gets hot after about a minute of run-time, but I'd like to be able to run through an entire album of music (an hour?) if possible. Thanks!

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freethetech (author)2011-06-24

I need an urgent answer! The speaker began smoking and, after viewing it, I realized the electrical tape burned. This is bad, I assume?

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caitlinsdad (author)freethetech2011-06-24
Happens all the time. Don't panic.

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freethetech (author)caitlinsdad2011-06-24

Well, I am a bit insane when it comes to anything smoking, so I took proper precautions and air-ated the room for two hours.

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CrLz (author)2011-06-23

Also, note that neodymium magnets have a low Curie temperature and are flammable. So heating from your coil could degrade / damage the neodymium pole.

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Goodhart (author)2011-06-22

In high concentrations, I'd say yes, it is toxic....but I doubt you are using it and sitting with it, inside a small box :-)

Crapflinger is right though, there shouldn't be THAT much amperage going through the wire to make it smell (overheat), that is normaly the smell you get from a "shorted or over powered or stalled electric motor winding" and in any case indicates something is terribly wrong. Either too much current is being forced through the wire, OR you have some residual DC coming from somewhere. High amperage DC current will not see the coil so much and will course through it like any other wire, except if the wire it thin enough, the current could see the coil as just another nasty short,.

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crapflinger (author)2011-06-22

i'm in NO WAY an electronics expert, but i do know that commercially made speakers' coils don't get hot (at the very least, not hot enough to start melting the coating on the wires). methinks there's something wrong with your system

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freethetech (author)crapflinger2011-06-22

The coating on the wires aren't melting. This is expected simply because when magnet wire coils have current passing through them, they get hot. It's something that always happens.

When the volume of the amp is turned to about halfway (20/40), the coil stays fairly cool. This is because when the "sound" goes from the amp to the speaker (the speaker turns it into vibrations), they are simply pulses of electricity. The volume changes the intensity of these pulses. More electricity in pulses = more electricity to coil = heat.

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crapflinger (author)freethetech2011-06-22

i understand how electricity, electromagnets and speakers work. that's not the issue, NORMAL speakers don't give off a smell unless something isn't working correctly.

which suggests that you're either using the wrong material in general, or you're overpowering something that's creating too much heat.

i mean you're not making an electric heater, the efficiency of your system should be high enough to not cause the wires to heat up enough to cause the wire coating to release fumes (which is the wire coating melting by the way...it may not be visibly melting, but you're smelling the fumes because you're changing the solid coating into a gas)

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verence (author)crapflinger2011-06-22

+1

It's true, more energy will heat up the coil, but a coil that hot that it is smellable is just an olfactory sign of a bad design.

Decrease the maximum power or increase the the allowed load of the coil.

The coating doesn't need to melt (or even be close to the melting point). It probably would not melt anyway but just decompose - in the way that paper doesn't melt but turns into carbon and fumes if heated up. The smell is a sign that higher volatile components of the coating are released. Not a good sign. 'nuff said.

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freethetech (author)verence2011-06-22

I improved the design. It is much more effective and gives of no smell or odor. I also concluded that having the volume on the amp at full blast isn't helping the situation. I played with the amp settings and volume, only to find that 15/40 is enough to make this thing heard from a nice distance.

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gmoon (author)2011-06-22

The risk here is that you'll overheat the magnet wire, melt the insulating coating and short the amp.

Amplifiers are designed to drive a load of a specific impedance (think of it as AC resistance), and if the load is off by too much, you could fry the amp...even if it doesn't short. Many modern amps have protection from this sort of thing, but not all do.

What's the DC resistance of your coil? I think it's great you made your own speaker, but it should be at least close to the spec'ed impedance of the amp...

Speakers usually test for DC resistance slightly lower than their rated impedance (like an 8 ohm speaker will test as ~6.4 ohms). But the "resistance" becomes higher at various frequencies (actually that impedance thing, not DC resistance).

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