Electromagnets

Hey, i need to research on electromagnets and i want to know how they work, how they are made, etc.

 

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Google electromagnets.

 

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i thought of that but i need scholarly references and articles, also i'm not just looking for some random source on the internet.

 

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But you are looking for some random person on the internet...

 

These kind of questions don't go down well at Sciforums. Particularly if it is for academic research. You would be better off reading the basics yourself first then coming here for specific questions on the topic. Nobody is going to want to write a huge post on how electromagnets work.

 

thank you for that.

 

Wiki tells you how they work, what they are made of, etc.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/elemag.html

 

i have another question, if you were to get a decent sized magnet, and pump up the current very strongly, would you be able to increase the pull? this is an electromagnet, and i know if you pump up the current enough the wire would blow, but what if the wire was made of a stronger material. is it possible to get a smaller size electromagnet to get the same strength as a very large one?

 

All this is on the internet, you know. But basically the magnetising strength of an electromagnetic coil is determined by the number of turns of wire it as and by the current. You can read about it all here: http://www.electronics-tutorials.ws/electromagnetism/electromagnets.html

So as you say, if you increase the current too far you melt the wire, but by wrapping more turns you can increase the strength without increasing the current.

 

Here is an electromagnet made of a thicker material, induction heating an aluminum cylinder:



The field does not increase without limit. Once a certain number (about half or even less) of the atomic magnets are aligned in the ferromagnetic core of the electromagnet, you reach a point of saturation. There is a hysteresis curve associated with this:

http://hyperphysics.phy-astr.gsu.edu/hbase/solids/hyst.html

 

I just need a really strong electromagnet because I need to build a non-lethal gun that launches a projectile using the electromagnet to propulse the projectile at least a couple feet.

 

Just Google "homemade railgun". Enjoy, and try not to electrocute yourself.

 

You'll shoot your (or someone else's) eye out. If it has to be portable, expect to be lugging around something the size of a car battery to power it, and also for the coil to get quite hot when energized.

How are you planning to make this thing "non-lethal"?

 

Is this because the magnetic field becomes so strong that it opposes the EMF inducing any more magnetic charge alignment?

 

Yes. You can do a simple experiment on a table top with a number (at least 3) of bar magnets to demonstrate why this happens. Separate the bar magnets far enough that they can lie flat and arrange them so that all of the North Poles are initially in the same direction. Then push them together sideways, trying to keep the North poles all in the same direction. Allow the center magnets to slide (or flip) on their own. The center ones will spontaneously flip ends, and this is basically what happens to the atomic magnets when a strong external magnetic field tries to flip them all in the same direction. Only some of them will flip.

If all of the atomic magnets were aligned in the same direction, the field would exceed the terrestrial record limit of about 26 Tesla and become a small magnetar. You wouldn't want to stand anywhere near it a drawer full of steel knives with one of those. Whatever it is that makes magnetar's fields so strong, our best science currently has no idea.

 

Coil gun:

https://en.wikipedia.org/wiki/Coilgun

 

A coil gun that heated the pellet to a molten liquid before discharging it would be cool.

 

Are you actually an electrical engineer danshawen? You have persistently made so many fundamentally wrong statements involving various aspects of EM I have to wonder. Regarding above claim, it needs a bit of translation into accepted terminolgy. 'Atomic magnets' is misleading and ferromagnetic (or ferrimagnetic) media is best described in terms of typically ca micron sized domains, each of which are intrinsically saturated. Overall media saturation occurs when *all* such initially randomly oriented domains are aligned with the applied B field, owing generally to a mix of domain rotations and preferential growth of favorably oriented domains via domain wall creep. A far easier process in magnetically 'soft' media vs 'hard' i.e. permanently magnetizable media. In certain special magnetic materials domains as such do not exist but such are rare exceptions.

 

Nice wrap up, Q-reus. Not every electrical engineer needs so specialized a knowledge of magnetism. All an audio engineer needed to know for instance was to occasionally degauss the magnetic tape heads, and align the azimuths with respect to the moving tape. If I seemed to make any claim other than knowing what a magnet is, or was used for, this was not intended.

Digital recording did away with such nonsense, and good riddance. It certainly took forever and three days for an industry so hamstrung in copyright protection to allow us to do that simple thing unencumbered. Digital Audio Tape was just a really unnecessary hassle. Technological junkyard fodder.

All I meant to suggest was, if there were a means to pre- align magnetic domains to the desired orientations and lock them there before transitioning, that would certainly be a useful means for producing unnaturally strong MRI class permanent magnets.

As far as I am aware, no one understands how magnetars achieve such impressive field strengths. You couldn't orbit one in anything other than in a plastic spacecraft. Even then, it would attract all manner of iron-laden space debris.