How to (Re)Magnetize a Permanent Magnet

How to magnetize a permanent magnet and how they work. We re-magnetize a permanent magnet that lost its field, and also look at how permanent magnets are related to magnetic domains in materials like iron and what material properties make good permanent magnets.

[oseyedian]

Nice point when you mentioned the toughness of a magnet through the BH curve.
I've never thought of that like this before.
This type of looking at things means a lot to me.
Thank you very much for sharing your passion with us.

[HitAndMissLab]

I never understood what Amp Turn is, now I do :-) Thanks for basics.

[lawrencejelsma]

I finally broke down 2.5 Watt speakers from 1968 since the cones were extremely dried out by weathering and the magnets around the speaker cone still are strong. Ferrite magnets remain polarized by weathering if temperatures never got hot enough to unalign those magnetized dipoles that were originally locked in place. For nearly 60 years Ferrite magnets remain strong.

[fifteen]

Very cool. When recharging a magnet, I use a compass to determine the magnet's polarity. It'd be cool to demonstrate this for the community so folks can work on magnets that are not color coded.

[scottthomas]

When I was in elementary school, the science teacher hung an iron rod om strings from the ceiling, oriented north south...after a few months, it was weakly magnetized ( could pick up a few pins)..
Two jobs ago, we had a magnetizer/demagnetizer. It was just a coil driven by 120VAC. Just push the button briefly to magnetize, hold it down and slowly withdraw the screwdriver to demagnetize it.
Your videos should be shown in schools!

[juliuszuben]

Found your videos very informative and it is surprising you don't have much more views

[chrisdickens]

Thank you. I learned a surprisingly
large amount from this video!

[KravchenkoAudioPerth]

A nice discussion on magnets. I work with engineering loudspeakers and most of what you said is spot on. I think some of the permanent magnets have a higher B value, but you were speaking in generalities. Did you hear me saying that's not a steel magnet! It's a ferrite. Greetings from near Ottawa!

Mark

[williammorris]

Making magnets at the forge make so much more sense now that you mentioned the lava. 🔥

[viterbo]

came here after you sent me from another video haha. you do a great job of making it digestible you are an excellent teacher sir

[davidahiwaaynet]

Fascinating and thanks for this explanation!

[ThriftyToolShed]

Great video! Looking forward to the demagnetizing video!

[emirlie]

nice tutoring, followed by excellent application of theory.. you got an instant sub here sir.

[emilalmberg]

Thanks for walking us through the basics.
I recreated the magnetism of those horseshoe magnets that are in old phones to make the ringtone, once.
I just wound on coarse wire and connected to some series connected car batteries, nothing you should do.
- But it worked!

[roddy_]

Definitely more intrigued to learn about electro magnetism and more of physics as a whole I never payed attention in class unfortunately but science and math where always interesting topics. Nice video thanks for the simple explanations

[carlosanvito]

Thanks for using Robertson screws in your high tech detector - they are much more accurate than dreaded slot and Phillips screws!

[edwardromana]

Another way, maybe better, is to charge a suitable capacitor and dead short it against the magnet coil. With some care, from the B and H diagram one can obtain the (co)energy density of the magnet metal per gram or cc and calculate the total magnetization energy required by the magnet in Joules. Then using a generous safety factor let that be the capacitor energy before the short

[manla]

I am the first time to see your videos. It is very well executed and explained clearly. I wonder what your current supply look like. Thanks again for your wonderful video.

[sparkyful]

Great video again! Regarding this I have a question about motors in my Nagra tape recorders. In these motors the rotor is a coil of wire with no laminations with inside there sits a permanent magnet which is completly enclose by the coil. To replace the ball bearing inside the complete coil and magnet has to be taken out of the housing. This then needs to by kept in a special cylinder (mu-metal?) so the permanent magnet doesn't loose its strenght. Can these Alnico magnets loose there magnetism so quick if it is kept outside of the motor housing? I found this rather strange. Its all in the manual and reads that if its not done like this the motor needs to be send back to the factory in Switserland to be re-magnetised. Sorry I can't show pictures of it here!

[gfr]

As a geolist I apreciated that you talk about paleo magnetism.