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Comment by gerdesj | Hacker News Reader

The OP is a lovely work and beautifully illustrated.

I recently spent 18 months working from our dining room table. I regularly have to worry about swapping out broken hard discs in my work data centre. I took a 3.5" SMART failed SAS drive apart fairly recently and turned the two magnets into fridge magnets. My wife cannot physically pull them off (ooerr missus) the fridge directly. She has to slide them to an edge or use a lever.

The grandkids' latest artistic efforts stay stuck to the fridge and so do appointment cards etc. My step-mum grabbed at one of those because she thought it was falling off and the door opened instead and then the painting ripped. Calamity! We got the little darling to do a copy and great granny calmed down a bit.

It's a shame that more people aren't commenting on this page. It is lovely.

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> It's a shame that more people aren't commenting on this page. It is lovely.

The illustrations are nice, but they often make so little sense: the topic is mostly about molecular interactions, yet the illustrations show macroscopic scenery. Also, the entire article reads like a grab-bag of Wikipedia entries, and only the first paragraph of each entry. I thought this was going to be an in-depth article about magnets! Furthermore, the entire page including the text is an image, which is not how the web is supposed to work.

Also, their induction hob appears to be on fire.

A friend of mine used to work at Western Digital. He had a magnet from a 10k RPM SCSI drive on his cubicle. If you tried to lift it straight off rather than pry it, you would just lift the cubicle.

I use hard drive magnets as key hooks. Keys themselves don't stick, but the keyring does and holds great. I put my business card under mine and the wife's under hers both to label and to have a way to eventually remove them from the fridge.

I also superglued two to a pair of old Xeon CPUs that look really cool and have enough lip to be easily removed. They make ideal fridge magnets!

You reminded me of an old trick (now expired) that my grandma taught me: take the magnet out of used Sonicare toothbrush heads, wrap the magnet in electrical tape creating a pull-tab, and you have a rather powerful refrigerator magnet! Sonicare removed the original magnet vibrating mechanism quite a while ago so this no longer works, but I love creative reuses like this for items.

How do they vibrate, then?

Looks like the original version is driven by a coil electromagnet which deflects rare earth magnets in the brush head. https://www.powerelectronictips.com/teardown-whats-inside-a-...

I am 100% unsure, but if you hold a modern Sonicare toothbrush head up to a refrigerator door the magnetism (if any) is not even strong enough to hold the head to the door. The old models had two dark-black rectangular magnets (many of which I still use to affix postcards to my fridge) and the new ones have light silver circular “magnets”. The ‘how/why’ is well beyond my scope of knowledge.

Warm them a little and you can make them weaker. you have to be gentle though. Edit: Curie temperature of neodymium magnets is 320°C so "a little is relative".

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