Magnetically Modelling MagSafe | Hacker News Reader

Magnetically Modelling MagSafe

kavi.sblmnl.co.za

79 pointskavinaidoo36 comments

https://web.archive.org/web/20231028092556/https://kavi.sblm...

The web server seems to have received the HN hug of death, but there's a video by the same author at https://www.youtube.com/watch?v=iAMtdQ-h_dk

There's also a cached version of an old magsafe article on that website by the same author at https://webcache.googleusercontent.com/search?q=cache:msNKQI...

Ah, that magsafe. As an android user that is the only thing I yearn from the iphone.

Feels like a requirement to do wireless charging (note, I have not played with wireless charging despite having it on and off since 2010, so I could be mistaken).

Magsafe is not wireless charging.

A Magsafe cable/port is a "trip safe" charging system, as the power cable is attached to the computer solely by magnets so that it will not break the port if yanked out at an angle.

No, the article (and linked youtube) is about the magnets on an iphone (apparently also called magsafe, hence the "that magsafe" part of my comment). This, among other benefits, aligns the phone perfectly and thus alleviates wireless charging alignment issues.

Which at least 10 years ago used to be a big issue. Not sure how current iterations perform.

This magsafe wireless charging system is great, although you still have to make sure it actually starts charging because the magnets can align it incorrectly if the phone placement is too far off.

I’m not sure how this would happen, if your case fits the phone correctly. When I put a MagSafe case on my phone, I get an animation showing that it fit. Subsequent attachment of MagSafe components just need to align with the case, since the case is already aligned with the phone.

I’ve not had that happen ever. MagSafe manages to align the phone perfectly.

The magsafe cable/port you're talking about exists, and is on the current line of MacBook Pros.

However, the magsafe feature on iPhones is something completely different, it's the system where they have magnets in the back of the phone which can be used to attach various accessories, attach the phone to mounts, or guide the phone to rest correctly on wireless charging pads.

It was how wireless charging worked in the Palm ecosystem, with their touchstone wireless charging dock.

That was around 2010, as well.

It was a really great feature, really well implemented too. It’s sad webos and the palm pre never really took off.

Agreed, webOS was really cool. It ended up acquired by HP and subsequently LG who use it for TVs now.

https://www.lg.com/us/experience-tvs/smart-tv/use

If Peak Design makes a case for your phone, they're Magsafe-compatible. Probably not literally to the spec, but they've worked with every accessory I've tried, chargers included.

Thanks, it is compatible and I've been eyeballing one since my comment :)

I'm not a fan of cases, so it hinges on how bulky it is. But it looks like a solid product.

My understanding is that Qi2 will be magsafe-compatible, which bodes well for future android phones and accessory support.

Are magstripe cards expected to survive that?

That's not an issue in most of the world; I don't think any of my current cards have ever been swiped. However there are still plenty of transit tickets that use a magstripe, and having those wiped is super inconvenient.

Hotel keys are what comes to mind as the only cards that I still swipe. A year ago I checked into a hotel and went back out to the car to grab my stuff - when getting back in I learned that I had immediately wiped the magstrip by putting it in my phone pocket. Had to reroute right back to the front desk.

I lost the ability to use a parking exit card (mag swipe) due to a having a magnet in my wallet a year ago.

I was in vacation in greece and we had issues because seemingly the phones reset their magnetic keys, so we needed a new one daily until we were told to keep them in a different pocket.

All the magstripes on my credit cards, library card, etc survived magstripes for over 2 years now. Tho I guess I wouldn't know if a card got wiped recently since I've been using contactless+biometric payments for almost the same length of time in the US. I've had paper magstripes (Paris metro tickets) wiped by magsafe so it's technically possible if the magstripe is extremely cheap/weak. IIRC metros are phasing out paper tickets for this reason

Are they still used? None of my cards have one.

All the UK payment cards I've ever had have one. I don't know if ATMs use them or the chips. For payment itself contactless is now the norm.

UK printed train tickets are all magstripe. There are phone-based alternatives and contactless payment card alternatives in London. But the magstripe tickets are still mainstream.

Also UK. All of my renewed ones lack magstripes, I didn’t realise they’re still around.

It appears that my web hosting can't survive hacker news. Sorry for that! Thanks to andreareina for commenting a working archive link. Also thanks to stereo for commenting my intro YouTube video and another post I wrote on MagSafe.

The costs of not using Cloudflare :)

Does anyone have some magnetic film and a second camera? I'd like to see the field cross section.

https://www.magnetshop.com/magnet-accessories/magnetic-field...

MKBHD did this with the iPhone 13 Pro: https://youtu.be/dSL6KiMeNOI?si=rI0-FYrf0ZHt9FYQ

Magnet paper goes on at around 0:15

There's also another type of magnetic viewing film that doesn't seem to use oil filled capsules with flakes of metal in.

This is a picture I just took, it doesn't really do it justice but you can get rainbow like effects from it - https://www.anfractuosity.com/files/mag2.jpg

This is the same film with a special type of cylindrical magnet below - https://www.anfractuosity.com/files/mag1.jpg

Edit: It seems to be this - https://en.wikipedia.org/wiki/Magnetochromism it seems to use encapsulated iron oxide nanoparticles in water in a film

United Nuclear has those https://unitednuclear.com/magnaview-film-p-629.html

That looks like the type with nickel flakes to me (https://en.wikipedia.org/wiki/Magnetic_field_viewing_film), as it's not showing different colours

This video https://www.youtube.com/watch?v=yfdq3oA6-4M shows the colours better than my photos

> That looks like the type with nickel flakes to me

I agree. It's a night and day difference versus the magnetochromic viewing film. The monochrome film doesn't reset itself after the field is removed,[1] and the contrast is not as good.

I bought both types on Amazon a few years ago. The specific magnetochromic film I bought at the time disappeared from Amazon (along with its vendor) shortly thereafter, but it seems like at least one seller has the same kind of product again.[2]

[1] I suppose this might be useful for some applications, but I dislike the "ghosting" effect.

[2] https://www.amazon.com/CMS-MAGNETICS-Green-Magnetic-Viewing/... ("Olive Film" variation specifically)

Any idea where I could buy this? It would be really helpful for my work.

I'm not sure which seller I used afraid, but there's a number on aliexpress such as in the links below, it has kind of an olive colour like blincoln noted.

* https://www.aliexpress.com/item/1005005510364934.html

* https://www.aliexpress.com/item/1005004242373777.html

The colour apparently relates to the field strength too

There's something weird-but-interesting (or interesting-but-weird, if you prefer!) going on here...

The following image, while not the best representation, alludes to it...

https://web.archive.org/web/20231027215551im_/https://kavi.s...

Basically, the way I conceptualize it, is as follows:

Given two simple magnets (A and C) in motion, approaching one another's proximity, but not on the same plane so as to cause impact, as might be the case inside of an electric motor -- the magnetic flux will swing in normal predictable ways...

Nothing to see there...

But given four (or more) magnets, A, B, C, D -- where A and B are close to one another and fixed in position and cannot move relative to one another, but both of them can move as a group, relative to magnets C and D (who are also similarly fixed in position near one another, and can't move relative to one another, but both C and D can move as a group, relative to the position of A and B)...

Well, given all of that, there would seem to be some magnetic arrangements of A and B (and C and D) -- where the fields generated by the combined orientation of A and B -- will swing wildly when approached (and subsequently receded by) C and D...

These magnetic arrangements, orientations, of 4 magnets or more, with sets of two being fixed in position -- could be worth exploring -- based on the wild field swings they could potentially produce...

Applications?

Well, I don't as-of-yet know! But the future, I'm sure -- might invent some!

For now however -- it might make for some interesting, purely curiosity-driven explorations!

Was expecting to see Maxwell’s equations and an actual model of MagSafes magnetism.

This is more or less an exploded diagram.

Magnetic connectors were the bane of my existence with laptops on industrial manufacturing or actually any place that produces occasionally Metall swarf. Classic designers and engineers ignoring use cases.

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