[HN Gopher] Magnetically Modelling MagSafe
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Magnetically Modelling MagSafe
Author : kavinaidoo
Score : 73 points
Date : 2023-10-28 09:25 UTC (13 hours ago)
(HTM) web link (kavi.sblmnl.co.za)
(TXT) w3m dump (kavi.sblmnl.co.za)
| stereo wrote:
| 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...
| tjoff wrote:
| 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).
| rmellow wrote:
| 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.
| tjoff wrote:
| 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.
| alpaca128 wrote:
| 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.
| JoBrad wrote:
| 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.
| 8ytecoder wrote:
| I've not had that happen ever. MagSafe manages to align
| the phone perfectly.
| mort96 wrote:
| 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.
| skyyler wrote:
| It was how wireless charging worked in the Palm ecosystem,
| with their touchstone wireless charging dock.
|
| That was around 2010, as well.
| buildbot wrote:
| It was a really great feature, really well implemented too.
| It's sad webos and the palm pre never really took off.
| arcticbull wrote:
| 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
| Arainach wrote:
| 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.
| tjoff wrote:
| 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.
| afandian wrote:
| Are magstripe cards expected to survive that?
| alexdbird wrote:
| 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.
| somehnguy wrote:
| 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.
| IggleSniggle wrote:
| I lost the ability to use a parking exit card (mag swipe)
| due to a having a magnet in my wallet a year ago.
| LtWorf wrote:
| 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.
| NavinF wrote:
| 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
| dontlaugh wrote:
| Are they still used? None of my cards have one.
| afandian wrote:
| 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.
| dontlaugh wrote:
| Also UK. All of my renewed ones lack magstripes, I didn't
| realise they're still around.
| andreareina wrote:
| https://web.archive.org/web/20231028092556/https://kavi.sblm...
| willis936 wrote:
| 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...
| j_bum wrote:
| MKBHD did this with the iPhone 13 Pro:
| https://youtu.be/dSL6KiMeNOI?si=rI0-FYrf0ZHt9FYQ
|
| Magnet paper goes on at around 0:15
| anfractuosity wrote:
| 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
| philsnow wrote:
| United Nuclear has those
| https://unitednuclear.com/magnaview-film-p-629.html
| anfractuosity wrote:
| 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
| blincoln wrote:
| > 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)
| richk449 wrote:
| Any idea where I could buy this? It would be really helpful
| for my work.
| anfractuosity wrote:
| 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
| kavinaidoo wrote:
| 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.
| RGBCube wrote:
| The costs of not using Cloudflare :)
| linuxdude314 wrote:
| Was expecting to see Maxwell's equations and an actual model of
| MagSafes magnetism.
|
| This is more or less an exploded diagram.
| 3seashells wrote:
| 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.
| peter_d_sherman wrote:
| 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!
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(page generated 2023-10-28 23:01 UTC)