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April 6, 2012 6:28 PM   Subscribe

How vigilant / attentive should I be about magnets hurting my electronics?

I've often heard and seen evidence of the negative effects of magents on electronic devices, especially those with memory / hard drives. What kinds of frequently used household devices / tech devices should I be aware of as containing magnets, and how cautious should I be about their proximity to which other kinds of devices?
posted by lazaruslong to Technology (5 answers total) 2 users marked this as a favorite
 
Actually, most of the time you're pretty safe.

Magnetic disks (pretty much just hard drives these days) are susceptible to corruption by magnetic fields. But, it needs to be a pretty strong magnet to even penetrate the case and get to the platters.

CRT monitors and televisions are badly affected by magtnets. Leave a magnet on top of a television (especially older ones), and you can permanently ruin the image tube. Plasma TVs may be affected too; I've never had one to play with like that.

Things with electric motors can sometimes be subtly screwed up by magnets. CD drives/players, for instance.

As for what has magnets in it? Hard drives (awesomely powerful ones, actually). Speakers, which is why you don't put not-designed-for-computer-use speakers next to your CRT monitor--as I learned the hard way.

The pouches for some cellphones have magnets to detect the presence of the pouch and put the phone to sleep. The power connectors on Macs are magnetic.
posted by Netzapper at 6:43 PM on April 6, 2012


Netzapper: "CRT monitors and televisions are badly affected by magtnets. Leave a magnet on top of a television (especially older ones), and you can permanently ruin the image tube. Plasma TVs may be affected too; I've never had one to play with like that."

It's not necessarily permanent, but it is a pain in the butt to manually degauss a monitor, so in that respect it is best to keep the strong magnets away from the TV.

The reality of the situation is that you're unlikely to do any damage to your electronics unless you're playing with a rare earth magnet or you get a wild hair and run a fridge magnet up and down the magnetic stripe on your credit card or otherwise actually attempt to do something silly with magnets.
posted by wierdo at 6:47 PM on April 6, 2012


If it's of any help, I have been specifically been told that cell phones are not affected by magnets. (credit cards, on the other hand...note to self. Do not carry around neodynium magnets in purse.)
posted by Ys at 8:10 PM on April 6, 2012


The only time magnetic fields cause problems is when other magnetic fields are in use. Mag stripes, spinning-disk hard drives, motors, cathode ray tubes, etc - they all depend on magnetic fields in order to get their job done. So if you have a little bit of knowledge about the thing you're trying to assess in that way, it's a pretty easy call. Solid state electronics like calculators or LCD screens or iPads don't rely on magnetic fields for their operation, and unless we're talking about fields measured in whole Teslas, they aren't affected by them at all.
posted by TheNewWazoo at 10:58 PM on April 6, 2012


Oh, a really, really simple two-step test: is it delicate, and does anything in it move?

If it's delicate - that is, not a refrigerator or a fan or a big speaker - chances are good that it won't be effected by magnetic fields.

If nothing moves - that is, there's no motion like a reel spinning or swiping a card - chances are also good that it won't be effected by magnetic fields.

CRTs are a notable exception to that, but they're going away pretty quickly.
posted by TheNewWazoo at 11:04 PM on April 6, 2012


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