Are electric/magnetic fields dangerous to computers?

[TheNiceGuy]

Hello everyone!
I started wondering about this question today.
I just put my copmuter on my kotatsu (a Japnese heated table with fan/heater build into the under surface), and noticed my 22" CRT monitor image start to 'jiggle'. I figured out that the fan (not the heating element) is causing the image distortion (probably the electomagnetic field the dynamo creates). Blocking the fan doesn't stop the problem. But placing a heater element only near the monitor is fine.
So, what do recon is going on? Is this dangerous to any of the PC parts/monitor? And what would be safe? Could the monitor simply be moved away a bit, and the PC remain near the field area?

Wondering in Japan...

 

[itachi]

monitors, cassettes, video tapes, and floppies can be damaged by electromagnetic fields (emf). hard drives are based on magnetism so they should be affected too, but i'm not sure if they're shielded from magnetic waves or not.. if they are, than no harm to them. any other parts in the computer should be fine.. might get a bit of emi tho, but it shouldn't be so much that it's incapacitating.

fans are almost always based on electromagnetic motors.. which is the reason why the fan is causing the problems. i'd keep the fan as far away from the monitor as possible.

 

[f95toli]

Electromagnetic fields can definitly damage electronic equipment, that is how electromagnetic pulse weapons (EMP) work.
However, there are a lot of regulations meaning that consumer electronics is not suppose to emitt "dangerous" levels of electromagnetic radiation, and a computer is suppose to be more or less immune to "normal" levels of interference (both airborne and interference carried by electrical wiring); this is known as EMC (electromagnetic compatibility).
However, there are of course limitations and a fan will definitly interfer with the monitor if you place it too close (but the computer itself SHOULD be fine).

At work we used to have a computer close to a very powerfull magnet (a few tesla), whenever the magnet was turned on the screen (CRT) slightly shifted to the sides and the colors would change; about once every two years the monitor broke down. Eventually we just replaced the CRT monitor with a TFT screen.
The point is that we have NEVER had any problem with that computer (except for the monitor) and we have never lost any data, and the fields are MUCH higher than anything you would find in a "normal" enviroment. Note that this is a dc field, an alternating field of this strength would probanly have caused more problems.

 

[Matthias99]

Basically, what they said. Putting an electric fan/motor/transformer near a monitor will produce distortion and/or 'shaking' of the picture, as the EMF causes the electrons to be distorted in an irregular way. A static field (as f95toli described) would cause a continuous shift without 'shaking'. For a static field, you should be able to 'degauss' your monitor (either by turning it on and off a few times, or accessing the 'degauss' option in the menu if it's a more recent monitor) to correct it. At multi-tesla strengths, though, I'm not sure it would help much.

Exposing a monitor to any of these effects may damage it over time (or very quickly, if the fields are strong enough, but you are unlikely to have anything that strong in your house, unless you stick a rare-earth magnet on the screen or something like that). Parts in your computer case are generally much better shielded. Hard drives, in particular, are VERY well-shielded. I've seen people who claimed to put speaker magnets (which are very strong rare-earth magnets) *on* their hard drive and it didn't suffer any ill effects. If it can survive that, it will probably survive anything you can throw at it short of a focused EMP. Note that I do NOT recommend exposing hard drives containing anything you care about to strong magnetic fields unnecessarily. If there is any flaw in the shielding on your drive, you'll instantly ruin it.

 

[TitanDiddly]

In addition to the above, you heater may be a permanent magnet brushed motor, which produce signifigantly more EMF than brushless motors. All motors inside your PC case are brushless, case fans, HDDs, etc. On a brushed motor, the sparking on the commutator causes a ton of dirty noise.

Spinning magnets in general are a pain.

Moving your fan unit 5' from the monitor should eliminate it.

 

[TheNiceGuy]

Thank you! Very interesting.
I replaced the table with a new one that has only the heating elements installed. Much better. There was still a very slight distortion, so I tried the plug in a different room, and it dissapeared. If there is any distortion, I can't notice it now. Much better! This one pulls 500W/100V, and the fan version probably pulled more. BTW: is there an easy way to shield this kind of thing?

Learn something new everyday. Thanks again - TNG

 

[TitanDiddly]

You may still be getting some of that distortion that's there, but you won't know it until it's gone. You can probably eliminate this by degaussing your monitor. Your manual can tell you, or you can look around in the OSD.As far as shielding, there's not a lot that you can do on 'dirty' devices like heaters. You can get a Ferrite to put on the cord, this may reduce some of the bad stuff flowing back into the wall. Online is your best bet for ferrites, I've scrounged all mine from old equipment. You'll want a clamp-on one. That's all I can think of for 'easy' ways.

Hope that helps!

 

[canadageek]

as far as i know, being encased in aluminium /steel blocks
(electro)magnetism.try sticking a magnet to a piece of steel, then try to stick the side with steel to the fridge

 

[jagec]

It is worth noting that magnetic "shielding" doesn't involve blocking so much as redirecting magnetic fields. So you use something that's very magnetically permeable.

 

[JerryThomas]

question: My wife constantly has "strange issues" with her laptop. She uses her laptop sitting on an electric heating/vibrating/pulsating heating pad... could this be some of the issues???

 

[mindless1]

The magnetic field from the fan is only strong enough to affect the monitor, "maybe" a floppy disc or magnetic tape cassette if held right up against it.

The question on my mind is why are you using a 22" CRT monitor in 2017?

 

[Red Squirrel]

A CRT basically works on the principle of shooting magnetic fields in a X/Y configuration very fast to produce an image, so when another magnetic field is present it will skew the image, and it may even induce magnetism that causes semi permanent damage. Degaussing will fix this. This is not an issue with LCD though. Hard drives are suseptable to magnetic fields too though they do have some shielding. A powerful enough magnet near one will cause damage though. There are powerful magnets inside the hard drive used for the head movement, if those magnets are put near the platter area they will cause damage. Well, more like kill the drive completely. I can confirm this because of science I have performed myself.

As far as the rest of the electronics, a fast moving magnetic field could in theory induce voltages in the traces of the PCB that could cause issues. Most digital circuits will probably have some form of error correction built in to the communication protocols between chips and will also use pull down/up resistors that should be able to clear any induced voltages as the current will be very low. So simply having a magnet near a circuit probably won't do much, but a fast moving one such as a motor could. I think it would take quite a powerful magnet to really cause an issue though.

 

[Mr Evil]

...The question on my mind is why are you using a 22" CRT monitor in 2017?

Some sort of temporal anomaly has taken place. We should be careful what we say to OP, as he's probably confused by the sudden jump from 2004 to 2017. I expect right now he's struggling to find somewhere to plug in his AGP graphics card, and wondering what happened to MySpace.

 

[Mike64]

As entertaining as it could conceivably get, it's worth noting - before the thread gets even sillier than usual () - that the actual OP last posted to this thread 12.75 years ago, and that some poor unsuspecting brand new forum-newbie resurrected the sun-bleached bones of the thread to ask a question (in post #10) that I guess he thought seemed related? To wit:

question: My wife constantly has "strange issues" with her laptop. She uses her laptop sitting on an electric heating/vibrating/pulsating heating pad... could this be some of the issues???

My answer to his question is a short and sweet "no chance", but what do I know (excepting of course: how to read dates in standard US format... <g,d&r>)

 

[Mike64]

question: My wife constantly has "strange issues" with her laptop. She uses her laptop sitting on an electric heating/vibrating/pulsating heating pad... could this be some of the issues???

PS: If you're still around, you'll get more helpful advice if you post a (much) more detailed version of this question in the "Computer Help" sub-forum. Specifically, what brand and model laptop is it, what operating system and version does it use, and what, as specifically as possible, do you mean by "strange issues"? What exactly is happening, when she's using what software?