When I was growing up, you had to keep magnets away from computers and other electronics. Magnets could single-handedly wipe drive and disk, and could play havoc with cables transmitting data. It was generally taught to me that these two should not be mixed with, barring the proper housing. However, magnets are everywhere with modern electronics and computers and it’s something that has been quietly puzzling me for quite some time now. Please someone, explain how this can be. I know there is a very simple answer to it, but my brain can’t conceptualize it.
In: 10
Old electronics used their own magnets to create magnetic fields. These fields need to be very precisely controlled to ensure correct operation and avoid damage. Outside magnets could overpower this control, disrupting or damaging things.
Specifically, hard drives and floppy drives work by moving little magnets in a physical disk using an electromagnet in the drive. Then, these drives read the magnets. An outside magnet, can force these little magnets to flip the wrong way, or overload the reader.
Furthermore, CRT screens use magnets to steer a beam of electrons into very specific places. Overpowering this magnet, will send the electrons off course. What’s worse, if the CRT contains ferromagnetic metal, it can be magnetized, causing the disruption to become permanent
Modern electronics simply don’t use the same sort of sensitive equipment. Hard drives are much better protected from magnets these days, and floppy drives and CRT’s are basically novelties.
And the rest of the computer doesn’t care. Computer chips use electricity, not magnetism. You can create electricity with magnetism, but this requires putting in energy. For modern devices, it takes a *lot* of energy. So much that it’s genuinely somewhat difficult even if you’re trying to break something, and an accident is basically impossible for a typical home user.
Now, as for long wires: magnets *can* interfere with signals. Any wire is an antenna. And any moving magnet, is a radio transmitter. Old electronics were analog – the accidental radio signal gets added to whatever you are trying to transmit, and the receiver can’t tell them apart, so it gets a distorted signal.
Digital electronics are much more resistant to this. Digital signals are created by switching the voltage in a wire. The reader measures the voltage, and if it’s in one range it reads ‘1’, and otherwise it reads ‘0’. As long as the signal picked up by the wire isn’t enough to push the data signal out of its intended range, the receiver doesn’t care.
More importantly: if you have two wires next to each other, they will pick up almost identical radio signals. And modern receivers compare the two signals to each other, so they flat-out don’t notice if both signals are distorted identically.
Further, it’s pretty easy to outright block these signals from reaching your wires. All you have to do, is surround them in a metal shield. The shield absorbs the magnetism, keeping it away from the actual signal wires inside.
You can still flat-out damage electronics like this, but once again, it takes so much energy that you’re not gonna do it accidentally with household materials.
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