Often users are wary of magnets lying near electronics. Someone told us, or we saw for ourselves: these things can easily distort the image, or even permanently break expensive gadgets. But is the threat really that big?
Imagine the situation: magnets were bought as a gift for a child. In less than an hour, these things are near the computer, near the smartphone, near the TV ... Many months of dad's salary is under threat. The father of the family selects the "magnets" and throws them on the far shelf, but then he thinks: maybe not everything is so scary?
This is exactly what happened to DigitalTrends journalist Simon Hill. For the search for truth, he decided to turn to experts.
Matt Newby, first4magnets:
“People have such ideas from old electronic devices - for example, CRT monitors and televisions, which were sensitive to magnetic fields. If you place a strong magnet near one of these devices, you could distort the image. Fortunately, modern TVs and monitors are not so sensitive.”
What about smartphones?
“The vast majority of magnets that you come across every day, even some of the very strong ones, will not adversely affect your smartphone. In fact, it also contains several very small magnets at once, which are responsible for important functions. For example, wireless magnetic induction charging is used.”
But it's too early to relax. Matt warns that magnetic fields can still interfere with some sensors, such as the digital compass and magnetometer. And if you bring a strong magnet to your smartphone, the steel components will be magnetized. They will become weak magnets and prevent the compass from being properly calibrated.
Don't use a compass and think it doesn't concern you? The problem is that other, sometimes very necessary applications need it. For example, Google Maps compass is required in order to determine the orientation of the smartphone in space. It is also needed in dynamic games. For owners of the latest iPhone models, magnets can even interfere with taking pictures - after all, the smartphone uses optical image stabilization. Therefore, Apple does not recommend official case makers to include magnets and metal components in their products.
Next up are hard drives.
The idea that magnets simply destroy the contents of the HDD is still very popular today. Suffice it to recall an episode from the cult series Breaking Bad, where the main character Walter White destroys digital dirt on himself with a huge electromagnet. Matt speaks again:
“Magnetically recorded data can be damaged by magnets—this includes things like cassette tapes, floppy disks, VHS tapes, and plastic cards.”
And yet - is it possible that the character of Bryan Cranston did in real life?
“It is theoretically possible to damage a hard drive with an incredibly strong magnet if you bring it directly to the surface of the drive. But hard drives have neodymium magnets in them... a normal size magnet won't hurt them. For example, if you attach magnets to the outside of your PC's system unit, it will have no effect on the hard drive."
And if your laptop or PC runs on an SSD, there is nothing to worry about at all:
"Flash drives and SSDs are not affected by even strong static magnetic fields."
We are surrounded by magnets at home, says the expert. They are used in every computer, speaker, TV, motor, smartphone. Modern life without them would be simply impossible.
Perhaps the main danger posed by strong neodymium magnets is the danger of being swallowed by a young child. If you swallow several at once, they will be attracted to each other through the walls of the intestines, Matt warns. Accordingly, the child cannot avoid peritonitis (inflammation of the abdominal cavity - ed.), and, therefore, immediate surgical intervention.
HDD hard drives as an important and familiar carrier of information, it has one unpleasant property, it is short-lived. And after the failure, it is completely useless. Most often, it ends up in the trash, or deliberately scrapped for recycling, which in our country is considered completely meaningless for a number of reasons, but the main one is the lack of a clear and widespread mechanism for recycling and separate waste collection. This topic is for a separate discussion, perhaps we will return to it. In the meantime, we find application in everyday life, because taking something apart is always interesting for an inquisitive mind! You can show the children the device of modern disks and have an “interesting” time.
How can we benefit from a non-performing drive? The only use that came to my mind was to get neodymium magnets out of it, which are known for their magnetizing strength and high resistance to demagnetization.
The process of disassembling and extracting magnets.
With a tool, this is not at all difficult to do, especially since the disk is ready to fulfill its final purpose.
We will need:
- Screwdriver six-pointed star (T6, T7… depending on the model).
- Thin flathead screwdriver or strong knife.
- Pliers.
I have a WD 3.5 inch hard drive that has served me faithfully for 4 years.
We unscrew the screws around the perimeter, but the casing will not open just like that, another one is hidden under the sticker. Apparently, this is such a seal, it is quite difficult to find it. The hidden screw is located on the axis of the magnetic heads (I marked it with a red circle in the photo), and in this area there is a hidden fastener. But you can not stand on ceremony, because we only need magnets, the rest has no value. You should get something similar, one or two metal plates with magnets. With the help of pliers and some effort, we bend the metal plate and carefully pry off the magnets. I was lucky, the plate turned out to be flat, and I glued it with super glue to the shelf on the desktop. The tool is at hand, it does not dangle on the table, and most importantly, we gave a second life to some part of the hard drive. I think everyone will find a use for magnets in everyday life.
I work in a service center, where there are dead screws, well, they just filled up. All screwdrivers hang on magnets, conveniently, at the same time they are magnetized. Raz successfully used it to retrieve the keys that had fallen down the elevator shaft. But he did not come up with specific applications. And it doesn’t matter who you are and who she is, it affects any girl.
Separating the magnet itself from the metal plate can be very difficult at times. It's very easy to cut your hand. In the photo above, you can see the already separated magnet.
To separate the magnets from the metal plate, I pry the magnet from below with a knife blade. I just ask you - be careful! With the help of pliers and some effort, we bend the metal plate and carefully pry off the magnets. The coil is now protected from damage on one side with adhesive tape, on the other - with a ruler. The conclusions of the coil that go to the oscilloscope must be twisted so that there is less interference.
We need more powerful magnets, I bought it on ebay for a friend of mine from Moscow. Two magnets are packed so that between them there are 10 centimeters of foam. If you connect together, then you will tear off the horseradish force of 300 kg. BUT now put antimagnetic seals. We do not throw it away either, it is perfectly polished and will come in handy someday.
I remind you!!! Permanent magnets are afraid of strong heat!! And especially - sharp heating! Therefore, when cutting, they MUST be cooled! I just put a container with water next to it, and periodically lowered the magnet into the water after I made a small incision. So, the magnets are cut off.
We unscrew the screws around the perimeter, but the casing will not open just like that, another one is hidden under the sticker. Apparently, this is such a seal, it is quite difficult to find it. The hidden screw is located on the axis of the magnetic heads (I marked it with a red circle in the photo), and in this area there is a hidden fastener. But you can not stand on ceremony, because we only need magnets, the rest has no value. You should get something similar, one or two metal plates with magnets. Please note that initially it may seem that the plates are twisted, glued, or somehow fixed to the other.
I remind you!!! Permanent magnets are afraid of strong heat!! These are very strong magnets! But here one problem arose: the magnets, having a curved shape, do not fit in the width of my plate ....
How to separate a magnet from a hard drive
Hard magnets are a thing. At work, a thick thermally insulated door leads to my laboratory. Closes with difficulty due to weight and elastic seals. I had to constantly close the latch. It is only necessary to rest very strongly on the head of the screw and slowly scroll it.
"Destroying Myths" - this section is dedicated to the most common myths that have taken root in the world of information technology. The editors of the CHIP test lab will help you distinguish fiction from truth.
Many people believe that if a regular magnet gets close to a computer or hard drive, data will be lost.
Truth.
This opinion spread when 5.25-inch and 3.5-inch floppy disks were widely used. Magnets really shouldn’t be brought close to these storage media: even a distance of three centimeters was enough to destroy all the data. However, even neodymium magnets with a powerful magnetic field do not pose any danger to hard drives. Modern hard drives with a capacity of 1 TB or more consist of two to four plates coated with a magnetic layer based on iron oxide and cobalt. Information on the plates is located in small areas (domains) of the disk, which can have two states of magnetization - 0 or 1. Bits of information on modern HDDs are stored in vertical domains. This method, called perpendicular recording, allows you to save up to 19 GB of information per square centimeter.
Magnetic fields Reading and writing data to the HDD is done by moving the head over the platter at a distance of only 10 nm. This element works as an electromagnet and creates a strong field, under the influence of which the domains are magnetized.
Thus, it is magnetic fields that make it possible to write or erase information in domains.
But why then does an ordinary magnet not pose any danger? The fact is that the plates are so strongly magnetized that only very powerful fields with an induction over 0.5 Tesla can negatively affect the operation of the HDD. Since the strength of the magnetic field decreases with distance from the object, already at a distance of a few millimeters it drops to a negligible value. Therefore, the magnets brought to the HDD are too weak to affect the information stored on the hard disk.
Even a neodymium magnet with an adhesive force of 200 kg at a distance of 10 mm from an object creates a field with a magnetic induction equal to only 0.3 Tesla. However, it should be understood that if a magnet is brought near a working hard disk, it can deflect the read / write head to the side or cause it to touch the platter. This is fraught with write errors and, consequently, data loss.
In the photo - not all! Only those that I "sentenced" when I conceived this homemade product!
Some are out of order. Others are simply outdated. (By the way, there is a general downward trend in quality: modern hard drives fail quite often. The old ones, for one or two gigabytes (or even much less), are all in good condition !!! But you can’t use them anymore - they have very little the speed of reading information ... And there is very little memory in them.So it's not worth it.
But throw away - the hand does not rise! And I often wondered what could be made of them, or how to use them...
On the web, on request "... from a hard drive" are mostly "super talented" ideas for creating a grindstone !!! The people with a serious look show how to cut the case, glue the disk itself with sandpaper, and make a super-cool grindstone, powered by a computer power supply, and using its own hard drive motor!
I haven't tried it... But, I think, it will be possible to sharpen on such a grinder..... well, maybe, nails!.... And even then, if you don't press hard!!
And now, when I did, I remembered that there are powerful neodymium magnets in hard drives. And since during welding work "there are not many squares", then, at the end of the last home-made work, I immediately dismantled one of the hard drives to see what can be operated on)))
The magnet (I pointed to it with a red arrow) is glued to a metal bracket, which, in turn, is fixed with a screw.
In old hard drives, the magnet was one and more massive. The new ones have two. The second one is below:
Here's what I got after disassembling my disks:
By the way, the discs themselves also interested me. If anyone has any ideas for using them, please share in the comments...
To begin with, I decided to search the net to see if anyone had already invented this method of making welding corners?!)))
It turned out yes! They have already made these adaptations from hard drives! But there, a person simply placed a wooden board between the metal plates, to which he screwed magnets with screws. I immediately rejected this method for several reasons:
Firstly, the combination "arc welding + wood" is not very good!
Secondly, at the ends of these squares, a rather complex shape is obtained. And it will be very difficult to clean them! And he will take on a lot. Here is an example of a photo from my last post. They have a weak magnet on them, and he, after lying down on a workbench where they worked with metal:
And thirdly, I did not like that the square is obtained with very wide ends. That is, when welding some structures, the components of which are narrower than itself, it cannot be used.
Therefore, I decided to go the other way. To make, as with the "wooden" case, not the template plates of the body, but the end itself between them, but make this end smooth and closed.
In a previous publication, I already wrote that all magnets have poles, which, as a rule, are on wide planes for permanent magnets. It is not desirable to "close" these poles with a magnetic material, so this time I decided to make the side plates of the case from a non-magnetic material, and the end plate from a magnetic one! That is, "exactly the opposite")))
So what I needed:
1. Neodymium magnets from old computer hard drives.
2. Plate made of "non-magnetic" stainless steel (for the case).
3. Thin magnetic steel.
4. Blind rivets.
First of all, I took up the manufacture of the case. I had just such a piece of stainless steel sheet. (I don't know the brand, but steel doesn't stick to a magnet).
With the help of a locksmith's square, I measured and cut out two right-angled triangles with a grinder:
In them, I also cut off the corners (I forgot to photograph this process). Why cut the corners, I already said - so as not to interfere with welding.
I did the exact adjustment of the corners manually on a piece of emery cloth spread over the plane of a wide profile pipe:
From time to time I put the blanks into the square and looked "at the light". After the corners were taken out, I drilled holes for the rivets, connected the plates through them with M5 screws, and checked the corners again! (The requirements for accuracy here are very high, and when drilling holes, I could make an error).
Next, I started making the magnetic plate itself, which, as I said, I want to place at the end of my square. I decided to make the thickness of the square 20 mm. Considering that the side plates are 2 mm thick, the end plate should be 16 mm wide.
To make it, I needed a thin metal with good magnetic properties. I found it in the case from a faulty computer power supply:
Straightening it, I cut out a strip, 16 millimeters wide:
It is on it that the magnets will be placed. But here one problem arose: the magnets, having a curved shape, do not fit in the width of my plate....
(A little about the magnets themselves. Unlike acoustic speakers, hard drives do not use ferrite, but the so-called neodymium magnets. They have a much higher magnetic force. But, at the same time, they are more fragile - although they They look like all-metal, they are made of sintered powder of rare earth metals, and they break very easily.
I did not peel off the magnets from the steel plates - I only need one working plane from them. I just cut off the protruding plates with a grinder, and, a little, the magnets themselves.
In this case, a conventional abrasive wheel (for steel) is used. Rare earth metals tend to ignite spontaneously in air in a highly crushed state. Therefore, do not be alarmed - the "fireworks" of sparks will be much stronger than expected.
I remind you!!!
Permanent magnets are afraid of strong heat!! And especially - sharp heating! Therefore, when cutting, they MUST be cooled!
I just put a container of water next to it, and periodically lowered the magnet into the water after I made a small incision.
So the magnets are cut off. Now they are placed on the strip.
Having inserted long M5 screws into the holes for rivets, and securing them with nuts, I bent the following complex structure along the perimeter of the template plate:
It is on it that the magnets will be located inside.
