How do these Magnetizer/Demagnetizers work?
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- Опубліковано 3 жов 2024
- These cheap screwdriver magnetizer/demagnetizers are amazingly effective. In the video, we look at how to use them and how they actually work. And most importantly, solve the mystery about what the staircase in the demagnetizer section is actually for.
They are more effective than I judged they have a right to be. You'd expect the magnetizer to not really magnetize and the demagnetizer to not really demagnetize but what you get is something that is very effective at both. So its not transferring anything to the screwdriver, its just lining up existing magnetic domains within the steel or partially randomizing them. A very cool and handy piece of kit, even the super cheap ones.
Exactly what I thought - amazing little devices. I wish I knew who came up with the ingenious designs that so cheap and yet so effective.
@@ElectromagneticVideos
One should be able to make their own? - crudely or with a nice 3D printed case.
@@djmipsTrue but this is probably one of the few things it’s cheaper to just buy lol - it’s hard to beat $3 at a local walmart or $1 on Temu, vs the costs for the pla, electricity, magnets, and your time
@@ElectromagneticVideosThe earliest one I found was a patent in 1967 by Cloyd D Smith (US3467926A)!
@@djmips Yes - the hardest though would be to find a suitably shaped magnet.
The drawing was very helpful for understanding how the demagnetiser works.
I glad it helped - I always find a diagram makes things easier to understand or visualize.
Indeed.
Diagrams are the most effective way for me to learn something. He’s very good with this!
I bought one of those and found it really works. Didn't get detailed instructions on how to use it. Now I know thanks to your posting this. Thanks for your help!
Your welcome! Glad the video helped!
Can you tell me where I can buy one of those magnetizers/demagnetizers? I live in an extremely rural area and we don't have the luxury of having any of those types of things. We do have a hardware store but he never heard of anything like that??
@@scorpio5493 Aliexpress, Temu, Amazon, ebay - they all sell the same China stuff.
It seems so simple when the construction is revealed. I always wondered how these things worked.
I think I referred to it as "magical" in the video and it is! It did take a me a while to clue in what the steps were for.
The first thing I did, after seeing it work, was break it open 😅
@@assasin19991999 Its so intriguing its hard not to do that :)
Putting the bar magnet on a gimble was genius for clearing showing field orientation. Great video!
Glad you liked it. Those field direction indicators area really great for demonstrations.
Really excellent video, thank you for this clear explanation. About 5 years ago, I bought a screwdriver set with one of these magnetic devices built into the storage rack, and until 15 minutes ago had no idea how to use it! I'm off to the garage NOW to try it 😄
Thanks again, I've liked and subscribed!
Well thank you so much! It is an intriguing little device with way more clever magnetics than one might at first expect.
So glad you subscribed - I really appreciate it - always important for a small channel. Hope you enjoy some of my old - and future videos!
I’ve literally always wondered what they point for the stairs were. I thought it could be just a quick visual indicator of what side you were about to use.
Now I need to go try this myself! Thanks! 😊
I few other people have said that and I think its secondary purpose is as an easy indicator. Really good ergonomics from that standpoint.
Really appreciated this video, so I figured I’d leave this comment to hopefully help this video in the UA-cam algorithm.
Thank you so much!!!!! Yes - leaving comments really helps - really appreciate you - and everyone one else who comments - doing that!
Informative! This reminds me of the AC powered tape head degausser wand/tool I bought years ago. The instructions were that the tip of the degausser was to be moved away from the tape heads slowly. The steps on that magnetizer/demagnetizer block make sense now.
I have an AC powered bulk tape degausser and also one for CRTs - very similar in terms of moving away slowly. I did a video on that if you interested: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
More spectacular was the degaussing coil for a CRT, you rotated it in front of the tube watching the lovely colour patterns whilst slowly move some meters away. If the power was shut of too quick the tube had a permeant field and that was not good. Also the mains coil pulled a good few amps so you had one shot at it before smoke appeared.
Had one for decades but never knew it worked that fast and didn’t know about the stairs. Always just left it in over night not knowing. Thanks.
Your welcome! Others have thought that running it though the magnetize section a few times would help. Its too bad most or all don't come with instructions.
Never even heard of such a device like this before. It’s pretty awesome and I wouldn’t mind having one here in the house. Plenty of times when I had to try and keep very small screws on a screwdriver which was not magnetic. This would solve that issue
Most hardware stores and online retailers have them ranging in price from $3 to $20. I used the $3 or $4 ones. Well worth having one at that price!
Thank you! I love that thing and always wondered why it worked and what those steps were for. "Now I know! AND KNOWING IS HALF OF THE BATTLE!"
"KNOWING IS HALF OF THE BATTLE!" So true for so many things. What I like about this device is how impossible it seems until you open it up, and them its almost obvious. The investor(s) who came it with it years ago was so smart and really knew magnetics!
It would be nice if you used your detector on the screwdriver during the last demonstration with the disassembled demagnetizer. Thanks so much for actually taking apart the demagnetizer!!
You know, its always a struggle as to how long - or short to make a video, and the youtube audience seems to have a short attention span. So unfortunately many things that could be in it get left out .... Glad you like seeing the actual inside of the device!
I have precisely the same magnetizer, and I always wondered what's the function of those stairs. Now I know, thanks.
Your welcome! I took me a while to figure out the purpose of the steps. I suspect decades ago there was an instruction manual with the first version of the device describing how to use it, but somehow over time that information got forgotten.
Nice explanation of how these devices work. I taught biology in college and would have loved it had I been able to put together such a nice, concise lesson. Usually I just rambled around a topic until my students either figured it on their own or were totally lost.
One trick which you dont have in a classroom is the ability to edit! You wouldnt believe how much stuff I edit out!
I have one of these but the markings wore off of it a long time ago and I had forgotten which one was mag and demag. I also never knew what the stairs were for. Much appreciated explanation.
You must have an old one! So far, I have not found out when the stairs first appeared - looks like the original did not have them. Its too bad that none seem to have an explanation of what the stairs are for.
I have some speaker magnets on my bench and i use them to magnetize my screwdrivers, and it works like a charm!❤
You cant beat speaker magnets - they are some of the best - probably work better than the gizmo in the video too.
What a great teacher you are, Thank you!!
Thanks again!
I have shown using these handy devices many times on my bench and it's really great to see inside and learn the science behind it. Excellent video as always! I Enjoyed it! Thanks.
Thank You! Yes - amazing cheap, simple devices that are so effective!
I use that exact kind of one every time I use a new screwdriver. I love it lol.
Great little tool!
I really appreciate this! I acquired one of these many years ago in a box of tools, and I’ve never really played with it..
Glad you liked the video. Those little devices are great to have in a toolbox for that one time you need to pick up hard to reach screw, or for that matter when a screwdrivers is annoyingly magnetized.
Thank you. I always assumed there was more to these little tools than that. Looked up my old mag'r/dem'r and used it with new understanding. Mine does not have the steps, but rather, has a "D" shaped demag area with the curve facing downwards. Magn'tzd a driver, then put it in the demag at the bottom and slid it up to the top while withdrawing and it worked perfectly.
Your welcome! I haven't come across one like you describe, but it sound like a similar process - gradually reducing a changing magnetic field as the screwdriver is pulled though the demagnetizer. I'll have to keep my eyes ope for one like you describe!
5:58 this is where Technology Connections would cite "by the magic of buying two of them..."
Your not the first one who pointed out I was negligent in not saying that :)
Some times the more simplest things really do amazing jobs very well... Thumbs Up!
I couldn't have said that better myself. An amazingly ingenious little device!
I was given one of these way back in the '90's. First time I used, it was a wow moment. Pretty clever device that doesn't cost the earth..
I have been wondering when these devices first appeared - so thanks to you I now know they were available in the 90s. Will be interesting to see if anyone mentions having one earlier than that.
@@ElectromagneticVideos I bought one in the first half of the 2000's, but was aware of their existence about 5 years or so prior. That puts my earliest spotting of them in the latter half of the 1990's, coinciding with the account of @bertiesworld .
Clear, informative, concise -- well presented! I learned everything one needs to know about this device -- thanks!
Thanks so much! Glad you found the video useful!
Agree here, it gives the information you need in a straightforward and direct manner.
Though,
I wouldn't be disrespectful towards those who prefer a different video style since it'll come down to viewer preference.
I have wondered how these work. I debated buying one just to open up, but I wasn't that curious. Glad you made this video
Glad I did - seems like I save a number of these gizmos from being chopped up!
I have a identical one, very handy.
Thanks for clearing up the mystery.
Your welcome! It was fun figuring out how they work!
been using these things for decades and i never really considered WHY. thank you so much! :D
Your very welcome! It is a really clever little device.
I’ve used these for decades. Great tool! It works!
Yes - so handy to have when you need it!
your voice is very relaxing and this video was very informative. thank you!
Thank you! First time a comment told me my voice was relaxing :)
@@ElectromagneticVideosvery true!
@@glottalstop2080 I'm amazed!
It's called ASMR :)
@@sprockkets :)
When I was in school, we did this with bare magnets; stroke a magnet longways down the shaft, physically touching, to magnetize, stroke through the air further and further away to demagnetize. Basically the same principle, but without a gadget.
Yes - exactly! I vividly remember doing that in school too. Seemed amazing at the time. And it sort of still is!
Great explanation and demonstration. I always expected that you would need an active electromagnet with AC input for a good demagnetizer but obviously the simple setup in this device resulted in very good demagnetization.
Thanks! That's what I thought till I looked into the ingenious little device. I'm not sure how well I explained it in the video, but as you pull the screwdriver out of the demagnetizer each part of it is exposed to a magnetic field that changes direction as it weakens. The effect on the magnetic domains in the steel is much like an AC field, and moving up the steps is like gradually moving the object away from an AC demagnetizer.
@@ElectromagneticVideos I think the video was clear and I understood it like you described here. I was simply surprised that such a simple method worked so effectively.
Good video that mate, you have a good voice and demeanor for youtube videos like this.
Well thank you so much! Glad you liked the video - and my voice :)
I use one of these for my work fixing/ servicing laser printers/ MFDs in an enterprise environment and this simple device makes my work a lot less stressful!
Interesting - never thought about it but the laser printers etc you work on are probably the most mechanically intricate piece of equipment used in homes and offices. With all the screws and tiny parts I can imagine how this little device would be useful for that.
My first experiment with magnatism (even though I wasn't aware of it as such at the time) was as a very small child, when I put a magnet onto the screen of our home CRT colour television. So enraptured was I by the effect (all those pretty colours in rainbow arcs) that I drew attention to the spectacle to my mother, who told me to 'stop doing that immediately' - I'm paraphrasing.
😂
Ha! Me too actually. But both you and me were lucky - one commenter did the same but either had too strong a magnet or held it too close and apparently permanently magnetized the some part of the tube (shadow mask maybe?). Apparently none of the TV repair shops could fix the color shift and the TV had to be replaced - oops!
It was a very viewer friendly explanation. The simple device is really cool. I wonder if I could make one 🤔. To make the the sweet spot it would take a precise adjustment though, buying it would be better for a proper use tough.
Thats - "viewer friendly explanation" is always what I aim for!
I think getting magnets of a convenient size might be the biggest challenge. Some commenters have suggested neodymium magnets. If you held them around the magnetizer hole region at a point where they begin to repel, thats probably close to the sweet spot...
You cant fool me, magnets are just magic
And this gizmo sure proves it :)
"Fuckin' magnets, how do they work?"
-ICP 2010
@@curtisyue182 beat me to it, damnit
Electromagnetism as a whole is just magic we understand. It's got some awesome powers.
@@thegenericnerd3189 It sure does some magical things! Sadly because of its complexity, Maxwell never got know they way Newton or Einstein did after figuring out the classical theory behined it.
Very detailed and high quality content! Thank you!
Thanks! I appreciate the compliment!
As a teen in the 70's I remember my dad using his Weller soldering gun to magnetize his screwdrivers. He would wrap several loops of copper wire around a broom handle and connect the ends to the gun. Remove the broom handle, pull the trigger, slide the screw driver inside the coil, and voilà the tool was magnetized. I wonder if your magnetizer tool existed back then!? 🤔
What a neat memory. The trick with magnetizing things that way is to turn the gun off while the AC field is at its peak so it leaves a string field in the screwdriver. Leave it on and pull the screwdriver away gradually and you can demagnetize the the screwdriver. I did a video that includes a Weller soldering gun doing just that here: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
You know, I would be so interested to know when someone invented this little device. My guess is 1960s is the earliest it could have been developed because thats when plastics became in widespread use making it simple to manufacture. If anyone knows when they first appeared, or what company made the first one, please post!
Really clear and logical. Thanks for explaining ❤
Your very welcome! Glad you found it clear and logical - thats what I always try for!
This & computers are magic.
You can't convince me otherwise
Certainly seems like that at times!
Hello, Dr. Jones. Thank you very much for the fast reply. You got a new subsciber !!
Kind regards from Tenerife/Canary Islands.
Wow - the Canary Islands! Thats a first for my channel! I have a large number of viewers in continental Europe, but until now didnt know anyone from the Canary Islands was watching. The Canary Islands have always been on my bucket list of places I would like to visit - looks like a wonderful place. Well welcome to my channel - hope you enjoy some of my old - and future - video!
Hello, Dr. Jones. Your channel is very interesting to me as I am interested in electronics. I have also learned it.
The Canary Islands are a bit like your background image "Hawaii".
Here in the south it is always warm all year round. 25-35 Degrees, never below 20 degrees at night. Very little rain!
The water is turquoise to dark blue and very clear. Important: No sharks! Only turtles, dolphins and whales.
Your right decision to come here.
And then you are my VIP!
For an impression, have a look here:
skylinewebcams, then canaries, then tenerife.
Sunny greetings@@ElectromagneticVideos
@@ElectromagneticVideos Hello, Dr. Jones. Your channel is very interesting to me as I am interested in electronics. I have also learned it.
The Canary Islands are a bit like your background image "Hawaii".
Here in the south it is always warm all year round. 25-35 Degrees, never below 20 degrees at night. Very little rain!
The water is turquoise to dark blue and very clear. Important: No sharks! Only turtles, dolphins and whales.
Your right decision to come here.
And then you are my VIP!
@@pennylane8859 It sounds a bit warmer than Hawaii, and not as much rain. I was always fascinated by the Canary Islands after reading about them as a kid, probably in an old National Geographic. One of my friends took his family to one of your Islands a few years ago for winter vacation (Canadians like to go somewhere warm in the middle of the winter) and really liked it. No sharks is always a good thing! Who knows, maybe in a few years - see you then :)
You re welcome, Dr. Jones @@ElectromagneticVideos
Had been wondering about this, thank you for the wonderful explanation!
Thank you! So glad you found the explanation wonderful!
I feel like you could of mentioned the difference it makes if you have a hardened steel, from the screwdriver, vs untempered soft steel, on magnetization. PS I love the simplicity of the device. Thanks for the explanation👍
I get your point - but I'm sure you have also found that it is always a tough call as to what to put in a video and what to leave out. I find that the attention span of the general youtube audience is such that often keeping things to a minimum is better and so I purposely left out the aspects of different magnetic materials.
A while back I did do a couple videos about magnetization in case your interested:
Magnetizing: ua-cam.com/video/S21rlwrY74I/v-deo.html
DeMagentizing: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
Just looked at your channel (actually just subscribed). see your from the UK. Regards from Canada!
@@ElectromagneticVideos I know what you mean, I have definitely made the made mistake of adding too much information in my older videos🤔. It's finding the right balance of getting your message across(and keeping attention spans) without compromising too much. Thanks for subscribing👍😉
@@MyProjectBoxChannel Yeah - you wouldn't believe how much stuff I cut out of the final video before publishing. Well actually you probably do :) Anyway, looking forward to watching some of your videos!
I can't find which video now, but Technology Connections looked at these a while ago and didn't know what the staircase was for. Really some instructions should be supplied with these devices.
Its funny - based on some comments, these gizmos have been around for at least 30 years. They must be copied from the original manufactures product produced in the 90s or earlier (anyone know?). Looks to me like the copies of copies of copies that we get today are being produced by companies that have no idea how the product works, and certainly wouldn't likely have anyone with a background in magnetics on their staff. After all they just make an injection molded plastic housing and put some magnets that they get from some supplier inside. So I dont think the manufacturers today even know the purpose of the staircase. I did some googling and the only instructions I found was something like "put the screwdriver in the magnetize hole to magnetize it and in the other hole to demagnetize" which seems to confirm they dont know.
Very weird that its a product that even the manufacturers dont know how to properly use it!
This has the vibes of a Technology Connections video
I guess it does to some extent. It was really meant as one more of a series of videos I did about magnetics.
I have one of those exact magnetiser/demagnetisers, I always wanted to know, How? Now I know and understand how they work, thanks for that.
Your welcome! Glad I solved the mystery for you!
I've had one of these for many years and never really understood how, exactly, it worked.
It just did!
Many thanks for showing me. :)
Your welcome!!!!!!!
Very cool explanation. Maybe including one of those jars of oil with iron filings in them to show the fields around the tool would make the fields even more apparent.
Yes! Someone even pointed out that you can now get an even easier to use variant of that which is somehow made into a green flexible sheet. Next time!
Thanks, loved it, I have one, and a matching screwdriver, and screw jars like yours
Glad you enjoyed it. Actually I wish I had more jars that size - really handy for smaller quantities of screws.
@@ElectromagneticVideosI just use empty spice jars
@@orngjce223 great idea - they are the right size!
I just bought one of these after seeing your video !
I guess I should have cut some sort of a deal with the manufactures :)
Excellent video. I will be buying one!
If you can, test it in the store. A small number of people have reported getting one that didn't work, sometimes missing magnets. I suspect for the low prices these things sell for, quality control is minimal!
How exciting! I'm going to buy a bunch of these and hand them out to my friends!
Try one first - apparently some manufacturers versions of them don't work that well. And it doesn't seem to correlate to cost - the two I got were the $3 or $4 ones- the cheapest and worked fine.
Had problems demagnetizing completely . Now I know. Thanks alot. Others say that stairs doesn't do anything because it's empty inside and just for show. ;D That's youtube for you
In fairness to other youtubers , these devices don't seem to have instructions on how to use them, and to deduce why the staircase is needed does take a bit more than an elementary under standing of magnetics, although its pretty simple once you understand it.
Hope this solves your demagnetization issues. If not, see if you can find an old AC powered bulk tape demagnetizer which should be able to an even better job.
Just tried and this simple stairs solution helps. Sometimes it takes a couple of times but definitely works :)
@@christopherismcaceas4868 I found the same thing - I think it has a lot to do with positing the screwdriver just right for each step. If it dips down towards the magnet it can re-magnetize itself. Not a perfect device, but amazingly effective for its simplicity.
Before watching further:
My guess is that it has a series of alternating N and S poles that feet weaker and weaker the closer you get to the face of the device.
Gee - I should have said "stop the video and write down your best guess how it works". It is amazingly simple when you know how it works, but certainly not obvious just by looking at it!
The only way to really demagnetize a tool is to use a coil from an old solenoid valve. You only have about 30 seconds to do it because the coil will get hot, but i guarantee you that it will be totally demagnetize. 😁
Yes! This gizmo does a decent job but an AC field is really the way to do it. I did a video on that here: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
I have seen a video on this before but the guy kinda ignored the stairs saying they where just a design thing but you've given a far better developed version of that explanation thank you.
Your welcome! To be fair - its not obvious how the steps could be of use given they are non-magnetic plastic and none of these devices seem to come with proper instructions. It did take me a while to clue in that it was much like the operation of an AC powered demagnetizer: pulling the screwdriver out of the hole makes a AC-like rotating magnetic field, and moving up the steps makes that AC field reduce in strength for each cycle. If you want to see how a AC demagnetizer works, I did a video on it a while back: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
so, as a party trick, you could de-magnetize on the opposite side of the de-magneetizer hole - just moving the screwdriver in the free air ?
Yes - in other words, if the device is oriented so that that the demagnetizer hole is above the magnetizer hole, you can demagnetize by passing the screwdriver below the bottom side of the device (ie below the magnetizer hole).
Damn dude! I have one of these, and i never thought it worked this good! Like i knew it worked, but i think it is only good for a little bit if that makes sense. Like a short duration
Your exactly right - the steel in most screwdrivers is "soft" from a magnetic properties standpoint. So unlike magnetically hard materials used to make permanent magnets, its easy for a screwdriver to demagnetize. Often all it takes is banging it ageist something hard to loose most of its magnetism.
Thanks so much for this. I love learning how things work.
If you would, a question: Except when you used the demag staircase, you passed the screwdriver through only once. When I've magnetized screwdrivers with these devices, I've passed the screwdriver through multiple times, figuring that more is better, while keeping the same orientation of the shaft (i.e., not rotated). What effect do multiple passes actually accomplish, if anything?
Your most welcome! Thats a great question: If you look here ua-cam.com/video/AZsYHLHlIso/v-deo.htmlsi=YzF_NleqpT-YFHbm&t=291 , when the screwdriver is more than half way though the hole, that (far) end is subjected to a magnetic field going in the opposite direction (arrows pointing left in my diagram), magnetizing that end in the other direction. When you pull it back, the last strong field each part of the screwdriver sees is the fieldd with arrows pointing right, and since that is the last field it was subjected to, it retains that field.
So when you do multiple passes, any part of the screwdriver that goes though more than half way gets magnetized in the opposite direction undoing any magnetism it originally had, only to regain it when pull back out of the hole.
So in the end multiple times probably wont make much of a difference. There may be a slight effect (adding a bit more or less magnetism) depending on the slight positional changes every time you redo it. Hope that helps!
Makes perfect sense, now that you've explained. Your illustration indeed helps. Thank you. @@ElectromagneticVideos
Nice work
Thanks!!!
This is a clever device for how simple it is! I could sort of deduce how the magnetizer half worked, but I was totally stumped by the demagnetizer until you explained it.
I couldn't agree more! I was baffled by the demagnetizer - and even after figuring it out, the staircase was a mystery -even after googling it. Took me a while to clue in that it was mimicking an AC demagnetizer as discussed here ua-cam.com/video/mGK8oYdEqyE/v-deo.html
I use an old solenoid connected to AC when my tools need de magnetising.
That is a far better way to demagneitze and can achieve almost complete demagnetization. I did a video a while back on how that works if your interested: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
I love covering magnets with iron filings
I once went to far doing that - has an old loudspeaker magnet that I used as a string magnet. You can never get the iron filing out of the crack that the voice coil fits in!
Since the direction of the magnets is arbitrary, what if we magnetize and demagnetize the screwdriver using the same pole?
For example pass it through the magnetizer hole of one device, then pass it through the demagnetizer hole of adevice with opposite magnet direction. In both case the screwdriver will be exposed to the same "pole" with different field strength.
It will still work! The key is when it is inside the demagnetizer the field is perpendicular to the length of the screwdriver, which is magnetized in the long direction (because the last strong field it saw in the magnetizer was parallel to the screwdriver (see ua-cam.com/video/AZsYHLHlIso/v-deo.htmlsi=eaBRerMm-y76t-bC&t=285 ) . So The perpendicular field in the demagnetizer first magnetizes the screwdriver in a a perpendicular direction (regardless of the direction of the original magnetized direction). Now as the screwdriver is pulled out, the field it is exposed to gradually changes direction (towards the parallel orientation) and weakens. This change of direction and lowering of the strength simultaneously essentially magnetizes the screwdriver with a lower field strength. Repeated at the next step up you start with a lower perpendicular field and end with a much lower parallel field. So each pull one step up reduces the magnetization a bit more.
Hope that helps. I did a more detailed video on demagetization a while ago. If you interested, here it is: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
Very good!
Thanks you so much!
If I understand correctly, passing the screwdriver over the magnet at those three different heights, in that order, puts the iron of the screwdriver in a close-to-random configuration. The closer to random it is, the less iron shavings it picks up. The goal of the device is to take a magnetized piece of iron and make it as random as possible while keeping the cost of material low and the procedure quick and easy to reproduce. This device accomplishes both objectives well!
You described it better than I did! What a perfect summary!
If your interested in a more detailed look at demagnetization, which is normally done with an AC magnetic field field that is gradually lowered (and is similar to what happens during each pass of the screwdriver) , I did a video going into more detail a while back: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
Hi buddy, just came across this video, and wow, I never knew what the steps were for, mind blowing video Thankyou.
Keep up the great work mate, sub’d and liked, now going to watch the rest of your content. 🤙🏼🇦🇺
Joe from Australia 🤙🏼🇦🇺
Glad you liked it and thanks so much for subscribing! Australia - I spent two months exploring the eastern edge of your country a while back - what a wonderful place! Regards from Canada!
I have one of the exact ones myself, Fun part is that I wanted one to my job too and when we got one it was very light and it did not work either, funny thing is that it was a bad sample as they had somehow missed to include the magnets inside it lol. I got a new one that also worked
Poor quality control I guess :) A few others have mentioned getting one that didn't work - your the first reporting it was due to lack of magnets!
@@ElectromagneticVideos I guess the magnets “got stuck” in production
@@Pulverrostmannen Or maybe a machine inserts them and only a few thousand items later was it discovered :)
@@ElectromagneticVideos indeed, who knows what happened but I was pretty stoked about the result since I had one myself and I was like this is not right. It was like poking a screwdriver in mid air. Nothing happen or felt. It was just a plastic hole lol
@@Pulverrostmannen It must have been weird "how can this possibly work!?!?"
Thanks!
Your most welcome! Thanks for watching!
Isn't also true that you can hit the screwdriver against for example a big vice, like I tend to do to get rid of small metal filings? I've been wondering how that actually works.
Yes! Causing a mechanical shock like that will demagnetize things - not just tools but also "real" magnets, although magnets are often brittle and are likely to break in pieces if you hit them too hard. The steel in screwdrivers consists of tiny magnetic regions called domains. When magnetized, they re mostly lined up with their fields pointing in the same direction. Bang it and it shakes them up and they end up pointing in random directions on average and average magnetic field goes away. It works the other way to - expose a screwdriver to even a weak magnetic field and bang it, and it will re-arrange the domains and become magnetic.
Excellent, thanks ❤
Thank you!!!
This is kinda close to a magnetic monopole coming out that magnetizing side. I know it is not but it is interesting.
Your absolutely right with the flux field spewing out from the magnetizing hole. I'll have to remember that analogy, particularity if I do a video on the existence ( or lack of) of magnetic monopoles!
I find demagnetizing (or 'degaussing' as said in the biz) with these things to be a bit hit/miss. For that I have an old CRT TV degaussing coil in the shop that does an excellent job every time... additionally it's big enough for most hand tools, and can even be passed over bench vise jaws. Use 'technique' is important for degaussing coils. (Don't exceed their duty cycle limitations!)
Note that alloys used for screwdrivers make poor magnet materials... and they will never strongly magnetize.
Also, an old camping compass makes for an excellent detector of stray magnetism.
Well, you may like this video ua-cam.com/video/mGK8oYdEqyE/v-deo.html - I have a CRT degausser too! You are one of the few people I have come across who also still has a CRT degausser!
Compass - YES! I actually shot some of the video using a compass to determine the degree of magentization of the screwdriver (how far away to make the compass defect ever so slightly) - in the end decided iron filings made it more obvious in the video.
"And it's not attracting anything." I can relate screwdriver, I can relate.
:)
I got a demagnetizer that's over a hundred years old. It's a watchmakers tool. It's a coil of wire in a case with a switch that looks like a telegraph key to pulse it on.
You can really feel the pull of the magnetic field when you pulse the switch with something metal such as a file inside the coil.
This pull is probably where guys got the idea to build magnetic pulse guns.
What a cool vintage piece of equipment!
I did a video on coil type demagnetizers a while back in case your in interested: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
@@ElectromagneticVideos Look up "Vintage South Bend pocket watch demagnetizer" with a Google image search and you will see models like mine. They go for around $100 bucks as antiques these days.
so you could demagnetize the screwdriver by moving it below the whole thing as well? my brother showed me you can magnetize your tools by leaving them in strong sunlight too which works but I don't know why.
Yes! Exactly!
Materials loose their magnetic properties above a certain temperature called the Curie temperature. Heat a magnet above that and it will demagnetize. Works the other way too. Place some steel that is really hot in a magnetic field and cool it, and the steel will become magnetic.
what if i build one with hard drive magnets? is that gonna be even better?
It will depend on the geometry of the magnets and how strong they are. If you had a bunch of smaller ones you might be able to arrange then in a row with alternating polarity, with the row at an angle towards the screwdriver. That was as you pull the screwdriver out it would pass over a series of alternating fields, each one a bit further away, and reducing the magnetization a bit more. So with a bunch of old hard drive magnets you might be able to make a really good demagnetizer
Had a mate come around and he grabbed a tool out of my drawer and saw my mag/demag tool. I told what it did but he simply wouldn’t believe me. I showed him and his mind was deadset blown. Hilarious.
Thats funny. But it sure shows how amazing this type of little device is!
@@ElectromagneticVideos
Sorry, I forgot to say thanks for the good vid. 👍
@@michaelslee4336 No worries - thanks very much!
When you're trying to charge or decharged the screwdriver does it only need one pass or does multiple passes raise the effectiveness?
Magnetize: because of the magnetic flux splits and flows outward through both sides of the magnetize hole, more than one pass wont increase the strength.
Demagentize: the hard thing is keeping the screwdriver parallel to the floor of the demagentizer hole as you pull it though and move it up step by step. If you dont think it was parallel enough, a second pass at teh same step may help. But if it was parallel, it should make no difference. So I guess in summary, if you did it right, one pass is all you need at each level.
@@ElectromagneticVideos thank you for the detailed response. I have one of these in my toolbox and use it a lot, but I've always ran it through multiple times. Almost like sharpening a knife. Now I know I don't have to do that.
@@Big_Perm Well the important thing is in the end, whatever works!
I have seen those in stores, but never tried one. At my last job, we had an old ballast from a streetlight connected directly to 120 vac , with a momentary contact switch. If you were quick enough, you could magnetize with it. Hold the switch down and slowly move the screwdriver out of the coil to demagnetize...
If I see one of the gizmos you demonstrated, I'm going to get one and experiment with it...
Well done video.
Thanks!
How neat - what a great example of magnetizing and demagnetizing .
If its of interest to you, I did some videos a while back on how things get magnetized: ua-cam.com/video/S21rlwrY74I/v-deo.html and demagnetized: ua-cam.com/video/mGK8oYdEqyE/v-deo.html with a lot of similarity to what you describe.
Keep an eye open for one of those devices - some people even reported getting them free as part of some promotion!
There are "papers" that show magnets - they're often green, some of the "smart" magnets are fascinating!
Someone else mentioned that and I googled it. Will definitely have to get some. Thanks for pointing it out.
So, theoretically, you don't even need the top half of the demagnetizer or the steps, do you? If you flipped the whole thing upside-down and slowly raised the screwdriver up from it while moving it forwards and back repeatedly, would it not have the same effect as sticking it through the demagnetizer over each of the steps?
Yes - exactly!!!!!!!! The steps and demagnetization hole are only a convenience.
@@ElectromagneticVideos it's a very clever convenience, able to instruct you to do all of what I said just by giving you a hole with some steps on the side
@@badger273 Yes - I never expected the cheap little device to be such a brilliant design in its simplicity and functionality. Whoever came up with the steps (which was not in a 1960s patent for a similar device) must really have had in in-depth understanding of magnetism.
i have actually never seen those, i didn't even know they existed! Now i know i need one.
I'm sure my videos has inadvertently resulted in sales of thousands of these devices - to bad I don't get a royalty :) . They are so cheap and so useful to have its well worth picking up one if you happen to see one in a hardware store.
@@ElectromagneticVideos the only way i knew to magnetized something is to keep rubbing a magnet over and over (not so different from device), or wrap a coil around object and tap it to a car battery which is not always possible. To demagnetized i had no other way unless to super heat the object, again not always possible, this device makes all that easy!
@@ayumuchan3541 Yes! I really take my hat off to whoever came up with with such a simple mechanism to do it - particularity the demagnetizing part!
I would have never thought a cheap $5 piece of plastic and a few magnets would actually do what it claims to do. 🤯
This must be some old invention with an expired patent or people would be trying to charge $69.99
You could do a whole video series on cheap gadgets that are way more amazing than the price would lead you to believe.
One of the commenters said his dad invented it and I did find the patent from the 1960s. It didn't have the steps so someone must have come up with that later.
That's a great idea for a video series! I wonder how many little gizmos fall into this category - I will certainly be on the lookout for any. And any suggestions are welcome :)
Can you use that device to re-magnetize a de-magnetized magnet?
Unfortunately it wont work well for that. permanent magnets are made from material that is harder to magnetize (and therefor demagnetize) and typically needs a stronger field to magnetize than this device will produce.
I did a video on re-magnetizing permanents here if your interested: ua-cam.com/video/S21rlwrY74I/v-deo.html
would this work to fix a magnet that got weaker or is it a temporary change?
It should work - but not very well because the field in the device will not be as high as a typical magnets original field, so it wont magnetize the magnet to it max field strength. I did a video on how to remagnetize a magnet here ua-cam.com/video/S21rlwrY74I/v-deo.html in case your interested.
Also with the two different polarities, you must demagnetize with the correct one, otherwise it doesn't work.
I guess if you only had the wrong one, you could remagnetise the other way, and then it would would be able to demagnetise
Because the demagnetizer part is initially forcing the field in the screwdriver to be perpendicular to the length of the screwdriver (the screwdriver is magnetized with the field in a parallel direction), it really shouldn't matter if you use oppositely polarized devices for the magnetize and demagnetize steps. I did wonder if devices from one manufacturer are all polarized one way or the other, or if its completely random with the magnets being manually inserted.
Excellent simple diagram explaining this simple, magical, device 👏 once magnetized, does the screwdriver remain magnetized indefinitely or does it demagnetize over time? If so, how quickly does it demagnetize?
Thanks! Things like screwdrivers tend to loose their magnetism over time, usually as a result of being banged. So it how often you bang them that often determines how long. The steel in them is generally "magnetically soft" meaning they are easy to magnetize because the magnetic domain boundaries can easily move. And that ability of the magnetic domain boundaries to easily move makes it easy for that form of steel to demagnetize as well. Other materials where the domains get locked in place make longer lasting magnets - called magnetically hard materials - which is what permanent magnets are made of.
If its of interest to you, I did a video a while back on how things get magnetized: ua-cam.com/video/S21rlwrY74I/v-deo.html and demagnetized: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
Thanks for the immediate & understandable reply, I'll check out the videos!
If you have iron filings stuck to a magnetized screwdriver, if you smack it really hard against something like a bench vise, it will take all the filings off.
And the shock of a hard blow may also demagnetize the screwdriver!
if you stick your screwdriver in the one with "magnetizer" field in a north orientation then stick it in the one you took apart that was in the south pole orientation, does it demagnetize? Do you have to stick it back into the south pole one a second time to then remagnetize it?
The demagnetizer will work no matter which one you used to demagnetize it - here's why: When the screwdriver is magnetized by either one, the direction of magnetization is parallel to the length of the screwdriver - just the direction is different. When the screwdriver is passed directly over the demagnetizer magnet, the first thing that happens is that the screwdriver is magnetized perpendicular to the the the length of the screwdriver. This wipes out any of the previous magnetization - regardless of direction - that the screwdriver had.
As the screwdriver is pulled out of the demagnetizer it is subjected to a weaker and weaker field that also gradually changes direction to be parallel. Is the change of direction + the weakening field that lowers the amount of magnetization left after a swipe though the demagentizer.
I used to work at a place that demagnetised equipment containing instrumets to measure the Earth's magnetic field. It was actually in Ottawa.
I think they used an AC coil, but I am not sure. The path of the tool was important
Interesting - I'm just outside of Ottawa near Carleton Place. An AC coil is the typical way to demagnetize things. The steps in this $3 device effectively makes a decreasing AC field as you move up the steps, so exactly the same idea. I did a video showing how to demagentize with AC a while back: ua-cam.com/video/mGK8oYdEqyE/v-deo.html
@@ElectromagneticVideosNortel alum?
@@beefchicken No - but various smaller companies in the Kanata area. You? Just subscribed to you channel - you have lots of interesting vintage stuff!
@@ElectromagneticVideos never worked there, I’m just interested in the history of the company. When I was 16 I bought an old Nortel PBX at an auction. Figuring that thing out steered me in a direction that led to my career in telecommunications.
Thanks for the subscription, it’s been a bit quiet lately, young kids have that effect on a UA-cam channel!
@@beefchicken How cool - you know it was Nortel / Northern Telecom that was the pioneer in digital telephone switches, and thats what turned the small Canadian manufacturer in a global suppler (until they went bust after the dot com boom).
Completely understand the time issue - making videos does take a lot of time. Are you in the Ottawa area? There should be lots of lots of people with Nortel know-how and information - probably facebook groups with old employees might be a place to look for if you are in need of information.
Amazing! Had one of these for years on my hobby bench inside and although I figured out how to magnetize by fooling around, I had never been that successful demagnetising. I've never taken the gizmo seriously, so thanks for the explanation!
Glad I was of help! To demagentize well you have to be careful to pull the screwdriver out all the way each step, and then insert it one step up. If its slips down when inserting, repeat at that step and the move up.
5:45 missed opportunity to say "through the magic of buying two of them"
Your the second person who said that :)
@@ElectromagneticVideos Great video btw!
@@InbasagarNadar Thanks!
Great video !!! I always wondered how they actually worked on the inside. I had maybe a very vague guess, but I didn’t think it was that simple. The diagram really illustrated it clearly.
As I started watching the video, I thought: “he should get one of those green nanoparticle sheets that show magnetic fields” but then I saw the probe which is fantastic. I’d never seen one like it and was going to ask where it was from but then saw the link you posted on another comment.
In any case, thank you so much for taking the time to make an original educational video about this ubiquitous little device.
Woe - I had not seen those green magnetic field display sheets - just googled - will definitely have to get one! There used to be viewers to see the field on magnetic tape for editing, probably a similar device.
Glad you found the link to the magnetic probe - here it is again in case anyone else needs it www.indigoinstruments.com/magnets/accessories/magnetic-force-3d-compass-magnaprobe-44702.html
Glad you liked the video. I enjoyed figuring out this neat little device!
I used to do oilfield work and one of our tools used the same principle to locate pipe collars in the casing. A CCL or Casing Collar Locator. The main bit of it was two magnets with the same pole facing each other vertically. Between them a coil of wire. The fields hit each other and go straight out a ways radially around the tool. As the tool moved through the well casing, any metal changes in the field induced a current in the coil. Like the mass change where two pipes are screwed together. That then went to the surface via a cable would register on computer software and as raw kicks on a meter directly attached to the line. This device is attached to every tool we ran down hole.
That's fascinating - what a clever way to detect a discontinuity in the casing.
When I was a student I had a magnetics Prof who designed pigs to go down oil pipes and magnetically look for problems. I wonder if that how the pigs did it too?
@@ElectromagneticVideos not sure on the pigs. Never worked on the pipelines. I always worked on the pads. Did what is called wireline. We ran anything from scientific and diagnostic tools to cutters and explosives. And plugs as well. A lot of the scientific stuff was to correlate our logs with drilling logs. For example, we would do cement bond logs on the casing. An acoustic tool that clicked kinda like sonar. The reflections off the casing would chart out on a plot. Showing the general constitution of the material behind the casing pipe. Generally a layer of concrete and then rock formations. Along with that tool was a gamma ray spectrometer and the CCL. The gama tool just reads the gamma radiation in the ground and can then give pretty detailed plots of the rock formations. Mainly detecting hydrocarbon deposits. But many things affect it. That log, along with CCL are used to verify and correlate out well logs with the drilling logs. Basically make sure our squiggly lines match theirs at any given depth. It gets a fair bit deeper, but this comment is probably too long already.
@@cbremer83 It is amazing how hi-tech oil exploration and production is. Not sure of Schlumberger is still around, but way back in the 80s they would show up at my old university around graduation time and hire anyone who had taken the signal processing, electromagnetics and similar courses. I can sure see why fro what you describe.
Never heard of the gamma tool either - fascinating!
Thanks !!!!!!!!!!!!!!!!
Your welcome!
I was scared to publicized this thing I love these things
They certainly are nifty things to have at very low cost!
You're a wonderful teacher! Thank you!
Thank you so much! Thais what I am aiming for in this channel - to explain things in an understandable way!