I worked for a casting company using aluminum. Our cores for the castings were made of resin coated sand . After the casting had cooled the sand was removed and recycled. The sand and tiny bits of aluminum were ran across a belt with a powerful magnet as the end roller. The aluminum bits would actually leap off the belt over a divider and into a bin .
Inside that end roller is another roller inside studded with strong magnets, whirling FAST in the same direction the outer belt-drive roller is turning. The aluminum is lifted & thrown forward, away from the end of the belt. The sand drops straight down. This is used in recycling centers to separate out aluminum from paper &glass. (Steel is separated out first by another overhead upside-down moving belt at right angles with strong stationary permanent magnets above.)
@@emilyyyylime- It's called magnetic particle inspection and is used for finding cracks or surface imperfections on ferromagnetic materials. Basically, the subject being insoected is magnetized then dusted with magnetic particles that tend to clump up at the surface areas around cracks or other disruptions on the surface.
@@emilyyyylime- Eddy Current NDT. You have a small probe, like a tablet stylus, that has two separate D-shaped coils on the end. One these coils induces an electric field into the material that is tested and the other picks it up. The reading of the reading coil gets zeroed on a known-good piece of metal. When sweeping the probe across crack, the reading changes and signals the user with a spike on a display and a sound
You added a shorted turn to make an electromagnet into a ring-shaped "shaded pole". When energized with AC, It has a feeble attraction for copper and aluminum PLATES in CONTACT with it. (You could remove the copper ring, assemble two concentric coils, and drive them independently. That would use less power, and let you tune the frequency, phase difference, and waveform for maximum attraction.)
Used in AC solenoid valves and in AC relay designs and known as a "shading ring or coil" or "Frager spire or Frager coil" to reduce/eliminate frequency chatter. Cable driven speedometers and tachometers use a permanent magnet rotated by the cable to drive a copper or aluminium drag cup which carries a hairspring and the pointer at the shaft end sitting above a printed dial. Drag cup also has a small amount of nickel iron alloy fitted which shunts some of the magnet's flux but as the cup heats up with the induced current and its electrical resistivity rises, shunts less magnetism so compensating for temperature variations. Modern vehicle instruments use moving coil or moving iron meters.
Leonard R Crow - Attracting Copper, Aluminum & Other Non-Ferrous Metals - Extra - an excellently illustrated book well worth reading for its experiments and theory.
I second the recommendation, that book seems to offer a better (and simpler) explanation of the effect. I don't quite think the rotating field thing is the answer.
Years ago I tool a tour of an incinerator. They made their money by collecting steel and other metals out of garbage. A magnet took out the steel and other magnetic material. They used a very strong different magnet for a flight diversion for the other metals. As a aircraft mechanic, I was baffled how a Canadian aircraft company could crimp an aluminum tube onto a steel plug with no mechanical contact. It pushed the tube into rings in the rod ends.
So, it's still a repulsive force. But because the magnet fields are being twisted around onto themselves, it's repulsing the aluminum into the magnet to give it the appearance of attraction.
That opens up the thought of putting a second electromagnet inside the larger one (instead of the copper ring) and through the proper electronic circuit the phase and frequency feeding that coil could be variable. Adjusting from 90 to 180 degrees phase and from 30 to 120 hertz would make an interesting experiment.
When you said some might figure it out from the ring alone, it snapped for me. The copper ring adds a phase shift to the magnetic field, just like in a shaded pole motor. Very neat. Here I was thinking you’d need 3 concentric solenoids being driven 120 degrees out of phase to create an inwardly moving magnetic field.
Try it with miu metal and you'll end up with a big surprise. You essentially have created a stationary rotor and is a simple way of explaining it. The current generated in the piece of metal held up against the oscillating magnet allows it to be held in place. Two things I'd like to try is super cool the metals held up against the magnet and change the frequency on the magnet input
To be fair, we can already sort of do that using Lez's law. Another comment and reply talks about an eddy current separator that just separates out aluminum and other non-ferrous metals. However, there's nothing stopping a more precise version acting like air separators do.
To be fair, we can already sort of do that using Lez's law. Another comment and reply talks about an eddy current separator that just separates out aluminum and other non-ferrous metals. However, there's nothing stopping a more precise version acting like air separators do.
The idea is simple. Thinking, being competent and successful in implementing it is complex. Almost everyone thought of flying like birds, very few invented machines capable of flying.
For fun, pull the gold to the sides of full Goldschlager booze. Talk about a cool bartender trick. Also this could be a "catch all" for my sluices. Pull the black sand out with one magnet, use another to raise the flour gold from the silt. Lose NONE of the super fine gold.
It took me a minute after seeing the copper ring, then I realized you took Lenz law and hit it with that uno reverse card. You had your magnet push the aluminum toward you because it couldn't pull it.
@lowiq888 Tell me, where are the output leads of the transformer? In electrical circuits, transformers via the ratio of turns in their primary (input) and secondary (output) coils either step voltage up, thus reducing current; step voltage down, increasing current; or they keep voltage the same, providing electrical isolation. Transformers do not convert electrical energy into mechanical energy; electromagnets, solenoids, and motors do that.
It is not a magnet, and it pushed the aluminum because of mutual inductance. Are you illiterate like Elon Musk. He uses the word "compute" as a noun. Barack Obama thinks technology is an adjective. Magnets do not attract copper yet some transformers do.
did you watch the video? Transformers don't really have output leads. You can turn a transformer around and use the output for an input and so they are called primaries and secondaries. Transformers do convert electrical energy into magnetic fields and back to electricity and can provide isolation. Some Auto-transformers do not provide isolation. The device is an autotransformer. (it has a single core.) Transformers are devices that use MUTUAL INDUCTANCE. That is what this device does. The copper ring is the secondary. I if I could examine the device and play with it, we can confirm or deny all that. Additionally, the paramagnetic material that is attracted by the device is probably charged due to mutual induction. That is why it sticks. All the evidence points toward the device being a transformer. You would have to contradict the dictionary and many other books to call it a magnet. Magnets simply do not attract AL and CU. I have also seen so called AC solenoids. These are considered to be solenoids, not magnets. The transformer is atypical, but that don't make it a magnet. DC motors often have magnets in them. Does that make a motor a magnet? No. Does that make a doorknob a magnet? The earth is a magnet. How can you deny that the copper ring is being charged by mutual induction? The copper ring is also similar to a device called a CURRENT TRANSFORMER. Lastly I would say that if you can turn it on, and make a spark with it, then it is a transformer. Magnets do not make sparks and arcs. You can probably connect the output leads to opposite sides of the copper ring, or from the core and the copper ring. Try to connect 2 wires, one from the attracted sheet of copper, and one to the core.
I thought the size of the metal pieces would be important. I suspected the repulsion would be only at the edges of the cylinder but I'm still surprised it works. Thanks for making the contraption and explaining it. I found it very interesting.
The magnetic field is folding back into itself so it is still repelling the AL, but its repelling it TOWARD itself. The cool thing would be to embed a more powerful coil in the end of the steel core.
The magnetic field through the copper ring, produces a current and the steel "core" inside the ring produces another magnetic of the opposite pole. The same happens in the non ferrous metals. Although they are not magnetic, they DO produce a current when exposed to this magnetic turmoil and creates its own current AND magnetic field, and so they attract. So its not the copper or aluminium that is attracted, but the magnetic field of the metal that is attracted. I imagine that if you use the right size of copper ring and piece of non ferrpus metal, you could also repel.
@@aeroearththat is for sure a lesson that can be learned from those institutions. My experience was that particular lesson was frowned upon and not intentionally taught.
As another check on understanding, might be nice to build a different sized magnet and make sure the effect behaves consistently. I'm assuming it would, but be interesting to see how it scales. E.g. larger diameter and different lengths.
This principal has been used for over a century in many applications. This is how an induction disc relay operates. The disc itself is aluminum, but yet it rotates when current is applied to an induction coil with a shaded pole. This creates the torque necessary to rotate the disc. Also, the current is also passing through the disc itself, so the magnetic field created there interacts with a stationary permanent magnet that is used for dampening and speed of the disc.
I've always had the idea of making a brass magnet for use at the range, it goes something like a push reel mower but with magnets instead of blades and a catch bag.
Nifty AF ! I was well aware that you could get skip/drag-like interaction via "physical" rotation but its more or less just akin to ordinary braking. I can't say I ever seen exactly this though. 👍
Excellent video. I investigated the aluminum ring physics in which an aluminum ring will rise on a vertical iron electromagnet driven by AC. I concluded the ring can be considered a dead short secondary to the primary coil. It follows Faraday's law, but the shorted single-turn secondary idea made it simpler to understand. The shorted secondary experiences a large circumferential eddy current that opposes the electromagnet field because its phase is 90 degrees off. In your case, the shorted secondary is embedded. Again, fascinating video.
If this is Your idea I would get it patented!! I had an eye injury in the 00's caused by recklessness with my Dremel, grinding the burrs off some Alum . I was asked the usual Eye Injury questions but because the fragment in my eye was Non Ferrous, they couldn't use the High Powered EM they had, for removing Ferrous objects from the eye(!) so they had to use the Scraping action of the blade of a scalpel to dislodge it!!
the " Loop " simply pushes against the " material " in it's path , hence the reason the larger piece doesn't move toward the coil , it blocks the path .
Seems like the same principle as when you drop a large magnet onto a chunk of aluminum, itll slow itself. I think that also works if you pull it away quickly, so all you need is some kind of arrangement that has a moving magnetic field, and the part you wish to attract inside the part of the field moving in the correct direction.
Another way of thinking about it is that right against the face of the bar is a more efficient place for the plate than out in the complicated field. i.e. Less heating. You might get some interesting insights by trying a ring or a star shape to control where (or how large) the eddy currents can be, and try thicker and thinner plates. An interesting phenomena which might be related, is that inductive proximity sensors (which are good at detecting ferrous targets) are only about 10% as sensitive (compared to iron) to aluminum targets, but 90% as sensitive to aluminum FOIL.
It's also worth taking eddy currents into effect, for instance how if you drop a strong magnet through an aluminium or copper pipe the eddy currents drastically slow down the magnet. Cool the magnet with liquid nitrogen & you get close to 3.5x stronger eddy current. Also, said currents always follow the right hand rule, so they introduce the current into the pipe horizontally, & usually a good centimeter or better in front of the actual magnet. The same thing happens in a car alternator because of the use of a "crab cage" rotor. Because it's "legs" are bent @ 90 degrees it redirects the magnetic field almost completely, via a 90 degree shift, even though the magnets themselves field lines are in the opposite orientation.
Great job except that it is not a magnet, it is a transformer, and 202 commentors seem to thing it is a magnet. Modern humans are clearly stupid, and it gets worse when they watch TV.
I made a large electromagnet years ago. I drilled a hole in the top of the steel core and put a dal rod in the hole and put an aluminum disk with a in the center on the dal rod. When I ran the electromagnet on AC the aluminum disk would lift in to the air vibrate and hum. After about a minute it would get very hot. When I tried it on DC the aluminum disk jumped straight up hit the ceiling and fell to the floor. I was told that aluminum repells 2% of the magnetic energy it receives and gold repells 1%.
Does it work better if you put saw-cuts across the iron parts of the face? The original 1950s project use wads of nails as laminations. Perhaps even an "X" cut in the steel core, would block eddy currents and improve things (a lot? or a little?)
Would it work for a copper sheet the same size as the aluminum? It seems like copper's higher conductivity would decrease the size of the magnetic field. It looks like it is a balance between the induced current and the size of the plate. Too small of an induced current and it doesn't interact with the source field. Too large of a current and the source field gets too small.
A very good explanation of magnetic properties, thanks sir, I have a question what would happen if you insulated the copper windings on that electro magnet with a copper and or aluminum ring how would that affect the reaction? Would it increase or decrease its magnetic state?
Can you use this effect for pulsing the field on and off that acts like a pezo electric crystal. Tesla mentioned using frequency in dealing with electrical currents
i remember looking up how recyclers sort metals from ferrous...i found out they have a second coil/field...when the aluminum/copper are in the field they can be moved by the electromagnet. but mainly they use a winnowing proess whereby air pressure is used to blow off light things like aluminum cans are blown off and heavy things continue on down.
Lovely explanation, I wonder how different ratios of area and volume of the Sub-Sokenoid yo the Electromagbet would change the effective size of copper we can attract.
I don't know, but the device is not a magnet, or an electromagnet. The device is an autotransformer. Electromagnets use DC current, not AC. Almost 200 commenters got that wrong.
So if you had more windings in the core would the magnetic pull be stronger? Or how about multiple rings seperated by steele? Is ther a way for high grade stainless to be attracted?
One interesting thing to evaluate is the current in the copper ring. I have feeling that the current must be surprisingly large because a single turn secondary is creating a strong enough field to sense repulsion. Odd having very large current in ultra low resistance short that doesn't generate much heat. Seems odd to me, anyway.
Reversing the direction of the magnetic field surely has a profound effect much like if the direction of the earths magnetic north and South poles switched, not turned on and off.
You can magnatise any material insulator or not. Thats how electronic air cleaners operate. Makining opposites attract. Similat to rubbing a balloon on your hait and putting it on the wall.
Does the larger prices of metal not work because on the edges it starts to make a larger outward facing field? Also what would happen if you had the copper annular inserts in series? Or is it generally better to just have one main ring?
Do you know what would happen if the coil wasn't around the steel, but if it was an aircoil and would be inserted into a steel tube? Would such electromagnet attract diamagnetic materials as well?
That has got to be the most well explained video. The question I'm asking myself is would that happen because negatively charged ion are interacting with positive ions to create the field also?
WOW! and the Al and Cu are still repelled by an alternating current, it's just that the "face" of the AC magnet is essentially "virtual" (for lack of a better word). I knew I had seen the math before, but only as it applied to negative effects in Switched Reluctance Motors. Depending on frequency and motor design, the ferromagnetic attraction between the Teeth on the Rotor and the Teeth on the Stater will be reduced thus lowering the Motor's efficiency.
I knew it was possible after inducing a field in the brass/copper/aluminium to have a field out of phase affect it and use that induced field to attract it, but had no idea how to go about it.
Nice explanation . What else would be good to know is what exactly is reacting to the toroid field in the aluminum and copper . Both are known to be highly active in the presence of a magnetic field. Thanks for the share. :O
"Make a magnetic device that repels a piece of copper onto it." If the lecturer had said that it would have been an honest request. Instead you were lied to, it helps prevent success.
So the electron magnet has to be AC power source correct? I have a CNC Milling machine so I'm going to make one, but I didn't know if I needed to use AC or DC power. I assumed AC, but if it can be done with DC then I could make a more portable one.
This effect was used many years ago in record player motors, where a disc of aluminium was run in between two poles of a horseshoe AC magnet, which caused a rotation of the disc.
That is called a homopolar motor. The old electric meters worked the same way,. The rate of spin is determined by the amount of current not voltage passing through the coil, that's the key.
A ferrite core would be iron dust mixed in a ceramic can also work, but what if you now suspend copper or aluminium filings instead of iron and see if that does not work better?
Years ago I reed about a man who made a different kind of electromagnet in the 1950's that would ball up the electrical field in stead of the magnetic field. The electrical field would pull nonmagnetic metals to it. His electromagnet was shaped like a donut instead of a rod.
I worked for a casting company using aluminum. Our cores for the castings were made of resin coated sand . After the casting had cooled the sand was removed and recycled. The sand and tiny bits of aluminum were ran across a belt with a powerful magnet as the end roller. The aluminum bits would actually leap off the belt over a divider and into a bin .
*run
@@nonyadamnbusiness9887 Sounds like an eddy current separator, a standard piece of industrial equipment.
Eddy currents would drag those types of metals off a conveyor feed.
Inside that end roller is another roller inside studded with strong magnets, whirling FAST in the same direction the outer belt-drive roller is turning. The aluminum is lifted & thrown forward, away from the end of the belt. The sand drops straight down. This is used in recycling centers to separate out aluminum from paper &glass. (Steel is separated out first by another overhead upside-down moving belt at right angles with strong stationary permanent magnets above.)
If only such a magnet can attract salt out of water, can always dream.
Fun fact, you can replace the copper ring with a coil, scale it down to 3.5 mm or so and use it inspect nonferrous materials for cracks.
This sounds interesting but I have absolutely no idea what you're referring to. Mind elaborating?
@@emilyyyylime- Eddy current nondestructive testing.
@@emilyyyylime-
It's called magnetic particle inspection and is used for finding cracks or surface imperfections on ferromagnetic materials. Basically, the subject being insoected is magnetized then dusted with magnetic particles that tend to clump up at the surface areas around cracks or other disruptions on the surface.
@@emilyyyylime- Eddy Current NDT. You have a small probe, like a tablet stylus, that has two separate D-shaped coils on the end. One these coils induces an electric field into the material that is tested and the other picks it up. The reading of the reading coil gets zeroed on a known-good piece of metal. When sweeping the probe across crack, the reading changes and signals the user with a spike on a display and a sound
Fun fact, experiment is king?
You added a shorted turn to make an electromagnet into a ring-shaped "shaded pole". When energized with AC, It has a feeble attraction for copper and aluminum PLATES in CONTACT with it. (You could remove the copper ring, assemble two concentric coils, and drive them independently. That would use less power, and let you tune the frequency, phase difference, and waveform for maximum attraction.)
I remember eddy current "magnet" to pickup copper and aluminum in Popular Electronic magazine of the 1980s.
Used in AC solenoid valves and in AC relay designs and known as a "shading ring or coil" or "Frager spire or Frager coil" to reduce/eliminate frequency chatter.
Cable driven speedometers and tachometers use a permanent magnet rotated by the cable to drive a copper or aluminium drag cup which carries a hairspring and the pointer at the shaft end sitting above a printed dial. Drag cup also has a small amount of nickel iron alloy fitted which shunts some of the magnet's flux but as the cup heats up with the induced current and its electrical resistivity rises, shunts less magnetism so compensating for temperature variations. Modern vehicle instruments use moving coil or moving iron meters.
Yes but the device in question is not a magnet. The device is an autotransformer. Electromagnets use DC current.-
Leonard R Crow - Attracting Copper, Aluminum & Other Non-Ferrous Metals - Extra
- an excellently illustrated book well worth reading for its experiments and theory.
I second the recommendation, that book seems to offer a better (and simpler) explanation of the effect. I don't quite think the rotating field thing is the answer.
Cool, I knew about dropping a magnet through a copper tube, but never imagined the property could be used like that.
Years ago I tool a tour of an incinerator. They made their money by collecting steel and other metals out of garbage. A magnet took out the steel and other magnetic material. They used a very strong different magnet for a flight diversion for the other metals.
As a aircraft mechanic, I was baffled how a Canadian aircraft company could crimp an aluminum tube onto a steel plug with no mechanical contact. It pushed the tube into rings in the rod ends.
Z-pinch?
Only company I'm aware of who makes such tools is Maxwell Magneform. The crimping is done with magnetic repulsion due to eddy currents in aluminum.
OMG Thank you!!! I watched that lecture and it blew my mind (classic Gelbart) but also drove me crazy that he didn't discuss it further.
So, it's still a repulsive force. But because the magnet fields are being twisted around onto themselves, it's repulsing the aluminum into the magnet to give it the appearance of attraction.
Well put.
there's nothing behind it how could it be repulsed?
I don't know either btw, jus saying this is weird
I always found magnetism mysterious, the fact that it acts like gravity but it made of electric
@@IndieGuvenc The field itself has been warped so that it pushes from behind in a way...I think. Lol
That opens up the thought of putting a second electromagnet inside the larger one (instead of the copper ring) and through the proper electronic circuit the phase and frequency feeding that coil could be variable. Adjusting from 90 to 180 degrees phase and from 30 to 120 hertz would make an interesting experiment.
very interesting although the device is not a magnet. The device is an auto-transformer. Electromagnets use DC current.
Sheldon explains physics to Penny....or words to that effect
When you said some might figure it out from the ring alone, it snapped for me. The copper ring adds a phase shift to the magnetic field, just like in a shaded pole motor. Very neat. Here I was thinking you’d need 3 concentric solenoids being driven 120 degrees out of phase to create an inwardly moving magnetic field.
You should veiw it through a ferroscope or put ferro fluid on it and see how it behaves
ferro fluid? - perhaps warm copper grease
I was hoping he was going to show those magnetic lines interaction
Try it with miu metal and you'll end up with a big surprise.
You essentially have created a stationary rotor and is a simple way of explaining it. The current generated in the piece of metal held up against the oscillating magnet allows it to be held in place.
Two things I'd like to try is super cool the metals held up against the magnet and change the frequency on the magnet input
HOLY SHIT ! Youre able to seperate non-magnetic metals by size with this !!!!!!
To be fair, we can already sort of do that using Lez's law. Another comment and reply talks about an eddy current separator that just separates out aluminum and other non-ferrous metals. However, there's nothing stopping a more precise version acting like air separators do.
To be fair, we can already sort of do that using Lez's law. Another comment and reply talks about an eddy current separator that just separates out aluminum and other non-ferrous metals. However, there's nothing stopping a more precise version acting like air separators do.
please define "non-magnetic" metal
@@havocking9224he means not like the normally magnetic metals like iron or steel
@@readyeddie2065is good, he fixed his comments :D
Awesome! I want to try filtering out gold with this now
I'm sure no one thought of that before
Was thinking the same thing .
The idea is simple. Thinking, being competent and successful in implementing it is complex. Almost everyone thought of flying like birds, very few invented machines capable of flying.
For fun, pull the gold to the sides of full Goldschlager booze. Talk about a cool bartender trick. Also this could be a "catch all" for my sluices. Pull the black sand out with one magnet, use another to raise the flour gold from the silt. Lose NONE of the super fine gold.
Good explanation, Cylo. Thanks for sharing it.
It took me a minute after seeing the copper ring, then I realized you took Lenz law and hit it with that uno reverse card. You had your magnet push the aluminum toward you because it couldn't pull it.
The device is not a magnet. the device is a transformer.
@lowiq888 Tell me, where are the output leads of the transformer? In electrical circuits, transformers via the ratio of turns in their primary (input) and secondary (output) coils either step voltage up, thus reducing current; step voltage down, increasing current; or they keep voltage the same, providing electrical isolation.
Transformers do not convert electrical energy into mechanical energy; electromagnets, solenoids, and motors do that.
@lowiq888 I should have put magnet in quotes.
It is not a magnet, and it pushed the aluminum because of mutual inductance. Are you illiterate like Elon Musk. He uses the word "compute" as a noun. Barack Obama thinks technology is an adjective. Magnets do not attract copper yet some transformers do.
did you watch the video? Transformers don't really have output leads. You can turn a transformer around and use the output for an input and so they are called primaries and secondaries. Transformers do convert electrical energy into magnetic fields and back to electricity and can provide isolation. Some Auto-transformers do not provide isolation. The device is an autotransformer. (it has a single core.) Transformers are devices that use MUTUAL INDUCTANCE. That is what this device does. The copper ring is the secondary. I if I could examine the device and play with it, we can confirm or deny all that. Additionally, the paramagnetic material that is attracted by the device is probably charged due to mutual induction. That is why it sticks. All the evidence points toward the device being a transformer. You would have to contradict the dictionary and many other books to call it a magnet. Magnets simply do not attract AL and CU. I have also seen so called AC solenoids. These are considered to be solenoids, not magnets.
The transformer is atypical, but that don't make it a magnet. DC motors often have magnets in them. Does that make a motor a magnet? No. Does that make a doorknob a magnet? The earth is a magnet. How can you deny that the copper ring is being charged by mutual induction?
The copper ring is also similar to a device called a CURRENT TRANSFORMER. Lastly I would say that if you can turn it on, and make a spark with it, then it is a transformer. Magnets do not make sparks and arcs. You can probably connect the output leads to opposite sides of the copper ring, or from the core and the copper ring. Try to connect 2 wires, one from the attracted sheet of copper, and one to the core.
I thought the size of the metal pieces would be important. I suspected the repulsion would be only at the edges of the cylinder but I'm still surprised it works. Thanks for making the contraption and explaining it. I found it very interesting.
The magnetic field is folding back into itself so it is still repelling the AL, but its repelling it TOWARD itself.
The cool thing would be to embed a more powerful coil in the end of the steel core.
The magnetic field through the copper ring, produces a current and the steel "core" inside the ring produces another magnetic of the opposite pole.
The same happens in the non ferrous metals. Although they are not magnetic, they DO produce a current when exposed to this magnetic turmoil and creates its own current AND magnetic field, and so they attract. So its not the copper or aluminium that is attracted, but the magnetic field of the metal that is attracted.
I imagine that if you use the right size of copper ring and piece of non ferrpus metal, you could also repel.
Smart professor. Using the Zeigarnik effect to make students go and learn more about the lecture and even duplicate the experiments.
The most important lesson I learnt at school and college was to go find out for myself.
@@aeroearththat is for sure a lesson that can be learned from those institutions. My experience was that particular lesson was frowned upon and not intentionally taught.
@@MadHeadzOzby some lecturers yeah. It's indirectly saying that their teaching isn't good enough
You had me completely befuddled. That is slicker than snot!!
07:05 *Subsolenoid*.. I love that😂
I have no idea what you said but as soon as I saw the copper ring I knew exactly what was happening. Thanks for the video.
Like a shaded electromagnet
As another check on understanding, might be nice to build a different sized magnet and make sure the effect behaves consistently. I'm assuming it would, but be interesting to see how it scales. E.g. larger diameter and different lengths.
Longer Cylinder in Center may Strengthen Inner Rotating Toroidal Field lines ?
This principal has been used for over a century in many applications. This is how an induction disc relay operates. The disc itself is aluminum, but yet it rotates when current is applied to an induction coil with a shaded pole. This creates the torque necessary to rotate the disc. Also, the current is also passing through the disc itself, so the magnetic field created there interacts with a stationary permanent magnet that is used for dampening and speed of the disc.
I've always had the idea of making a brass magnet for use at the range, it goes something like a push reel mower but with magnets instead of blades and a catch bag.
It's akin to dropping a magnet down a copper pipe! Eddy currents opposing the downward fall.
This same principle is used in old watt meters to create a torque on the disk
Nifty AF ! I was well aware that you could get skip/drag-like interaction via "physical" rotation but its more or less just akin to ordinary braking. I can't say I ever seen exactly this though. 👍
When you're defying the laws of physics, you've got to be sneaky.
Thank you for sharing this was very informative. You made it easy to follow you. Thanks again
Found very interesting, enjoyed the video.
you should get some of that plastic sheet stuff that allows you to see magnetic fields and hold it above your copper ring electro-magnet
It's called magnetic film.
Thanks for showing the magic trick. Indeed once you show the copper ring (an the previous mention of Lenz’s law) it all makes sense.
I think we can look at this another way as well: we're not attracting the nonferrous metals, we're trapping them by inducing current.
It's all just magic! That was interesting. Thanks for sharing 😊
Excellent video. I investigated the aluminum ring physics in which an aluminum ring will rise on a vertical iron electromagnet driven by AC. I concluded the ring can be considered a dead short secondary to the primary coil. It follows Faraday's law, but the shorted single-turn secondary idea made it simpler to understand. The shorted secondary experiences a large circumferential eddy current that opposes the electromagnet field because its phase is 90 degrees off. In your case, the shorted secondary is embedded. Again, fascinating video.
If this is Your idea I would get it patented!!
I had an eye injury in the 00's caused by recklessness with my Dremel, grinding the burrs off some Alum .
I was asked the usual Eye Injury questions but because the fragment in my eye was Non Ferrous, they couldn't use the High Powered EM they had, for removing Ferrous objects from the eye(!) so they had to use the Scraping action of the blade of a scalpel to dislodge it!!
Thanks for sharing this! Very cool.
Interesting & absolutely clever. Inversely, wonder how that would effect power generated.
the " Loop " simply pushes against the " material " in it's path , hence the reason the larger piece doesn't move toward the coil , it blocks the path .
great job! I understood your explanation. Makes sense.
Dave Lambright has videos where he has made aluminum magnetic and other crazy stuff
Thank you.Very clear. Got me thinking about applications
Well explained sir. I assumed the title was clickbait and this was a scam. I understood enough of the physics to believe it is not.
It’s interesting you mentioned Dan Gelbart. With many of your videos, I tend to think that you must be his successor. 😊
Seems like the same principle as when you drop a large magnet onto a chunk of aluminum, itll slow itself. I think that also works if you pull it away quickly, so all you need is some kind of arrangement that has a moving magnetic field, and the part you wish to attract inside the part of the field moving in the correct direction.
Another way of thinking about it is that right against the face of the bar is a more efficient place for the plate than out in the complicated field. i.e. Less heating. You might get some interesting insights by trying a ring or a star shape to control where (or how large) the eddy currents can be, and try thicker and thinner plates.
An interesting phenomena which might be related, is that inductive proximity sensors (which are good at detecting ferrous targets) are only about 10% as sensitive (compared to iron) to aluminum targets, but 90% as sensitive to aluminum FOIL.
It's also worth taking eddy currents into effect, for instance how if you drop a strong magnet through an aluminium or copper pipe the eddy currents drastically slow down the magnet. Cool the magnet with liquid nitrogen & you get close to 3.5x stronger eddy current. Also, said currents always follow the right hand rule, so they introduce the current into the pipe horizontally, & usually a good centimeter or better in front of the actual magnet. The same thing happens in a car alternator because of the use of a "crab cage" rotor. Because it's "legs" are bent @ 90 degrees it redirects the magnetic field almost completely, via a 90 degree shift, even though the magnets themselves field lines are in the opposite orientation.
Great job at explaining this.
Great job except that it is not a magnet, it is a transformer, and 202 commentors seem to thing it is a magnet. Modern humans are clearly stupid, and it gets worse when they watch TV.
I made a large electromagnet years ago. I drilled a hole in the top of the steel core and put a dal rod in the hole and put an aluminum disk with a in the center on the dal rod. When I ran the electromagnet on AC the aluminum disk would lift in to the air vibrate and hum. After about a minute it would get very hot. When I tried it on DC the aluminum disk jumped straight up hit the ceiling and fell to the floor. I was told that aluminum repells 2% of the magnetic energy it receives and gold repells 1%.
Thanks. A brand new area of physics I'd never heard of.
Very interesting.
Could this principle be used in further magnetic levitation research?
Does it work better if you put saw-cuts across the iron parts of the face? The original 1950s project use wads of nails as laminations. Perhaps even an "X" cut in the steel core, would block eddy currents and improve things (a lot? or a little?)
That is why elcectricity is thunder
great explanation. I totally understand the attraction of opposing fields of flux...
Would it work for a copper sheet the same size as the aluminum? It seems like copper's higher conductivity would decrease the size of the magnetic field.
It looks like it is a balance between the induced current and the size of the plate. Too small of an induced current and it doesn't interact with the source field. Too large of a current and the source field gets too small.
A very good explanation of magnetic properties, thanks sir, I have a question what would happen if you insulated the copper windings on that electro magnet with a copper and or aluminum ring how would that affect the reaction? Would it increase or decrease its magnetic state?
Can you use this effect for pulsing the field on and off that acts like a pezo electric crystal. Tesla mentioned using frequency in dealing with electrical currents
i remember looking up how recyclers sort metals from ferrous...i found out they have a second coil/field...when the aluminum/copper are in the field they can be moved by the electromagnet. but mainly they use a winnowing proess whereby air pressure is used to blow off light things like aluminum cans are blown off and heavy things continue on down.
Great Work Thanks
Have you played with different frequency's?
This is amazing. Thank you xx
Lovely explanation, I wonder how different ratios of area and volume of the Sub-Sokenoid yo the Electromagbet would change the effective size of copper we can attract.
I don't know, but the device is not a magnet, or an electromagnet. The device is an autotransformer. Electromagnets use DC current, not AC. Almost 200 commenters got that wrong.
So if you had more windings in the core would the magnetic pull be stronger? Or how about multiple rings seperated by steele? Is ther a way for high grade stainless to be attracted?
Perhaps having the copper toroid protruding from the surface of the steel bar would enhance the effect.
Thank you your video was interesting and good to have this knowledge..
Thank you very much and your video is very interesting as well.We can expand on these subjects
eddies to attract eddies
One interesting thing to evaluate is the current in the copper ring. I have feeling that the current must be surprisingly large because a single turn secondary is creating a strong enough field to sense repulsion. Odd having very large current in ultra low resistance short that doesn't generate much heat. Seems odd to me, anyway.
Reversing the direction of the magnetic field surely has a profound effect much like if the direction of the earths magnetic north and South poles switched, not turned on and off.
"Apprentice, go get the aluminum magnet"...
Sure, there it is
You can magnatise any material insulator or not. Thats how electronic air cleaners operate. Makining opposites attract. Similat to rubbing a balloon on your hait and putting it on the wall.
Does the larger prices of metal not work because on the edges it starts to make a larger outward facing field? Also what would happen if you had the copper annular inserts in series? Or is it generally better to just have one main ring?
Do you know what would happen if the coil wasn't around the steel, but if it was an aircoil and would be inserted into a steel tube? Would such electromagnet attract diamagnetic materials as well?
You can induce currents into both aluminum and copper, making them electro magnets. This is how electric motors work.
That has got to be the most well explained video.
The question I'm asking myself is would that happen because negatively charged ion are interacting with positive ions to create the field also?
WOW! and the Al and Cu are still repelled by an alternating current, it's just that the "face" of the AC magnet is essentially "virtual" (for lack of a better word). I knew I had seen the math before, but only as it applied to negative effects in Switched Reluctance Motors. Depending on frequency and motor design, the ferromagnetic attraction between the Teeth on the Rotor and the Teeth on the Stater will be reduced thus lowering the Motor's efficiency.
I knew it was possible after inducing a field in the brass/copper/aluminium to have a field out of phase affect it and use that induced field to attract it, but had no idea how to go about it.
I found that video at - 2021 Nov.25 - Dan Gelbart by UBC Engineering Physics Project Lab
Nice explanation . What else would be good to know is what exactly is reacting to the toroid field in the aluminum and copper . Both are known to be highly active in the presence of a magnetic field. Thanks for the share. :O
Can this method then be used to improve EMI by forcing the electrons to move towards ground much faster?
"Make a magnetic device that repels a piece of copper onto it."
If the lecturer had said that it would have been an honest request.
Instead you were lied to, it helps prevent success.
So the electron magnet has to be AC power source correct? I have a CNC Milling machine so I'm going to make one, but I didn't know if I needed to use AC or DC power. I assumed AC, but if it can be done with DC then I could make a more portable one.
Interesting. Thanks.
The workpiece becomes a rotor in an open shaded-pole induction motor
I wonder if making a core with two concentric copper rings would increase or decrease the attraction force...
This effect was used many years ago in record player motors, where a disc of aluminium was run in between two poles of a horseshoe AC magnet, which caused a rotation of the disc.
That is called a homopolar motor. The old electric meters worked the same way,.
The rate of spin is determined by the amount of current not voltage passing through the coil, that's the key.
That's also the same principle that causes Galaxy rotation.
?
super cool, thanks!
If you had a whole in the center of your metal shaft and copper ring, and you put it in the water, would that make a pump?
Are the effects the same if you put an aluminum ring in the other end of the steel rod?
can you use iron filings to show what is happening with the currents?
A ferrite core would be iron dust mixed in a ceramic can also work, but what if you now suspend copper or aluminium filings instead of iron and see if that does not work better?
EXCELLENT SIR!
Constant DC can do that , so can certain other pulsed frequencies
thanks! so does it work with carbon as well?
What does your magnet do when you put it on the copper ring end?
Years ago I reed about a man who made a different kind of electromagnet in the 1950's that would ball up the electrical field in stead of the magnetic field. The electrical field would pull nonmagnetic metals to it. His electromagnet was shaped like a donut instead of a rod.