I need help for a mini-project under a prof. My topic is magnetic levitation and i need the procedure of the experiment. pls help
Topic by shounakghosh18 | last reply
http://youtu.be/zqG-TL0WnjE How does this device work? Has it ever been on instructables or anything like it? How would I go about mounting the magnets on the rotor? What sort of spring would I need for the magnet mounted to the vertical shaft that slides up and down? In short I want to know every little detail about building it before I begin so I don't go buying a lot of unecessary stuff and waste money.
Topic by merlin280 | last reply
So... before I start... I am not a physicist, nor am I an electrical engineer. Hopefully someone within one of those (or both) professions will chime in and enrich this discussion. That said... I'm going to be using leyman's terms. This thread is specifically meant to explain how a brushless DC electric motor exerts a force, and how that force is used to generate work. To start off, I'd Like to explain the components which comprise a brushless DC motor: First... You have an axil. The axil's purpose is to spin. Next you have natural magnets, or solid state magnet; I use the terms somewhat incorrectly, since a natural magnet refers specifically to nickel or ferrous base magnets, but there exist a large variety of compounds and composites that exhibit the ability to produce magnetic fields. In practice you have many in a motor, but for our purposes... we can pretend we have one. The natural magnet's job is exert a magnetic field while attached to the axil. After that we have an electrical coil. Once again, in Brushless DC motors, we have many of these, but for our purposes we'll use 3. The electrical coil's job is to produce a magnetic field which can move in a circle. Finally we have the engine housing. The purpose of the engine housing is to hold everything together. Note: I'm intentionally leaving out the computer control mechanism. there are alot of great instructables on microcontrollers. Most Brushless DC motors requrie one to work since there is no mechanical timing device, as there is in a brushed engine. So... how does this fit together? In this setup the natural magnet produces a force when next to the electrical coil (This coil is also known as an electromagnet). This is because the charge of the coil is opposite to the charge of the natural magnet. Once the Natural magnet and the electromagnetic coil align with each other, the first coil shuts off and the second turns on. Once again the natural magnet is drawn towards the magnetic pole. This process repeats until the natural magnet has spun in a circle (note: usually you want it to continue to spin beyond a single revolution.) That's the basic (very basic) idea behind a Brushless DC Motor.
Topic by Qcks | last reply
Some people just love to play with magnets and have a lot of them.If you are just like that and like to tinker a bit then I might have something for you.What magnets you use for the following experiment does not really matter but you should have 20 or 30 of identical properties.Can be disk magnets, block magnets or cubes, just not spheres ;)If you have a 3D printer you use it to make it fancy but a peice of wood, acrylic or such and a drill will do for round magnets.For cubes or flat packs you can make retaining walls on a flat surface.The experiment goes like this:I assume you already tried ways to combine your magnets to make them stronger, like stacking them up.But there is another way to really increase how strong they are combined.Start with one magnet at the center.Then like a ring add more magnets around it but with the oppisite side up.The created mounting solution is to prevent them flipping up and together, you want them as close as possible though.Add another ring and change the direction of the field again.Try this magnet, once all magnets are secured and compare the holding strenght to any other combo you tried so far.It will be much higher for the same amount of magnets.If you want to prevent the use of glue then try to create your mounting system with a really flat but strong enough bottom - this will then be the contact surface.Slightly reduced strength but you can re-use magnet with ease.But if you want to get a really strong one you need cube magnets.Like before you want to create some sort of grid, this time we go for a square.Start with cube in the center, facing north up.Leave enough space in your construction to add 8 more cubes around it - like on the face of a rubik's cube.Leave them empty for now !Add nother row, this time 16 to keep the square.Of course these one go with the south side facing up!Again one empty of 48 and then one last one with north side up with 196 magnets.Ok, to be fair, you wouldn't be able to pull it off a metal surface unless you used really tiny cubes, so if in doubt then go for just to 48 and leave the enter one out for now.Should be quite intense but similar to what any other shaped magnet would have done.Time to fill the voids!Add the cubes in the spce between the magnets so the north and south side face the magnets next to it!So basically sideways but in the correct orientation.You can then also add the center piece - try either orientation for that one ;)What happened now is that you forced the magnetic field lines to go up instead od for trying to go the easiest and shortest way to the next magnet.And "up" is where our magnetic surface would be, which provides the now overdue shortcut for the magnetic fields.Be amased how much stronger this version is and how much even 3x3x3 cubes would accomplish.With 10x10x10mm N52 magnets you might be able to use them support our wieght if you pull straight dwon from a horizontal surface...Ok, kidding, not just might, unless you are really big...One 10x10x10 might hold about 6kg.Stacked up a bit more but having 20 or stcked up would not be much stronger than 10.Even just 25 magnets with one in the center, one row of sideways orientated and one row with opposing field to the center one would be hard to remove from a steel surface.If we go with the imagined 6kg per magnet we could assume to get 25 x 6 = 150kg of holding power.Check you single magnet first then compare to the square of 25 ;)Consider using some plastic between magnet and surface so you can at least slide or pry it off if you have to.You can also combine magnets or a new one that has one side appear much stronger than the other.Meaning that for example on the north side it could hold 20kg while on the south side only 5.
Topic by Downunder35m
I am working on a project in which I have to control a small setup at the end of a motor shaft using an electromagnet. The electromagnet needs to be around the shaft inbetween the setup and the motor. So I have used a metallic ferromagnetic spool(image attached) and wound 32 gauge wire on it to make it an electromagnet and put the shaft through it. Since this core made out of spool is hollow, I'm not sure how the magnetic field will behave. I tried powering up the one I made and it' seems to be both attracting and repelling a magnet's pole (edges attract while centre somewhat repels). Anyone got any idea about this?
Topic by Antzy Carmasaic | last reply
People, I need your help! I'm a student at college and my primer subject is physics. Let's just say I know enough about electricity and power. But my major obstacle towards constructing stuff is electronics. I have only just scratched the surface of it. I want to make a power source out of a coil and a magnet inside (electrical induction). Can anyone point out how exactly to build the thing? My desired output voltage is about 5V, or sth. I'll use it for electronics, so the amperage doesn't really matter. I would also like to see a circuit that converts AC to DC, cause the coil will give out only AC and that's not good. Thanks in advance!
Topic by 5ar | last reply
Did you guys see this! I bet one of you could make one too! Pretty cool! Enjoy! Someone Built A Real-Life Thor's Hammer That Can Only Be Lifted By Its Creator http://www.iflscience.com/technology/youtuber-builds-real-thors-hammer-electromagnets
Topic by BLASTFEMI | last reply
I have several very powerful rare earth magnets that I use in a physics laboratory to construct DC motors. Accidents happen frequently, especially when taking out and storing the magnets. Right now I just use some plastic separators in between each one, but even then the magnets tend to fly off and grab onto another, usually taking with them some skin. I've been thinking of making a box to hold them. Can anyone think of a good design or materials? Thank you. PS. Yes, I've asked my class to come up with a method. Nothing great so far :)
Question by blakeredfield | last reply
So I finished a new speaker I designed, today. It was just then that I thought about the possibility of creating a new design. In the tradition speaker, a coil sits below the magnets, and they are pulled in and out of the coil, creating vibrations (subwoofer).I like this method, and all, but I wanted a bit more! So I got to brainstorming. If you were to put a coil around the magnets, it would still work - it's just have no bass what-so-ever. Well, what if we were to put a coil on the bottom, as usual, but add a second coil on the opposite side, while allowing it to encircle the magnets, but not get in the way. So when the magnets get pulled into the coil, the second coil does not interfere, but still is close enough to the magnets as to create sound. Would this have any adverse effects? Would it ever work? I've included an image so you can see my vision. I may very well just be stupid, but hey, it's an idea. Going to work on it tonight.
Topic by freethetech | last reply
This project is for my 8 year old daughter that is in grade 3. She has to build a magnetic powered car (and not from legos or hotwheel type cars), that can go fast or slow, and extra points if the car can turn left or right. I'm at a loss, can someone help please ?
Question by weirdmoss | last reply
Hi all,I am wishing to add some sort of dynamo to my bike to power lights. The main reasons are if the batteries get low I will forget to change them, and I will probably forget to turn the lights on. So off I went to eBay and bought a Â£4 generator and light set. It arrived and today I have been attempting to fit it - to no avail. I have a mountain bike with full suspension so there is no where suitable to fit it to.So back to the drawing board. I came across FreeLights. The idea itself looks promising (unlike their spelling), however their implementation probably wouldn't be any good for me as it appears to be aimed at thin framed bikes - hacking probably could be done, however I would like to roll my own solution, and create an Instructable in the process!So anyway, if you are too lazy to read the webpage above, here is how it works:- A magnet is attached to the spokes- There is another magnet in a container- The container has wires around it- The container connected to the forks so the magnets brush past itBasically it is like a cycle computer sensor, but it produces lots more electricity! I like their idea, but it seems rather inefficient as the magnet is just randomly spun hoping for the best. They offer a kit version which appears to use a spherical magnet, but even so it still seems rather inefficient to me. So on to two other possible options. The first is basically the same idea, but the magnet is fixed so it can only spin in one plane. Something like this [Ultra-simple Electric Generator]. The other option is to get rid of the spinning magnet, and instead just have coils like the various wind turbines on this site.So basically I want to know which method is the best, and given that how I can maximize the power produced. I am thinking just increasing the number of turns, stronger magnets, greater number of magnets on wheels, greater number of 'generators' etc. And then realistically, what sort of power I would be able to get?Cheers, Luca
Topic by TheLucster | last reply
Earnshaw's theorem states that a collection of point charges cannot be maintained in a stable stationary equilibrium configuration solely by the electrostatic interaction of the charges. This was first proven by British mathematician Samuel Earnshaw in 1842. It is usually referenced to magnetic fields, but originally applied to electrostatic fields. It applies to the classical inverse-square law forces (electric and gravitational) and also to the magnetic forces of permanent magnets and paramagnetic materials or any combination, (but not diamagnetic materials). Earnshaw's theorem has no exceptions for unmoving permanent ferro-magnets. However, moving ferromagnets, certain electromagnetic systems, pseudo-levitation and diamagnetic materials are areas to which Earnshaw's theorem doesn't apply and thus can seem to be exceptions, though in fact these exploit the constraints of the theorem. Can we develop a safer cleaner transportation method that involves electro magnets that can propel cars using the city's grid to adjust the power on the street or road to move cars. similar to famous movies vehicles like STAR WARS(c) Repulsor Lift(c) technology or The MATRIX(c) Ships OSIRIS?
Topic by daswokster | last reply
I am building an electric generator similar to one found on a wind turbine. It will be turned by a number of things; the main purpose is just to generate electricity. I need to know what type of magnets to use with the coils, should I go for one with greater pull force of more gauss on the surface field? What other specs should I take note of? Any help would be appreciated!
Question by crocboy | last reply
I made a quite intersting discovery today.The use of mixed orientations for a stronger or more directed field on one side and a much weaker on the other side of a magnet is nothing new. But if you check modern wind turbines or even just any old hard drive you find "chokes". I talked about shielding before but combining shielding a choking provides again another level of manipulation.If you ask anyone who claims to know magentic field or sience in general then you right away hear: There is no such thing as magnet with just a single pole!Like a battery one pole can't exist without the other!Keep going and your conversation parten either get angry or declares you a nut case.Also said before: The laws of nature and physics are not set in stone or complete for that matter!We only use what we know, or to be precise what we told to take as facts.A magnet with just one pole is impossible to manufacture, if you only think like making the magnet like any other magnet.Even cutting it in half will only give you two normal magnets again.Why is that so?How are magnets made is what you need to know.No matter the material they start as a blank and during the final processing an intense electromagnetic field is used to "prime" them.Like you would do on a screwdriver the material then keeps the "charge" and becomes magnetic.And this process requires a certain orientation.Imagine a big hydraulic press to make the magnet with some super strong electromagnets right beside the forms.Explains why you won't find a block magnet with the poles on opposing corners - the form is not designed to be rotated ;)Ferrite magnets can often be machined.If you mark the field direction of a block then you could just cut it into the shape you need.Like a half moon, triangle, pyramid...The orientation does not change, so you need to create the cuts so your required orientation matches the orignal block.Creates a lot of waste, is messy and often the magnets shatter.Still not possible to create a mono pole ;)But it allows for a great deal of field manipulations.For example a thick north and a thin south pole would show very different field strengths at the poles.How to create a mono or single pole magnet then??If you think outside modern science restraints it is suprisingly easy!You see, unlike a battery the magnet does not care if the "current" flows back to its own pole or a pole from a different magnet.In a hard drive the choked magnets have a field strength between them that is not just twice as much as th one from a single magnet.The field between the magnets is very stable too!No matter where you measure it is the same.Place two magnets in the same configuration with the choke and all you get between them is a mess.To understand the reality with magnets I need to explain a bit more though:If it does not matter from where to where the field lines go the it becomes obvious that you can guide them.Horse shoe magnets of the old kind where just two steel bars with a block magnet between them!Take a compass and check from what distance your magnet will start to affect the orientation.Now take two iron bars, rods, block or similar of about twice that length.Place the compass between one end and the magnet between the other end.Even with a little gap your compass will still move!You just extended the length of the field lines and directed them somewhere else as it also works with odd shapes.We know know and confirmed how choking works and as shielding is basically the same thing but for a different purpose you might get an idea where I am heading already.A "potted" magnet, like what you find in a speaker or as a hook magnet utilises two destinct features.a) A ring magnet is used.b) The field lines are directed to a specific area.One has them directed into a gap for a coil like in a wind turbine, the other to the surface to massively increase the field strenght in that area.If you take either apart you will notice the magnet just by itself is considerably weaker.Removing a pole from a magnet...If you paid attention so far and have a few magnets around then you already developed a feeling for the difference.Lets crank it up a notch, shall we?Make this experiment:Take two identical magnets and a soft steel bar or similar of lesser thickness than the magnets.Usually around 2-3mm for smaller N52 Neodymiums will do.If you dare make the steel the same size as the magnets.Now place one magnet on the steel and use the other to observe the difference in feel.There won't be much and both poles should still fell like before only that the field is now slightly longer.Trying to get two magnets to touch at the same pole is really hard, but see what happens if you add the other magnet on the other side of the steel...Despite having the same pole on the steel they won't repel and stick to the steel.Checking the field now with a magnet provides a very different feel!It is like having a magnet with a split pole where the opposing pole now is in the center.Impossible I know but you have it in your hand, so deal with the explanation yourself ;)And if that is so damn easy then how hard can it be to actually remove one pole fully?Design of the impossible magnet...If you want the south pole only then it would be the entire surface of your impossible magnet.That means you either need to make sacrifices or get creative for the next steps.Easiest from my experiments is to sacrifice like all scientists do and allow for some minor gaps.I won't give any dimension or step by step instructions.Think 3D and use your imagination.Our impossible magnet starts from the center.All magnets used should provide the same field strenght!To be precise it means no matter their grade, the the "force" of the magnets should be as close to identical as possible even if the size is different.You can use stacks or different types/grades...The center is a square block of soft steel, or iron as pure as possible - it needs to have a low "resistance" if you compare them to batteries and to avoid confusing terms.On this "dice" you place one magnet on each face, preferably of identical size to the block.So, for a 10x10mm block you use 10x10mm magnets -simple isn't it.All magnets are place with the same pole onto the block!In out example to get the south pole outside you would use the north pole.Now use six bigger magnet blocks for another layer.This time they are placed in attraction mode, meaning you let them stick together naturally.The resulting magnet will be far from perfect but you will have a hard time finding a strong attraction to the soth pole of a magnet if you move it around your cube.If you check the geometry you will now see how 45° degree angles and matching sizes for the blocks would be beneficial.Using ferrite magnets you can machine them to the desired size and use a thin aluminium or breass frame to hold the outside properly together, like edging on a fancy tranport box or chest.Check the magnet now and try to find anything else but a destict south pole on all faces and corners.No more nother pole....Does that mean it really is a mono or single pole magnet?Since modern science does not even consider a construction like this to be worth testing you already know the anser.For those working on a different level with magnets it will be a true single pole magnet.For the rest it will just be another fake.As by science a permanent magnet is defined to have two poles and to have field lines going from one pole to the other.All modern machines using them operate on this principle and "fact".But if I would give you a block of steel that has a core of lets say brass and a suffien wall thickness...Then this block would appear to be a steel block and nothing else.Modern science fails to see a magnet any other than a battery!If the "current" does not need to go back to same pole and there is no need for the field lines to go back to the outside pole then it is a single ple magnet like the faked box is a steel box.The physical outcome or in our case magnetic field is what defines it!The contra...All good has some bad, magnets are no different.Purely scientific viewed it would be impossible to create a gap free magnet like I described.And because never all field lines will take the shortcut there will still be a small amount of "north pole" to be found on the outside.But if that is in the range of about 1% of the field strength of the magnet then I say it can be neglected for almost all real life uses of such a magnet.Like the Halbach Array it is just a neat way of manipulating and if you like bending the known interpretation of our scientific understanding.Possible uses for these magnets exclude convention designs and for this reason alone anything you create with them will be the target of scepticism to say it nice.Ok then, what real life uses could there be for something we never needed?The question is the answer, as the impossible magnet is the solution.Ever watched these shopping shows in the night program?"It solves problems you didn't even know you might get..."Means that if you ever get the ide that your project requires a single pole magnet then you know how to make one ;)All I can up with would go against common scientific understanding and teachings, so I will spare you with my use cases ;)And what is missing here to actually make it work?Quite a lot as you might have noticed in your experiments if you use really good test equippment.Not so much however if you consider what I said about shielding and choking ;)Provide a path of far less resistance and shield the rest that still bothers you.I am not providing a ready to go model here that you can buy, someone else will do that if they see a financial gain it.My gain is provide a new understanding of things we forgot by giving your brain things to work with and develop.You might still say in the end that my way (or your results) are not good enough in some way.But then please also consider how many other people or documents you might be able to find that would have provided you with this information.Free energy is only a myth for as along as we allow ourselfs to only trust what modern science allows us to have.Allow the old knowledge in and every now and then simple ignore what you know and things become possible sooner than you might think.Wind and water were used as a source of free energy since the dawn of mankind.Our first motorised boats used the same "wheels" we already trusted to be driven by water to power a mill, saw or similar.And after we learned about motors we also found a way to make wind - by reversing our trusted wind mills into a fan.Instead of using the free energy to generate power for us we evolved to use create wind and propulsion by providing power to drive the same thin in reverse.Using the sun for power other by using a mirror was seen as witchcraft throughout history, then we got solar cells...Same for heat in the form of peltier elements and other things...Why then should magnets be any different??Just "Because it is so!" did not work for wind, water and solar, not even for heat....All it takes is a little notch in the right direction to change the way we think about magnets.We have no problem using electromagnets to make a motor spin.We have no problem using magnetic field of any kind to drive motors or generate electricity.We even fail to have a problem by manipulation electromagnetic fields for that purpose.But we struggle like an ant in sand hole to reach the surface again to see what is outside our trap before something grabs us from behind when it comes to permanent magnets.Even worse if you dare to claim your magnetic machine delivers a higher output energy than what you use to make it run.And wasn't it exactly the same ignorance and manifested "knowledge" that got revised so many times throughout history already?Again: Why should magnets or their understanding of interaction be any different?If you follow the above with just matching magnets and the core cube then the result will be at least very surprising to you.Allow this surprise to be an inspiration to improve instead of seeing as a proof of failure ;)And if you made it then please post about it here.Let me know what disappointed you with the outcome.Let me know what really got you wondering.Let me know if you found a suffiently strong north pole to rival the impossible southpole! ;)Start sharing, make other people wonder and make them share it to, let us go viral!The first to post a conclusive Youtube video with results is certain to get a lot, lot, lot attention....
Topic by Downunder35m
Hello all! Made this topic to start a discussion about my latest project: 3D printed Magnetic Connector. Here is the link to my project: https://www.instructables.com/id/3D-printed-magnetic-connector/ What would you change? What would you add? I am waiting for your suggestions!
Topic by kondzio29 | last reply
Hi Everyone I have a problem! I am trying to find a way to make a Rube Goldberg project where I have fake lego man with magnets on his hands and feet with acrobat bars that "swing" back and forth and the man is suppose to clip to the next bar of increasing strength of the magnetism till he gets to the end of platform on the other side. I problem right now is I am trying to find a set of magnets in increasing/decreasing strength to finish the project but I have no idea where to find them. If any one has any ideas I could really use some right now! I have concept drawings! You would have my undying gratitude. Thank you!
Topic by seerofsorrow. | last reply
Question by SissyDale23 | last reply
I am planning to build a tesla coil, and eventually a really big one, and when I don't think I could get a long enough roll of magnet wire. Would it be possible to simple twist or solder two ends and then enamel them or something and still have it work, I know the coils are supose to be flawless.
Question by jj.inc | last reply
I am trying to attach some led lights under a shelf and also need to make them removeable, i need to find something that is conductive as well as magnetic. My original idea was to just get some small nickel or ? plated screws and just wrap wire around them and screw them in but not completely sure of that idea working. I already made the lights and have small neodymium magnets that im going to attach to them but just need some ideas of what to use for under the shelf....thanks Ive thought of clay, or glue and other stuff but idk. im putting 4 lights up. and there will be a switch to shut off power to the material when not in use so there's no safety issues.
Question by ARGMISTER | last reply
Question by ThejasV | last reply
Does the wire gauge (20,24,28,30,34,36 wire gauge) make a difference is the strength of the magnet? Does the voltage I supply to the coil effect the Electromagnet??? Shall i use 304 grade steel rectangular bar for this process ? if any other materiel please suggest me?
Question by babureddy | last reply
See on net all time about free electricity with magnets. want to know if anyone has had success with this or is it even worth trying to build.
Question by WayneLong | last reply
Instead of using compressing of gas using combustion and passing gas and using spark plugs ..... shall we use a dipole magnet in the place of spark plug and and a magnetic piston with a pole on top side.if we rotate the magnet at the spark plug place ,when the opposite pole comes down .......the piston due to attractive force goes up and when like pole comes up it will get repulsed and goes down by this crank can be rotated.this is basically based on the principle of magnetic attraction and repulsion........ i am just a college student its just an idea that came into my mind......please say whether it is possible or not...
Question by Ramadossk | last reply
Hi I was playing with some ideas and wonder if it is possible to get power from a moving piece of aluminum. I know, if you tab the alu, you can get the power because to the eddy-currents geenrated if you have a permanent-magnet near... But what if i wanted to get the power NOT from the aluminum, but from the "other" side like the magnet? If i hold a magnet near a moving piece of aluminum, can i get power from the magnet as well or are the eddys only generated in the alu and not in the magnet since it already has its magnetic field? So the basic question is: How to get power with the help of a moving piece of aluminum, but the tab-point in NOT the aluminum but something geometrically separated. Thanks a lot! :)
Topic by Orngrimm | last reply
When someone starts talking about a so called magnetmotor than most people judge right away.Laws of physics, perpetuum mobile is impossible, magnets are static....We all know the limitations nature puts on us... That however did not stop quite a few people since the 1950's to build working magnet motors. Or, to be precise: To make the claim, show them and then somehow disappear. A few though seem to have survived and even claim to make good business. Securely closed machine, stellite tracking and 24/7 online monitoring. Either just a bad and long running hoax or a real attempt to keep a secret secret. Even the somewhat famous Yildiz motor showed off around the world only to disappear.Some like them, some don't. Either way all this sounds like the perfect conspirary theory LOL So lets take a look on what is fake and what might be real but missing some vital clues. You can find several good Youtube channels created by people trying to build a working magnet motor. Some of them have no problems to admit failure and still keep trying and updating their projects. Did long enough and you see two outcomes. The first is giving up or "realising" that it will never work. The second often seems like a user is getting some relly good results and is really close to keep the magnetmotor running. Both disappear without and updates or traces. Now of course this is just confirmation that it will never work, but then again: What if it did already quite a few times? Even Tesla had patents for a magnetmotor and so far none of his patents were a hoax. Although none of his patents allow to actually build a working devices without some additional info and knowledge. And that is the key that I am trying to get: The lost knowledge.How can a magnetmotor never work? That one is quite simple from the start. If a linear model won't work no matter where you start then a rotary version will fail as well. And if a linear version works, it has to do so far at least 5 segments and with preferably increasing or at least constant speed. Having said that and assuming you know a little bit about magnetism: Ever wondered about shapes of magnets?? The common types are block, round like a bar and those disk like ones, some even with holes. A less well known version is the ring magnet. You can look them up as well as their corresponding magnetic field geometry - or what is assumed to be the right geometry. To give you a clue: All those floating spinning toys use a ring magnet in the base and onother one in the spinner. In the center is a dead zone for the magnetic field that is far lower than further out on the ring. And the strnger outer fields also reach further - giving the entire spinner a bowl like area to float on, the spinning just stabilises it like a gyroscope. A similar flat disk magnet wouldn't have this indentation in the field but rather a dome like sphere. The ring just kicks a dint into this sphere if you don't mind the simpification. Similar changes in the field structure happen when you combine two or more magnets. One example we all know is stacking identical smaller magnets. And often we are suprised how much stronger two thin disk magnets are compared to a single. Distance however sets a certain limit. And take those hook magnets... Just a small ring magnet in a metal pot with core. Remove the magnet and just by itself it is far weaker. Why? Quite simple.... The same way a transformer core directs the magnetic flow, the metal part of the hook magnet provides a shortcut for the magnetic field - and in return all is much stronger ;) Now you have some more clues, but still there are tons of options for failure... The most common is the sticking effect. No matter how well you planned and designed in most cases you linear or rotary prototype will stall sooner or later. Even if started manually at high speeds some seem to run very long but once they slow down and stop it is obvious they always stop where the magnetic field won't allow the binding effect to be overcome.Wouldn't dare to say that I have a working magnetmotor, but I might have some clues you want to try if you decide to give it a try yourself. So how COULD a magnetmotor actually work? Like in the Perendiv examples all over the web, you could aloow a moving responder to the rotor. Like a piston the responder will be lifted in areas it would otherwise limit or reduce the speed of the system. Well designed only a few mm would b required but it also means wasted energy to move the responder. Then there is the nice way of modifying fields by adding magnets in different angles and polarities. Lets say towards the end of your stages on the linear model it is hard to overcome the binding effect from the end of the previous stage. The perendiv model would now somehow change the distances. But you can also add magnets to lower the binding effect ;) Like a ring or hook magnet you can shape the field and offer a stronger repulsin field or a lower binding force. Last but certainly not least is the option of adding magnetic metals like iron or somehow weirder ones like bismuth. So, do we have any examples of something very common utilising any of this? We sure do :) Take a speaker apart and you end with the cage, the membrane, the actual work coil and the magnet. We don't need anything but the magnet so take a good and very close look. What in the audio world is called a shield to prevent the magnet from messing with things close by is exactly the same as on a hook magnet ;) Only difference is the tiny gap for the coil. The magnetic field is directed into two paths, one by the metal core, the other by the inner enclosure of the magnet or the magnet itself. The coil operates in the area of maximum flux.Last hints... If you take two identical and strong magnets with north or south facing up then it is quite hard to push them very close together. But check what happens if you try the same wen both soth poles (or both north poles) are placed on a magnetic surface - if in doubt your standard fridge door. Suddenly you can move much closer together with the same amout of force (not considering the added friction!). And similar story for opposing configurations. Where in free air or on a table the magnets would just jump together, on a metal plated you can move them much, much closer before this happens. Copper pipe and magnet fun :) Ideally you would have a straight copper pipe and a cylindrical magnet that has a loose fit in the pipe. Aluminium pipe work too or even a roll of aluminium foil if you have nothing else. A magnet in the pipe will travel very slow down the pipe, friction is not an issue here. So what is slowing it down? The magnet creates a field in the pipe and through that the pipe generates electicity. And funny enough this electricity creates an opposing magnetic field in the pipe - the magnet slows down. Even if you glue it onto a wooden stick it won't rush through it. Trying to push it by hand and you feel the created resistance. The faster you push, the harder it is to push! If you made it all the way down here with the reading then I have to assume you fit into one of three of my categories. a) You are a total sceptic and just read it for your amusement. If so, then please don't post a reply with usual negative feedback, instead see it as the same fun you had reading it ;) b) You are at least curious and like to play with magnets. In this case take the above as inspiration to explore more ways to have fun with your magnets! c) You are more or less frustated because you wasted a lot of time and some money to build a magnet motor that just won't work. A and B might go on and enjoy the fun, C however might want to read very attentive now ;) If you take some indicator sheet for magnetic fields, like these funny green ones, and play with moving magnets then you see a very interesting effect on the "screen". The otherwise static field lines change chape and sometimes even seem to disappear or shrink. With a small rotor assembly it almost looks like flashes when the magnets move past each other. This effect is often totally neglected and to be honest I overlooked it for a long time as well. Being able to see how the magnetic field changes gives the thing an whole new dimension so to speak. Creating a magnet with a complex shape is difficult to say the least. Only ferrite or ceramic ones can be used and you would cut of machine them according to your desired shape and with regards to the orginal center of the magnetic field. So most people revert to the classic way of shaping by adding magnets of various types, sizes and amounts. Modern neodymium magnets make this trial and error process easier as there are many sizes and strengths available. Add a detector shield of suitable size and you have hours of fun time ahead of you. But doing so in any rotary assembly is next to impossible. So what did Yildiz differently and what was missed so many times? Yildiz took it a step further and not only provided "shunts" to create very strong magnetic field from the generated electricity but also a second rotor. Since we all start small lets focus on the basics first. Remember the hook magnet and speaker or the copper pipe? Some examples for shape shifting your otherwise static magnetic fields: 1. A magnetic metal "connection" from one (low in the armature) pole to an opposing (high in the amature) pole with cause the field from the "high" pole to "bend" towards the connected magnet. 2. A magnet with an orientation of 90° to the last magnet is the sequence will severely influence the field of this last magnet! This goes for either orientations! 3. Adding a non-magnetic "shield" around a magnet, like a piece of copper pipe, will not affect the static field of the magnet. However it will severely alter the field of the enclosed magnet when another magnet passes it! It will also affect the overal field during the passing as the moving magnet will also induce a field in the copper by affecting the field of the enclosed magnet! Thickness and lenght of the shield influence the strength of these effects. 4. In a simple perendiv motor design the bar that creates the attraction for the spinning part is a magnet too. Either a long bar type or two small ones with an iron or nickel rod between them. There is no need for a piston or something that drives the bar up or out of the way ;) Just use the right magnet at the right spot on your rotor to repell the bar ;) Mount the ar with suitable springs and you suddenly can have multiple stages on your rotor instead of just the usual one! Don't forget the moving magnet on the opposing side of the segment in question though as otherwise you still will get stuck. (Hint: You can place a small but powerful magnet in the center of the opposing bar ;) Just make sure you limit the springs movement so the bar won't be pulled closer)Ok, hold on now! Does a magnet motor actually work or not? I can only give hints and say the laws of physics as we know them apply to magnetmotors the same way as everything else. Unlimeted motion without supplying energy is not possible. Limited motion with adding or using energy however is still possible and real. The same is true for being able to machine, 3D print or otherwise manufacture at very tight tolerence and accuracy levels. This includes bearings or bearing systems with very little friction losses. Just check these floting and rotating magnet toys that look like a spindle. Only a tiny needle like pin makes contact with a glass surface - next to no friction loss. A proper and supposedly working magnet motor should provide more energy than what it uses - one way or the other. No law of physics lets us get around the fact that such a motor could only keep spinning if the produced power or motion energy is at least the same as what is required to make it move. Magnets lose their strenght over time, they are like a very slowly depleting battery. So, isn't it funny that all magnet motors so far that claimed to work also had the requirement to replace the magnets once the things fails to work or start? And if you leave a very strong neodymium magnet shielded from outside fields or magnetic stuff than your grandkids will still find a quite strong magnet. Do a little performance test with your new magnets, like how much force is required is required to lift them off a steel plate. Make the same test with the magnets once you played around extensively with them in your motor. Now take a spare magnet that was never used from the orginal batch and compare both against each other ;) If the motor would not use energy then why are the magnets depleted to a certain degree, realted to runtime and usage time? Wait a minute! Does that now mean it actually works? Lets just say energy is certainly used. We only know similar effects from electromagnetic systems. But did anyone ever really check how much actual energy is in magnetic field generated by a non electric magnet? Get a good sized N52 neodymium magnet and check how much force is required to pull it off a steel surface. Now try to get the smallest sized electromagnet capable of that force and check how much energy it consumes at the level that equals the pulling force of the N52 magnet ;) Makes no sense to even try to compare these you will say now. I just say energy is energy and we were formed to only think in certain ways and don't even try silly things like this ;) To keep the fun up let us imagine we would actually have a similar energy available than what our electro magnet would require. In reality more because we wouldn't have electrical or flux related losses in the metal around the coil. Or is the imagined reality, no clue ;) If true it would mean even a motor with very bad efficiency would be able to create huge amounts of torque. Well, torque is basically acceleration. Which would mean our motor would not just be happy to spin, it would speed up until the bearing fail or the thing is ripped apart. Imagine a dental drill of that size and weight suddenly falling apart at full speed... Every example of motors claimed to be working, that are not fakes, seem to be happy no matter what the load is. It the thing turns a generator than it would have to slow down a bit with the increased load but they don't. With no limited factors otherwise this makes them a fake. Even a perfect motor would have to react to load changes.... Don't we agree that the stronger the magnetic force or field in a conductor the stronger the resulting magnetic and opposing field of the conductor? We use the difference to either drive a motor or take out electricity... But if you take the "open" shielding of a magnet in a changing field than the influence of the shield on the overall field gets stronger with stronger field changes. And properly desinged and orientated they would actually double as a natural limiter for the rotation speed. Once the electrical energy in the shield becomes too strong it will be able to cancel out the field of the enclosed magnet...If we assume a magnet motor is really possible and works with the intended output to keep it spinning or even take energy out: Then what would be possible downfalls that stop this thing happening in everyones garage? We can explore the stars but so far no one bothered to invent anything to visualise magnetic field in a 3 dimensional way other than by simulation. No realtime and true observation like this. The few working technologies that exist rely on sensors, interpretaion and filling in gaps. But imagine something like a detector shield as cloud! And then even better with selctive spacing to get a realtime view of where exactly the field lines go. All we can do is forget our teaching and try it out anyway ;) If by some mistake a magnet motor would really work right away, then chances are high the inventor would wonder why that thing takes off like mad and how to stop it. Unless well prepared it would certainly end in the destrution of the motor. But the inventor would know what to look for in the next prototype. The logical conclusion would be to the couple the energy taken to the speed while physically limittin the free load speed. The other one would be the design the electrical generator around the and within the motor. To even get close to this point you would have to spend endless days and nights working on finding a solution. The closer you get the more disappointment when the final model still fails to keep spinning for more than a few hours. Most people will then accept defeat and move on... Still not saying it actually works but if you made it to this point in time where it could be easier to move on and do other things:Ever wondered what would happen if you "shield" a magnet with a coil? Of course nothing would happen as we know. But try this in some fixed assembly that allows you move another magnet through the field of the shielded one. Perferably witha force gauge or some option to read out the energy required to move it through the various stages of the field. See what happens if you short the coil or add a resistor to it ;) Now if this coild is able to produce electricity then the more we use the more the effects on the required force would change. What do you think would happen if you combine common coil relations of electric motors to a "coil shielded" magnet motor? Right, all these coils would interact with the magnetic fields of the coils they are connected to... And through that with the overall field surrounding the enclosed magnet..... I leave up to you to imagine how these interacting coils could provide "resistance" or "acceleration"/"surplus electricity"...Like they say: You can only find out if you try ;) To keep up the positive thinking: A permanent magnet just sticks to any magnetic surface and does so with the same force. But the real energy loss in terms of getting weaker can almost be neglected. Any electromagnet capable of the same holding force woul require ongoing energy supplies to keep it up. It is using energy the same way the permanent magnet does! The difference is the permanent magnet is not seen as anything that would provide us with energy.... And if it can't provide energy other than passing through coils then why the heck does it keep sticking to the fridge year after year? It does require energy to keep this weight up doesn't it, even if you add a thin teflon disk and oil to reduce friction? ;) No magic, no "free energy" bogus, just plain physics viewed from a slightly different angle than what we learn in school ;) Have a good laugh and a good beer, then read it again and just consider some of the things here that are not mentioned in any literature about magnetism that we commonly use. Now I got you thinking, didn't I ? ;)
Topic by Downunder35m | last reply
Forromagnetic meterials are not just called that for no reason.It comes from ferrous - iron.Iron has the highest permeability at normal temperatures.That means a magnet is attracted to it very strongly.We utilise this for transformer cores, the stuff inside a relay and the moving latch of the relay itself.Like current from an electrical system magnetic fields like to take the easiest route possible.Air is a very bad medium, so any iron close by will be prefered even if it is at a slight distance.You can check with a magnet, a steel bar and some iron shavings - please cover the are with plate first ;)Slightly less known is the option to also guide and extend the magnetic field this way.If you check how far the magnetic field of a magnet reaches and note that distance,then you can add some steel bars or rods at the poles - the field will extend through the metal.The most powerful example of this are the shielded magnets used for hooks or speakers.Except for a tiny area the entire magnetic flux goes through the metal.So in this lefover area the magnetic flux density will my many times greater than what the magnet alone would be able to.What most people don't know is that magnets also interact with other magnets in terms of their fields changing and distorting.The Halbach Array is a good example of this.Seen as a single magnet the array would have one weak and one strong side instead of even strenght for both.Wherever magnetic fields change a conductor can produce electricity or current.This in return causes an electromagnetic field that opposes the one from the magnets.Just drop a magnet through a copper or aluminium pipe ;)Since these distortions are widely unknow to the hobby tinkerer mistakes can happen ;)In the early days of exploring science some people already knew about shielding.And they also knew that certain metals have certain properties.Where it is quite hard to create a good coil from steel wire, copper works fine as it is not magnetic.What would then a copper shielding do?If you have two moving magnets with only a tiny gap then the resulting field distortions are quite huge.A copper shield around the magnet like a pipe would then react to these changes and also create a megnetic field that works in relation to the enclosed magnet.In simple terms it means the shield would let the magnet appear weaker or stronger depending on the field change.A quite old document I found gave some hints on how people thought in different directions back then.It was in regards to the design of a magnet motor by the way.Here various magnets were shielded in tube made of a copper-bismuth-alumium alloy.These tubes were then electrically connected so it created a single loop conductor.The claim was that the resulting electromagnetic field of this ring would drive the fields of the enclosed magnets sideways out of alignment.Like bending straight pastic tubes sideways.This "pulsating" would always happen when the magnetic binding forces reach max and so basically drastically weaken this binding effect.Another document talks about a "magnetised brass rod".A holes of the rod diameter is drilled through a block magnet.Not from north to south but through the middle where the flux is greatest.The claim here was that if that rod rotates fast enough a very low voltage with a very high current will be generated.Sounds easy and interesting enough that I might have to test one myself one day.The best one however is what I consider a hoax or being as good as Starlite.Someone back in 1908 claimed to have created a material the reflects magnetic fields.In lame man's terms it would be like an insulator around some electrical wire.The claim and some pics showed it, was that no magnetic field can pass the material.Or to be correct only a tiny fraction of what would be possible through air.A small magnet inside a longer tube of this material would create almost the same attraction to steel at the tubes ends as on the magnet itself.Measurements showed the field strength would be almost equal to a long mangnet of the same field strength.Imagine guiding the field of a big and powerful magnet through a tube around some corners or other magnets and then end in just a tiny hole for the entire flux...Too bad he never shared his secret formula to anyone knows to mankind.Isolation...Imagine you have an array of changing magnetic fields and quite strong magnets.Then you might face the problem that your focus on the "working" end neglected the other end of the magnet (stack).Providing some iron core material will keep thes field lines contained and away from interfering with your setup ;)But it also allows to use te otherwise unused end of your magnets more directly.For example by guiding to another magnet to affect its field strenght ;)Placing a sheet or steel between two magnets in a setup provides a "shared pole" so to say.If you have a north and south pole on a rotor at a distance of 5mm then a sheet of steel between will drastically weaken the strenght and reach of this combined field.It is like pulling the arch between the magnets down to make it more flat.And at and an angle the resulting field will also be slightly angled ;)Capping...When I first encounter this many years ago I couldn't really make sense of it.Quite complex..If you check the magnetic field lines with iron filings or similar then you notice how they go in a rounded manner from pole to pole.This is because the single field lines are of equal polarity and will dirve apart like opposing magnets.By capping the ends of a magnet you provide a short.Instead of diverting out like mad they will follow the cap and create very intersting magnetic field in return.If both poles are capped it is like pressing the magnet flat but without having a field on top of the oles - only aorund the center part.For this the thickness much must match what is required for the flux density.As a rule of thumb: if the end is still very magnetic then it is not enough material tickness ;)Interacting fields in a tube...This one is quite old too and seemed to have found no usable inventions apart from simple magnetic spring replacement systems.But it gave me some clues about Tesla "earthquake machine" ;)If you place a magnet in a tube and at it's ends magnets with opposing fields to the one inside then you can fix this magnet in place.Push one magnet deeper and the distance from the inner magnet to the other end will shrink the same amount.In this old paper two coils were around the pipe with the inner magnet between them.In this gap and at about the same width as the magnets length another coil was placed.Violent shaking would then create electrical energy at much higher level then modern shaker torches.In return an AC current on the outer coils would cause the inner magnet to move back and forth to create electricity in the center coil.According to the paper possible uses include: core less transformer, measuring minute changes in AC voltages, providing free power from a running motor...The last one had me stumbled for a very long time.Until I considered a different configuration.The whole thing is basically a linear DC motor - with correct timing of course.And in some motors we use permanent magnets.I am starting to wonder what would happen if we would design a rotor magnet like this?The running motor would be subject to constant field changes that affect the rotor.And a normal motor is always "even".By using four magnets instead of one we can push the field really flat.This means the area where the coil would operate (about 1/5 of the magnets area) will have a much stronger field.The resulting torque should be higher by about 25% !!Even a simple two coil model setup should show a significant increase in performance here.Timing is critical here but I tried some calculations based on 8 poles and the required "on times" for the coils.In a standard motor configuration with a single rotor magnet the coil is active for about 12° of the rotation.With a 4 magnet configuration this "on time" can be reduced to under 8° of the rotation to get the same amount of torque.An energy reduction of about 4% if you neglect losses and only think in time.If you think in terms like impulse energy then we are talking of about 15% !Shorter on time but still much higher flux density overall than for the long standard timings.Going the long run now:If you check how most DC motors work then you realise soon that for most one rule seems to followed.Only use one coild pair at a time.This is quite contradictive if you consider the geometry and options.A dual commutator would allow to use a second coil pair with a field OPPOSING the magnets instead of being attracted to it.After all: on you bike you pedal with both legs and not just one...And if you do it professionally then yu do the same as I suggested for the motor - you use the up pull of your legs as well.Doing it brushless only requires amodified h-bridge desing to drive the second coil pair at the right timing.Some will now say that it requires twice the energy, I say that for the same motor size your get twice the torque!Just imagine what that means in possible weight reduction for a motor - or its size to deliver the same torque at the same power levels when a normal motor is used ;)The more poles the more complicate the precise timing but no big deal really with modern electronics.Can it be improved even further?I though long and hard about that one until I considered EMF.A DC motor produces a lot of it when the elecromagnetic field collapses in the the coils.We do not utilise this energy...There is a tiny delay until the released energy levels are at max.My theory is that it should be possible to divert this energy into another coil set.If that coil is not the next active but still within a strong enough field area then the EMF would actually add to the drive of the motor.Only downside is that according to my calculations at least 16 poles would be required to get an optimum result.Way above of what I can create in my little garage :(In theory it should then be possible to reach about 98% efficiency for the motor....
Topic by Downunder35m | last reply
Magnetostrictive alloys like Galfenol are not only quite cheap but also quite possible to produce and machine at home. As it seems that right now I can't finnish anything without being stopped by something else that got my attention I am a bit stuch on all ends now LOL Anyway, I still have a few kg of rare elements like Gallium, Bismuth, Antimony and such that I misused for my testing of home made ferrites. So apart from making some fancy metals that melt at very low temperatures I thought a much better test usage would be to make something that for once has some real world use :) If you look up some of the research papers for Galfenol use or magnetostrictive materials in general you soon learn two things: a) You need a degree or have studied something related to fully understand the technical stuff behind it. b) Finding something that would give you enough info to make something that works as planned is next to impossible. I don't mind wasting some time on melting steel, machining some samples and do some testing but of course this takes a lot of time... So I was wondering if anyone here already experimented with magnetostrictive materials and their possible uses? Apart from micro actuators for minature things I don't have I was thinking of generator use. A lot of things produce wanted and unwanted vibrations, magnetostrictive alloys are capable of transforming them into electrical energy by simply using a coil around the material. For example the recoil of your favourite hunting rifle could in theory charge your dot sight or laser sight/flashlight. Or the otherwise useless vibrations of big machines or rock tumblers can be turned into something to charge your phone. Not to mention impact sensors or flat surface loudspeakers....
Topic by Downunder35m
Designing what is said to be impossible can be tricky, so I will try to give you some tips to reach your goal a bit quicker.A lot of people these days try to start with a wheel.Makes sense in one way as the final goal obviously is something that would rotate.However, considering angles in a rotating system is far easier with a usable baseline!We developed the liear motor well after any rotating electric motor.But only because someone already invented it for us.Making it flat was then more or less about finding a need for it first, like the modern highspeed trains on a maglev principle.If you want to make something move then it makes no big difference if you do it in flat or round.Flat however leaves you more options and much easier adjustments.And you will need a lot of the later...IMHO the best size and option for linear is the N0 model railway system.Tracks are only 3CM wide and second hand carriages to salvage the wheels is cheap.Either way, how would you start?We have multiple choices, like single row of magnets or double, maybe even tripple.Same for the actual magnet orientation.Flat, angled, attracting or repulsing...They all work if you understand how they actually work.Not the principle, the magnets ;)You see, a magnet always has two poles and without trickery both poles will be of even strenght, size, angle to each other and so on.Playing on a small and flat track with little resistance allows to use tiny magnets, like 5mm disc ones.If you follow the common concept of two magnet rows either side at a slight angle then you are half way there.People spent a lot of time trying not only to let the cart being attracted by the first magnets but also to let them pass out at the other end.In case you wonder why:Being able to be "sucked" in means you will have some force pulling on your cart from the next stage.Being able to fully pass through and preferably gain speed, means the cart would go from one set of magnets to the next - motion is accomplished.Let me give you my personal favourites for 5mm disc magnets:1. The rows are at an angle of 4-5° like a slim V-shape.2. Same as above by with the orientation changed by 90°The first basically means you have the magnets facing up while in the second you would have them mounted vertically.Both have good and bad sides and I think it is easiest to start with the first option.Here you would have a row of magnets at a slight angle either side of the track.Lets say it is all pointing away from you, then the north row would be left, south row on the right of the track.If you start narrow or wide depends if you want attraction or repulsion forces to work with.Again, it makes no big difference really, just a different way of operation, most seem to prefer repulsion though thinking the forces are greater - this is not true though ;)A very often copied way of mounting the working magnet (s) on the cart is by placing a magnet with south facing down on the left and one with north facing down on the right of the cart.Here you have the big problem of manipulating fields.The forces are quite strong and it seems the obvious choice but should be left for the advanced classes.Let me try to explain:No matter the site of your work magnet it has a very narrow acting field.Means you have a lot of attraction forces going only downwards and not providing any energy to move your system ;)If you orientate a magnet (stack) so north faces to the right and south to the left on either side of the cart you have more options.If the stack or single magnet has the correct length to match the angle of the magnet rows then a funny thing happens.Assume the outer most magnet is at about the same distance from center as the first magnet in the row.Means the inner most and opposing one is further away and the attraction forces gain the upper hand.While moving along though it moves away from the magnet row and whie still gaining force the last magnet in the row stops the cart dead center.This is the common scenario you see on the web when people try and fail.Now if you change the length of your working magnet and position in relation to the magnets in the row you can use the changes to your advantage.You can add slim disc magnets either side of your stack and observe the change in behaviour and where the cart starts to be repelled or gets stuck.In a bad case it starts fast but then stops with a big wobble back and forth.The perfect balance and size means the cart is attracted once it comes close to the magnet rows.There should only be a tiny sopt of very little repulsion right before the cart takes off.Like a hair trigger on a good gun if you know what I mean.It should then see some accelleration till about magnet 5-7 in a row of 14.From there it should level out and roll trough and keep rolling.I assume your first attempts now get you to the point where you cart start really nice, slows down a bit and seems just to miss a tiny extra push to make it out.It it shoots to the last magnet in the rows and then settles back to one or two before the end you are close!We have now two basic ways of manipulating the magnetic fields in our favour, or to "cheat" phsyics.Closing the gap.You will have realised by now that you need at least two stages for your system to be tested properly.Preferably 3 to get a 120° angle in a rotary conversion, but 5 would make sure there is hickups.This also means distance is now something to play with.Remember the pull before get at the same level with the first magnet in the rows?This is the first force we utilise by bringing the second stage at a distance CLOSE to take over the pull.Close because we don't want it to pull the cart out just like that.It would create a big "bump" and in a rotary system massive and unwanted vibrations.Instead we weaken the last magnet in either row.We still want to keep its pull but not so much the holding force that makes our cart go stuck here.Placing a magnet orientated in the same direction as your rows at the end of the row will change how and where the field of the last magnet in the row goes ;)Just to be precise: If the magnet in the row is north up and south down then the added magnet should have the poles 90° to that and in the same direction as the row.Depending how high, how close and with wich pole you place it the fields will change.You want to lower the locking force by at least 50% here - that will be suffient to overcome the holding force and gives the next stage a good chance to take over.It can also help to provide a sacrificial pole below the last magnet in the row.Again if north would be facing up then the lower magnet would also face north up but with a small distance to the upper manget.Ok, what happens here exactly?If I would want to be precise here you would need to read an awful lot, so make it simple...The lower magnet provides a way for the upper magnets south pole to get somewhere else instead of back to its original north pole.It also means there is another north pole "pushing" the north of the upper magnet more flat at the bottom half.This weakens the field strenght.Distance is key.The added magnet at the end does a similar thing.It provides attraction or repulsion forces that affect the field shape of the last magnet in the row.Imagine you have north facing towards the last magnet:You would push the last bit of the field up while also providing a very sharp end instead of a big round shape.The south pole of the last magnet also gets attracted by this added magnet, even more with one magnet below it.With those two added magnets you should be able to fully overcome the binding effect stopping your cart.It won't start and keep going when you let go of it half way down the track though, you need to start with the first magnet or give it a push to overcome the first binding effect.After that momentum takes over.If it really is that simple then where are all the successful videos about it?They are out there, you just need to look quite long for them.Most people still literally think only linear.A magnet has north and south and we can't change it - but we can...With field manipulations as above and shielding we get so much more than what physics currently dictates.Keep in mind that adding shielding under your rows of magnets will also affect how all works together ;)Some people forget this when using ferromagnetic things way too close to their testing area.Distance is also vital to keep in mind when experimenting.The closer two magnets are greater their forces to each other.You can utilise this for example by lowering magnets that seem to be far too strong in your configuration and cause a binding effect ;)And as said, shielding is nice thing for triack too - imagine what would happen with sielding on the sides of your magnet rows... ;)Make a negative into a positive!Extremly strong binding forces at a certain point in your track design can mean you might be able to utilise it instead of trying to waste it.Added magnets can divert the field to quite some extend.Shielding however can also direct them somewhere else - like in the core of a transformer where it all goes in a great circle.Even strips of shielding connecting magnets from one row to the one on the other side of the track can be utilised.Like that you turn two small magnets into one long one with twisted poles at the end.Provides more field strenght too and makes it good for areas with little to no attracting force to the cart.Then there is bigger design...Some people add a center magnet.With one on the cart and one in the center of the track you can create a cancellation field.The rows bind while the center magnet wants to push.If place where there is still enough forward momentum or even acceleration but close enough to the binding magnets it is possible to greatly lower the binding effect.But keep in mind you need to consider the added repulsion or compensated the field so it is most active towards the moving direction and less strong to where the cart is coming from.Advanced manipulations.You can machine magnets, sandpaper, file, grinder, CNC....Imagine you cut a square dice magnet from one corner to the other.Depending on how you have the field orientation you can end up several variations.But if north faced up in your dice then it will still face up in the cut pieces!Cut a pyramid and you end with a big flat south pole and a pointy north pole - and with extreme field strenth in this pointy bit.Similar story with half moon shapes.Imagine you machine a flat block magnet so you have a half moon with its pointy bits facing down and big round bit up.If north was up in the block and you shape the moon correctly then you end with two strong south pole points and a north pole that is strongest right between those points.Why is this so interesting you might wonder?Imagine you already know a magnets pole does not care if gos back to its own opposite or that of a different magnet.Then you also know you can machine and shape magnets to your will.Now imagine that for a change:Precisely machined pyramids that have the top chopped off.All tops in this example facing being the north poles and big bottom south.If you then machine a precise iron core block you make a nice cube.With magnets we need really good glue and a good press to make it happen.But if the center core is of proper size then we end with a block magnet that has a south pole on all sides.Of course to be 100% perfect we would need a zero tolerance gap but good glue and high forces can come quite close.Works as a sphere too but would even have clue where to start to machine the magnets LOL
Topic by Downunder35m
Dear friends, I want to make a drum with magnetic bars, to capture max matal particals from amixture, size of magnet should be 1200mm*---- ,suggest me what would be the Diameter of wire Regards Nadeem
Question by nadeem Ashraf | last reply
In a physics demo, my teacher used a small coilgun, but it used low voltage AC, not a single high voltage burst, also it used an aluminum ring on the outside of the coil instead of a slug on inside of it. Apparently the AC creates a changing magnetic field, which induces current in the ring giving it a magnetic field as well...
Question by falzarbeta | last reply
Wow, just in time for The Mad Science Fair- an awesome magnetic levitation set-up. The Superconductivity Group at Tel Aviv University have been working on thin-films of superconductive materials and have found some...cool effects. The thin films will apparently have a few defects, resulting in very specific areas where the magnetic field permeates. This rigidly constrains the composite, allowing even "up-side down" levitation! (locked in space, beneath a magnet.) Would be so awesome to play around with but apparently the deposition of the superconductive film is a real challenge, not to mention the sapphire substrate. A forum post at HI Capacity had these links, probably after a member saw Gizmodo's article "What the Hell Magnets? Why Are You So Amazing?" Via youtube: ASTCvideos Quantum Levitation QuantumLevitation
Topic by CrLz | last reply
Rotate cylindrical magnetic bar over circular super cap as it's or short her 2 internal plate (hopefully if we can) to act like one flat ribbon coil nano wire made of carbon instead of copper. nano tech also should be implemented in small medium even large motor/generator and I think it would yield generator with high efficiency low weight and size with minimized edde current and inertia. NOTE ultra caps does not sold in our local electronic store here in damascus syria , if it was i would bought it's and experiment making generator using magnet and super caps and post the result thank you all for your time reading my question :)
Question by infoseek | last reply
For my project I need to know how far electromagnetic fields can reach. I am guessing its related to power and materials, but perhaps there is some kind of rough formula for calculating potential reach? By reach, I mean, how far can the magnetic field reach and attract (move) something, like metal fillings. Also, is there anyway to know how quickly a magnetic field can move something. In other words what speed will metal fillings move at when the electromagnet is switched on? Thanks all, Joel (the snow athlete)
Topic by snow athlete | last reply
Want to see the information on the magnetic strip in your credit card? Just take some fine rust powder and blow it onto the card to see the magnetic bands that get picked up by card readers. This won't help you read the information any better, but it does show you the hidden world in magnetic cards and that's pretty sweet. Another Science Experiment via boingboing
Topic by fungus amungus | last reply
I am currently working on a project that requires energy harvesting ,so i decided to use electromagnetic induction for the purpose. However I can not decided how to design my magnet and coil combination. All i know is i want 2.6-3.3v and 26mA for round about 4 ns. The setup in brief required a movable permanent magnet and a stationary coil. The moment of the permanent magnetic is like a oscillating pendulum just for once but with a sleed of say about 15km per hours. So can you please suggest me how should i start designing. thank you
Topic by SiddhantS6 | last reply
A permanent magnet's magnetism is commonly described as a small molecular effect wherein the the effect of individual molecules is polarised in a way so that the effect reinforces and creates a macro effect throughout the entire material. Is it possible - do you know of any surfaces or materials, real or proposed, that could be considered to be a similar kind of "upscaling of 'microscopic' properties"?
Topic by 8bit | last reply
I'm trying to build a pmdc motor (perminent magnet motor) based on this video: https://www.youtube.com/watch?v=WKklyuzghQg But I want to make it in a much biger scale and instead of using a ceramic magnet I wan to use 2 big industrial neodymium magnets instead they will pull up to 200 pounds. I want this homemade built motor to pull a scooter like vehicle (skateboard if you will). It will be powerd by 2 12V 10A batteries wich doing the math should get me: 12V+12V=24V 10A+10A=20A 24Vx20A=240W The coils will be made from 1.5mm thick copper wire. Based on what I've said do you think the motor could be powerful enough to pull this scooter with someone standing on it at about 20 to 25mph? can this be done?
Topic by NoahW7 | last reply
I stubled upon several mods to convert a standard ceiling fan into a more or less usefull generator.So if you are looking to go this route then I might have some nice improvements that can be implemented.People like these mods for some weird reason, despite the fact that it requires quite a bit of extra work to make them weather proof.However, when it comes to the fundamentals then to me it looks like some folks out there are missing out.On the available power that is...Always the first step for a mod like this is to replace the induction ring with a lot of magnets.Second step usually is to remove a lot of the coils, especially the inner ring.Now, these two stator designs are common for fans with two speeds.Those with three or even reverse might have a different configuration!Lets start on the magnet part:The recommended way of placing the magnets is by creating an air gap as small as possible - makes sense.But then it is always the same amount of magnets as there is coils - and the spacing is also the same as for the coils.In the general generaotr design world this configuration is prefered as it allows for the best performance.If you dare to go a bit further and cosider how the magnets react to the stator configuration then you might want to consider a different option.You see, these two sets of coils for two different speeds mean just one thing:A different amount of poles is created, with the outer ring having more poles than the inner ring of coils.The core is split around the coils, not just to allow the windings to be made but also to provide independent paths for the magnetic field - resulting in the two pole configurations.Amounts differ by diameter, power level, manufacturer and so on.What is always the same is that the inner ring has less coils and that the outer segments of the poles created have even spacings.In the normal mods you see posted these gaps in the core for the outer ring are closed by inserting lamitaed pieces from some old transformer.And you end up with ONE usable coil configuration and ONE power output.The slightly advanced mod uses the inner coil to add some load depending on the speed to prevent spinning out of control in high winds.If you try a normal DC motor with permanent magnets than you will notice the strong binding forces, it is like the rotor sticks in certain places.The better ones use and uneven configuration to reduce this binding effect ;)In my mod the magnets are selected in size to almost be the same length as two stator poles next to each other.This allows for the best induction while still allowing "to experiment".Bringing the magnets and the coils into play...As said an exact match of the number of magnets to either coil ring is not ideal.The prefered option is to go somewhere in between.For example:Outer ring has 18 coils then the inner ring will have 9 coils - exactly half.360° divided by 15 make a nice 24 degress per magnet.But with 12 magnets you get an even 30°, which is far easier to deal with.16 magnets at 22.5° is another option.So, what does that exactly do for us?The bad thing is we get slightly less performance if you only see the standard mod with one coil ring.The good thing we get far lower binding forces and through that the thing will even spin in very light winds.Adding both coil rings with a suitable rectifier however results in a pulsing output of two sine waves.With just the rectifier we get a ripple that is easier to deal with through a capacitor.The extra power available is in the range of about 40% and make more than up for the "reduced" amount of magnets.Going the extra mile once more ;)Having created a much fancier ceiling fan mod now you might wonder if there is not a way to get even more out of it.And there is.For example by utilising a gear system or belt to get a far higher rotational speed on the generator than what the blades would provide, prefably then with quite big blades too and an automatic break for high wind conditions.With the reduced binding forces the generator will be happy to spin at quite high speeds in low winds.Downside is that you will need to build a far more sturdy bearing housing.In return though you get more stability and durability.You can do the math yourself based on the number of poles per ring and magnets to get the output frequency based on the RPM's.Perfect would now be to use a switch mode power supply configuration to directly transform the provided output into a stable DC per ring.And yes, it is possible to use mechanical systems to provide a fixed output speed from the blades to the generator - but way to complex and lossy!Lets do some lame math with no regards to realities:If the original fan would spin at 100 RPM at full speed than we could say our generator should provide the mains voltage at about 100 RPM.Keep in mind we utilise both coil rings and not just the high speed one!Geared and with the blades spinning at 100 RPM we might get as much as 1000V from this little generator....And even with the lower amount of magnets we migh see frequencies above the 500Hz range.The good thing now is that normal iron core transformers can still operate at these frequencies.A bit lossy in the upper range but acceptable for the purpose.Put simple: A 10 or 20:1 transformer per coil ring would provide us with a far more suitable output voltage and much higher amps.If you made it to here than you certainly wonder about other magnet configurations.Checking the stator configuration you will by now realise why I selected the magnet lenght accordingly.The magnets "activate" one coil after the other.The spacing between them means there is always some overlap where the magnets only cover one half of the stator for a coil.This is ok because we don't really have to worry about the resulting messy output.Ideally though you would want to have a magnet activate both coils, the inner and the outer at the same time.What we did though was to make sure that at no time more than ONE magnet fully covers more than ONE coil!It is the best option to cover both coil sets while minimising binding effects and increasing the avialable output.To go the last step you would need to invest a lot of time re-winding all coils :(You don't want to do this unless you have the means and no friends and family that might miss you for a few days....I found a far simpler way to change the coil configuration, although it is not as good a re-winding.So let's go full scale shall we?Ceiling fan reconfiguration!If you take the usual 18 to 9 configuration than one thing jumps to mind reight away: 3-phase power!Cutting the wire that goes from coil to coil might not always be possible and if it is then you need to know how to handle it.Magnet wire can be hard to solder.Burning the coating off results in corroded copper that is even harder to solder.If you are lucky though than a reall hot soldering irong will be able to melt the coating.The flux from the solder will start to cover the wire from the cut and the solder will follow.If not then using some fine sandpaper and time is the other option to remove the coating...Ok, you seperated all coil and have two wire ends per coil?I hope you did not cut off the ones going out to the actual connections to the outside world ;)Properly solder each wire end and take your time to check it is really proper and not just a few spots.Mark or number the coils on the rings!For the inner ring we have 9 but need only 3, so we start at one connection to the outside world and check if this connection is on the outside or inside of the coil.For this example I assume you picked the one that goes to the outside of the coil.Connect the inside wire to the outside wire of coil number 3, assuming we start with 1 here ;)From the inside wire of 3 you go to outside of 6 and the inside is you first new output connection.Do the same with the remaining 6 coils and where needed add the required output wire.It really helps to have wires with three different colors here, one color per new coil set.Note which color corresponds to to the three coils used!!!The outer ring with 18 coils is sightly different here.You see, we want a "flowing" magnetic field that makes best use of the new coil configuration!We can not simply bridge them in any way we feel like without considering how this might affect the electrical side of things.As we now take the approach of a three phase system it makes sense to use a more suitable magnet configuration as well.So before go to the outer ring of coils lets have a look of the best option for the magnets first:The stator packs are evenly spaced in our example and will alow us to use 18 magnets.This provides the best performance with the downside of a higher binding effect, but we need this configuration to get the best possible output.As said at the start I selected magnets that are just shy of being the same length as the corresponding stator segments.In a "free" setup these magnets would now be quite hard to place in a makeshift ring.Even harder in the original casing.A 3D printer certainly helps but some common sense too ;)Wood is easy to work with and if you select the right stuff than making a suitable ring to hold your magnets and attach to the drive system metal parts is not too hard.Bar or brick type magnets can be quite easy be utilised on a wood setup :)The key is that you add Flux Capacitors - sorry couldn't help the reference to Marty....What I mean is to add some magnetic material between the north pole of one magnet and the south pole of the other.Lets say your magnets are 15mm long and have a spacing of 5mm.Then a little plate of 12mm would be next to perfect.This plate needs to connect the magnets on the backside, the side facing away from the coils.Use a dremel tool or what you have to first create slots for the metal strips or bars, then the same for the magnets.Glue in the metal first and once set add the magnet, making sure the always go north to south with their alignment.Ok, and what does this do for us?I hope you are not one of these persons who starts building while reading...What we created now is a shortcut for the magnetic forces.The field between the magnets is severly compromised in terms of being usable for the coils.We do get a much soother run though...I only did that to have some fun and check if you paid attention - sorry :(What we really want is an effect similar to what you see on a loadspeaker magnet that is still in its metal shielding.A ring magnet with one pole on the inside and one on the outside is used here.The shielding provides a path for the magnetic field that is not going through the speaker coil - hence the little air gap for the coil.If we do the same then our efficiency will be going up quite a bit.Take two identical steel parts, like some butter knifes, and prefarbly a force gauge.If you try to pull your magnet at a 90° angle from the blade you will get a certain reading for the required force to lift it off.Most people now think that this would be the max a magnet can hold.So take the other knife and place the magnet between them.If you pull the knife off with the gauge now the reading will be higher than what you get from just the magnet ;)Taking that to our model and keeping the field lines in mind we now know that we could even use slightly longer plates if our magnets happen to be a bit short :)Just place them right behind each magnet !Back to the outer ring of coils....With 18 magnets we get an even system for both coil rings.However we want to make sure that our output waves are syncronised and not at random order.We need to combine two coils to be back on a 9 coil configuration as on the inner ring.The other option is to provide two sets of outputs for outer ring, resulting in 3 3-phase outputs.Both have their pros and cons....But if you check the 18 magnet configuration ina ction over the coils it becomes clear that combining two coils the usual way is possible but also that our inner ring does not get a proper north south action from the magnets!Only the outer coil ring works properly!For the inner ring we never get only a north south combo, instead a lot of mixes.Did I mention to read first? ;)Of course we can only use 9 magnets in our configuration, but at least I did not traick you on their size....You see, we need to account for the fact that the coils are not just evenly spaced but also that all configurations in terms of coils to stator pack are doubles or halfs.Makes a lot more sense if you know how these asyncronous motors work :)With 9 magnets we actually get both inner and outer ring coils activated properly.Plus we now have the benefit that there are always twoouter coils in sync with each other.Means apart from the same way you wired the inner ring you make this addition to the outer ring:"One" outer coil is created by going from one coilinner connection to the outer connection of the second after this, skipping one coil.The resulting output is again just 3 phases but with double the output voltage.The key is to again take notes of how you connect and wire the coils - and the colors used for the output wires!Let me give you an example for the correct order:I we take the number 1 coil on the inner ring then coils number 1 and 18 would be next to it on the outer ring.You want to combine 1 and 3, 2 and 4, 5 and 7,....And you want the resulting three coil packs and wires colores to correspond to the inner coils in the same order!That is true for the always same way of combining coils from the inner to outer connection - or the other way around but never mixed!Ok, we have done the magnets and the coil configuration now properly, no jokes this time!With two simple 3-phase rectifiers we get two DC outputs that can be combined or used seperately.As we end up with roughly double the output voltage on one output but all coils are the same it makes sense to treat them independly.For those who wonder why:If you add a load than one coil system would take a higher loading of it.Meaning while one coil set is stll fine the other will already start to overheat - if the load is too great.So we use two rectifiers with some filtering.In the basic form just a really big electrolytic capacitor of suitable voltage or a full LC filer system with multiple stages.Either way we can now utilise some better DC-DC converters to get going.Considering the equal max watss the coil rings can handle it make sense to include some current limiting.A good converter will provide this option.Both converters can now set to the desiered output or with some added protection diodes and adjusted properly to the same voltage combined for just one DC output.Compared to the standard mod of removing coils and bridgning stator packs the resulting output power in overall Watt will now be about 40-60% higher - depending on the model and quality of parts.Special words of wisdom:Consider the orignal max speed of the fan when used as intendet - see this as a theoretical max output that equals your mains voltage.Just ignore losses and such things - better to be safe than sorry.It becomes clear that it quite possible that your output will be far higher than mains voltage and that you need use transformers for the two 3-phase systems so you can use standard DC-DC converters, which have a max input voltage of around 50V only.This means your converter must be able to handle the higher amps!The fan might have only used 100W or less than 500mA but at high speeds and a ratios of lets say 10 to 1 for the gearing high wind speeds might get it up to over 5 amps on the transformer outputs.Please do the math first for your gear system in relation to the max wind speeds you want to use with your blades!If in doubt use a converter that has some reserves to offer, especially if you aim to charge batteries as quickly as possible.The most vital part however is to ensure that all previously cut wires are isulated properly!!!Magnet wire of the standard kind is good for about 1000V max, so don't drive it higher!Heat shrink with a hot glue liner is prefered but hard to apply in these thight spaces.Since nothing moves consider using long enough wires for your connections so you have enough space to solder without affecting the heat shrink tubes.Liquid insulation or rubber is the last option and should only be used to finalside the heat shrink security measures.Best option once all is confirmed to be working fine would be to make a custom mold and to fully enclose the staotr pack and wires with casting resin or an insulating casting mix.Make sure to keep the output wirese free at the their ends ;)What if I don't want to build a complicated three phase rectifier and just use a single phase system as it was?Firstly chances are your coils are already connected in a three phase configuration, just all in series.But working out a suitable magnet configuration to suit this is much harder if you want to use both sets of coils.In a series configuration like the original you also have to accept the losses from these connected coils.The higher the overall resistance the lower the possible output ;)Main problem however is to get the magnet working properly.The standard 9 or here even 18 magnet configurations still works, especially with the added shielding from behind.But the coils also produce a magnetic field, which grows with the load.Means that an top of all you also have the coils working against the magnets and create even higher losses.Explains why the simple folks prefer not use the inner coil set if they go with a single phase system.So either accept the losses and just use the outer coils or do it fully and get far mor output.And by the way: a 3-phase rectifier modlue is only a few cents more than a standard bridge rectifier ;)Ok, and why do I bother to write all this?People like to tinker but most don't really invent.Following some simple instructions is easy, trying to work it yourself much harder.The reward however is that you actually start to know what you are doing :)And what works for a ceiling fan can be used for these ring style washing machine motors too ;)Anyways...We need to get back our roots.Start thinking for ourself again, work things out instead of just looking them up.If people would be aware that a simple ceiling fan could provide about 3 times the output power of its rated installation value instead of only just about half......Super strong magnets allow real output even without re.winding all coils.And what works here works for other things too.We only learned to use magnets in a striaght way because we can not bend them.But we can bed the magnetic field lines to our advantage!The simple shielding used in this mod is nothing more than a shortcut to enhance the field strenght where it is is needed.By a simple coil modification we basically bet two electrical generators for the price and size of one.Apart from stating how easy it would be to place multiple stators and magnet rings into one generator the magnets itself also allow for even more output.If you ever played with hook magnets or speaker magnets then you know how much stronger they are compared to just the magnet once they seperate after hours of fun for you.Imagine you would replace the single bar magnet with two block magnets that are joined by a magnetic shunt like out simple shielding before.If the magnet blocks now would have a slightly smaller footprint than your individual poles:Imagine you create a hlaf ring shaped magnetic connection between the two blocks that also goes aruond the outer perimeter up to the outside of the magnets surface?I mean the surface facing the stator poles?Damn your imagination is good, yout it right away!Of course we would then have a magnet that allpies its full strength focussed onto each pole of a coil!And of course the resulting field would be far stronger than just using the magnet blocks itself and still significantly higher than just adding a shielding or connection between them.The affect of the next coil coming is also drastically reduced, which in return also increases the efficiency.In terms of numbers:If a fixed neodymium magnet would provide us 100$ field strength as the base point with no shielding (just the magnet blocks alone);A fully shielded and connected system, like in a hook magnet combined with a U-style magnet, would reach above 400% here.....Adding witchcraft to the mix ;)Although I know better I just assume some of you have now a working double-three-phase-ceiling-fan-generator.And that would mean you also have some fans to spare from your long experiments.Modern ignition coils seem to have nothing in common with our ceiling fan or resulting generator.So why do I try to use them anyway?For the ignition only one polarity is prefered so the spark works and travels as intendet.Means the "wasted" energy from the othe half of the pulse seems to be lost.The electronics do a lot here but magnets too ;)The core of the coil has magents at either end, turning it into one long magnet that still has the right properties to act as high voltage transformer system with the coils.The coil appear to be pre-loaded and with the ignition pulse it has to overcome the magnetic field pre-set by the magnets.And when the electrical impulse is off the same magnets also accelerated and increase the resulting fall back impulse - which provides the spark.Unless you have a suitable laser cutter or simlar cutting tech available somehow it will be hard to modify the metal plates of the stator.But if you could...Imagine you could add magnet inside the plates that are inside a coil.The same pre-loading would happen.Does not really help in terms of adding outpur as our rectifier would suffer badly here.It does give ideas though...Shielding works fine for the magnets, same for field shaping.Electromagnets use the same techniques...So why not use some leftlever transformer cores to add more "shortcuts" for the coils?Strips of transformer core sheets added either side of the coils increase their field strenght and result in better output!Three packs either side of the stator pack are usually no problem.Now take your leftovers and do a standard mod.Compare the max output on the same windmill with what you get from my mod(s).The only real magic I used here is that I actually bothered to combine multiple and already used methods to drastically increase the available output of an otherwise utterly useless generator mod ;)Warnings:If you take the above mods serious and to the their extreme than it is imperative to make sure you have safety measures in place!Assume the lowest rating for the magnet wire and if in doubt stick with a max output voltage of 800V.These mods are potentially lethal if you don't follow what is common sense to everyone dealing with high voltages for a living!Most people will start without any gearing or belts and use the wind directly.Even here it is easy to get far higher RPM than what the thing ever did under your ceiling.Without some fixes you will need transformers to reduce the output voltage accordingly.Only other option is to limit the max speed to what your DC-DC converter can handle.Making mistakes with mangets can cost you a lot of time and work, make sure to mark their poles somehow to prevent putting them in wrong.If in doubt then double check!Always keep in mind what the magnet wires and your connections can handle!You don't want any arcs or overheating.Some added electronics to monitor wind speed, rpm's, load and temperature of the coils can turn out vital once you upscale.Before letting your new generator do its thing make sure you tested all to the max!Use a drill or so to speed it up and check the limit regulation for the converters.Measure the actual volts and amps going through your coil sets at assumed max speed and max load.Monitor the coil temp while doing so to ensure nothing is out of limit!You are kidding me here right?A scrap ceiling fan shall provide more output as a wind generator than what was used to spin it as a fan?And of course I need not one but two 3-phse transformers...Pretty clear it is all a fake because nobody could replicate any of it unless limited to what the converters can handle...Didn't I say to think outside normal restraints already?A single phase transformer uses two coils in the most basic configuration.For example one side for 240V and te other for 12V.But some of them are more efficient than other ;)A 3-phase transformer uses 6 coils, two for each phase.And there are plenty of standrad transformer cores out there that would allow us to use this configuration.The worst being the MOT, or microwave oven transformer.Very lossy for a reason but good as an example as these have three core stems ;)Now that you see that you will that a lot more transformers actually allow you to replace the two coils with 6 ;)Ok, but why not use a rectifier first and not use a transformer or two at all?The resulting output voltage will without a gear REDUCTION be much higher than what a cheap DC-DC converter can handle.And at such speeds the effiency would be very bad too.You would need huge capacitors of good quality to deal with the now more impulse like output.And considering the primary side of the transformer does not require anything thicker than the wire on the coils of the fan...Not hard at all to find some suitable tansformers to salvage - or to use some nice ring transformers ;)No kidding around, just facts and possible options you might want to explore.Does that now mean I get free energy?Sure, if you mean you get the free nergy from the energy of the wind at no cost.No if you think a ceiling fan could ever power your house.Internal resistance, size and wire/connection properties set our limits.Not to mention that they are designed to be dirt cheap.If you are in a windy region and assume a realistic 300W minimum output from a 100W fan then adding more stage multiplies this.These fancy upright windmills are not just powerful but also would allow to use one modded fan either end.If big enough and with enough wind force throughout the year you could just add a second or third stage to ech end.With 3 on both ends the resulting output would then be suddenly 1.8kW per windmill....And all from scrap parts with only the costs for the magnets...No wind? Then use water....None of it? Get some greyhounds and build a big hamster wheel :)You get the general idea I hope...
Topic by Downunder35m | last reply
Here's the title and abstract of a preprint that was posted to arXiv yesterday. I have no certain idea of what it all mean, and I'm a practicing physicist! I just find the ratio of unintelligible jargon to English really amusing.Monopole and Topological Electron Dynamics in Adiabatic Spintronic and Graphene SystemsAuthors: S. G. Tan, M. B. A. Jalil, Takashi FujitaComments: 21 pagesSubjects: Quantum Physics (quant-ph)A unified theoretical treatment is presented to describe the physics of electron dynamics in semiconductor and graphene systems. Electron spin fast alignment with the Zeeman magnetic field (physical or effective) is treated as a form of adiabatic spin evolution which necessarily generates a monopole in magnetic space. One could transform this monopole into the physical and intuitive topological magnetic fields in the useful momentum (K) or real spaces (R). The physics of electron dynamics related to spin Hall, torque, oscillations and other technologically useful spinor effects can be inferred from the topological magnetic fields in spintronic, graphene and other SU(2) systems.
Topic by kelseymh | last reply
I have a question for everybody out there. It has been a very long time since I did this type of electrical design work, and for the life of me I can’t remember the principals. I know there are many different ways to generate electricity by using mechanical motion, and converting a motor into a dynamo is very easy. What I am trying to do is to make a brushless dynamo. I have taken my inspiration from a cheap hand cranked torch, and intend to improve on it a lot. In this torch it has a coil which has a flat disk magnet sitting above it. The magnet is spun creating the charge in the coil and is used by the LED's in the torch. What I want to know is how specifically the voltage (potential difference) is created in the coil. My experience of stationary coils is where the magnet is rotated inside the coil. Could someone please explain it to me? Many thanks.
Topic by Batdragon | last reply
I saw this video on Facebook which shows a Ouija board themed cake with the planchette hovering aboard the cake surface and spinning.People have asked how this is done, but the maker is not answering.It looks to me like it must be magnetic. I don't really care about cakes, but it would be cool to make something that levitates and even spins like this. A "haunted Ouija board" would be an obvious application fro a haunted house. So, how would you duplicate this effect?
Question by justjimAZ