Magnetic Field for hollow core?

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


how far can an electromagnetic field reach?

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


A little magnet experiment for everyone!

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 


Linear magnetmotor - the basics for a beginner

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 


Very old shielding materials and techniques for permanent magnets and resulting possibilities

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


Would You Guys Like a "Wireless Power Kit"?

Hello, This was moved to the forums from https://www.instructables.com/answers/Would-You-Guys-Like-a-Wireless-Power-Kit/ I am the author of the Wireless Power instructable here. [1] Over the course of the past year or so, my instructable has had just under 200,000 views and 600 comments. I have found that many people are actually 'recreating' my circuits and making their own wireless power systems. I was thinking the other day, wouldn't it be great if there was a "Wireless Power How-to Kit," which would include a how-to guide, a solderable circuit, and all the components necessary to make a wireless power system. This would be for all of the people who would like to explore inductive coupling, but do not know where to start. I think this kit would help a lot of people... What do you think? Would you like a kit like this? Any tips for creating the kit? [1] https://www.instructables.com/id/Wireless-Power-Transmission-Over-Short-Distances-U/

Topic by robotkid249   |  last reply


Magnetics software for designing magnet coils?

Dear Instructables, I need to design magnetic coils for a mattress that would emit a uniform magnetic field. Does anyone know of a basic program that would plot flux density over the coils? Preferably free! Thanks! Mike

Topic by Cburg1   |  last reply


Why aren't coil guns made this way?

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


brushed induction motor confusion? [answered] Answered

My father and I are currently restoring a metal-working lathe, however, we do not have 3 phase power to power the original 0.5HP 3 phase motor. We do, however, have a slightly smaller 0.25HP motor. At first appearance, it seemed to be a simple AC/DC brushed motor with a field and winding on the armature. There was no wiring diagram supplied with it, but in one configuration (what appeared to be the ameuture and field coils) are wired in parallel for 120V operation. This did not seem right, since the field coils will be simply shorted across the mains, but I assumed that since we are dealing with AC and inductors, this is OK. It works flawlessly, but reversing the polarity of either the fields or armature would cause the motor to sit and buzz. If started manually, it took off slowly but sounded awful. I need the motor to rotate in both directions and do not have enough materials to do this mechanically. On closer inspection after dismantling the motor, it appears there are 4 brushes, connected together in 2 pairs. They are not directly connected to anything. The 4 wires coming out seem to be just for wiring both field coils in either series of parallel for 110V and 220V operation respectfully. Perhaps even more strange, the 4 brushes are mounted on a centripetal switch, which disengage the brushes from the armature. I was able to make out on the rust that it said "revolution induction motor." So I reasoned out that after the fields are energized, it will induce an electrical current in a few of the coils on the armature, and the energy would flow to the other 2 sets of brushes, causing a different set of coils on the amature to energize and this would initially start the motor. After it gets going, the switch disconnects all the brushes and the motor operates as a simple induction motor. My father used to rebuild motors for a small company, and this is in fact one of the motors he repaired. Although he is skilled at this practice, he does not understand the operation of induction motors and can only figure out wiring by strictly following a diagram or trial and error. I am curious about what this type of motor even is, and how it works! In th meantime, I will research induction motors and how they work, and see what I can learn.

Question by -max-   |  last reply


Jargon ... it's not just for breakfast anymore

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


What is a wavefunction?

In the Physics topic on the EPR paradox, NachoMahma asked about wavefunctions and "collapse."Let's put aside the whole "collapse" issue -- not all physicists agree that it is a sensible concept. NM's comment has a link to the Measurement Problem, and I'm not a good enough theorist or philsopher to contribute to that argument.What is the wavefunction? "Is wavefunction only a convenient way to say it's located somewhere close to here, but we're not sure exactly where until we measure it?""At any particular point in time/space the object is in a definite spot with a definite set of properties, but we can only make a reasonable guess?"No. The wavefunction, spread out over all of space (I'm speaking non-relativistically here, but the formal interpretation applies to spacetime), is the fundamental "thing" in QM. "Objects" are wavefunctions. If the wavefunction is localized (non-zero for a small contiguous set of coordinates, zero everywhere else) then treating it like a particle makes sense. Otherwise, it doesn't; the thing behaves like a wave, showing diffraction, interference, and lots of other effects. My preference, when I talk about these things, is to just call them "quanta." They are not particles, they are not waves; they are their own kind of entity with well defined, if really hard to understand, behaviour.How do I get to that point? Well, quantum mechanics is one example of a "field theory" (electromagnetism is the most familiar classical field theory). The equations we write down (the Schrödinger equation non-relativisitically, the relativistic Dirac and Klein-Gordon equations) to describe how quanta behave are coupled partial differential equations (PDEs), which relate the values (and derivatives) of the field at every point in space to their evolution in time.A PDE which relates the time and spatial properties of a function is either a wave equation (if the solutions are sines and cosines) or a diffusion equation (if the solutions are exponentials). The Schrödinger equation is a wave equation, and we call the solutions wavefunctions. Electromagnetism also has a wave equation, which is how we get radio, light, etc.The difference is that the functions in EM are "real valued:" the value of the field at each point in space/time is a regular floating-point number (the "phase" in EM is determined by the relative values of the field and nearby points). The wavefunction is a '''complex valued''' field -- at each point in space/time, the field has both an amplitude and a phase (or equivalently a real and an imaginary component). This means that wavefunctions can interfere in ways more complex than simply "adding" or "subtracting", which can have quite interesting consequences.You get probabilities by taking the square (norm) of the wavefunction. This procedure gives you a real value, a probability, at each coordinate. When you make a measurement, those probabilities determine which coordinate value you see as the "location" of the quantum. The actual result is random, but that isn't because "we're not sure exactly." The quantum objective does not have a single coordinate location until we make the measurement.How that happens, whether by "collapse," "decoherence," "many worlds splitting" or something else, is a subject of intense philosophical and experimental argument.

Topic by kelseymh   |  last reply


Magnetmotor - really impossible or just supressed?

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


gray water storage to water lawn ?

I live on a  small farm and  was  thinking  of   using  gray water  towater   my lawn and  field. I  have  5 kids   in the  house and we  wash a tremendous  amount fo  laundry.  My thought s were to   install a large   tank  behind  the house in  the edge of the field and  piping  my  gray water  and  rain water from the  house into the  tank  and  use for irrigation. My concerns  are   1. i have heard   that   if you allow    gray   water to stand for   as little as  24 hours   it will  go septic which is bad. What of  you  placed  some  type  of  small pump to circulate   the water  say   three  rounds  minimum   every   eight hours   or  so . Could  this  stop  things  form   going septic 2.the goal is   that if   it is raining  today    i need to store the water  at least a few  days    without   itgoing  septic to benefit me. Any ideas  anyone?

Question by andy1917   |  last reply


Trying to build a Alternator/generator welder?

Ok im trying to build a Alternator/Generator welder. i want it to be able to do Stick, Mig, and Tig. So other words three different circuts on one board. so i can switch between the three. 1. how should i control current: in between the battery and field post or after from the positive post from the alternator? 2. how to control the voltage: same as number 1 between the batt and field or from the batt post on the alternator? Also i understand the consant current constant voltage thing. that will be provided on the three circuts. Right now im just working on the stick welder circut ill ask about the mig and tig circuts later or you can pm if you have any info on them. im just trying to piece this togeather step by step. Any help will be great. and yes i know this is a very big project, and will require alot oof time to do.

Question by dmm1542003   |  last reply


(Help) Looking for some ideas related to electronics or telecommunication

Hi guys. I am looking for some great ideas related to telecommunication or electronics or Information Technology     field, that may target segment of markets, customers or solve problems or them all :) I have brain stormed my mind for about 1 week but still not getting a good idea. Hope someone could help. Thanks.

Topic by ims geek   |  last reply


Cathode Ray Tube and Cloud Chamber Combined - Possible?

Is it possible to build a cathode ray tube and observe the path of electrons in a combined (or linked) cloud chamber? I would want to apply a uniform magnetic field to the cloud chamber but not the CRT so that electrons travel in a straight line into the chamber and are subsequently deflected. Oh, and ideally using materials that were available in 1917! Thanks in advance.

Topic by boroman   |  last reply


Automatic LED light for cordless drill????

As far as I know, DeWalt has not incorporated lights into their cordless drills as some other manufacturers have. Could someone make an LED light which would come on when the magnetic field produced by the drill motor is sensed? Perhaps a sensor taped to the drill body, and a small LED light pointing forward, or a ring of light around the drill chuck? Rufus 123Movies GoMovies

Topic by achanakbhayank   |  last reply


Mono pole / single pole magnets!?

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 


Can a magnetic propulsion system be achieved

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


Question regarding polarisation

Hi guys! Can someone describe me,in simple terms, what exactly is polarisation(Specifically of light)? I am a little confused on this topic.  And how many types of polarisation are there exactly? I mean is polarisation exclusive to optics or is it seen even other fields?  (P.S. Dr.Kelsey, i know you are here somewhere, you raised doubts regarding this topic in my previous question, so i'm sure you will provide answers too this time :) :D)

Topic by charmquark   |  last reply


possible ac motor generator?

Anybody tried machining strong magnets into the armature of say 10 or 20 hp 3 phase motor. do not  know the output if any but if so then running through a transformer that might have output  of  220 that is actually useable for living, working in a garage. i understand it would have to be overdriven  possibly by multiple blades for torque to reach the ness speed. just curious if you think it might work or not be worth the effort. this is a new field for me.

Question by builditbigger   |  last reply


What types of magnets to use for generator? Answered

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


Transformer not behaving...

I hope someone here can help.  I have a AC to AC step down Unrectified transformer, i.e., no circuit board whatsoever.  Primary winding has continuity, secondary wire has continuity.  No continuity between primary and secondary wires in any way.  In short, power goes in, but no voltage comes out.  If someone that knows precisely how transformers work can explain to me how a magnetic field can be generated but no electricity generated on the 2ndary wire I would appreciate it.

Topic by PeterE56   |  last reply


Search and communication software for multiple deep sea drones

Why, for clearly group drone work, like clearing mine fields and searching for an airplane lost at sea, don't we have software that can coordinate a group of drones to systematically work together to thoroughly search a programmed area and either blow up the mines or notify "command" of a "hit"?   I can also imagine aerial drones being used to search for lost hikers or for military purposes.                                                                                                                                                                                                                     Somebody can do this. 

Topic by Chrmngblly   |  last reply


GY6 50 cc chinese scooter won't start. What could it be? Answered

Hi. I bought a 50 cc scooter that was sitting for some time. It's 2008 model and it had around 400 km when I got it. That's pretty low in my opinion. Well at first it was running fine. I mad around 100 km on the first day. Well the second day it didn't start. Thankfully my friend helped me and he said that my carburetor is dirty. He celaned it and scooter started up. I made around 60km on the same day with no problem. In the morning the next day my scooter wouldn't start. I tried to do the same as him. I cleaned carburetor and fuel filter but scooter still wouldn't start. It doesn't start electrically or kick start. It's like 5th day and my scooter still won't start. What happens when i turn it on:  - sometimes it sounds just like a dc motor spinning but nothing happens (there is no cranking sound)  - usually it makes cranking sounds but doesn't start  - when I let it sit for a while (for 30min, 1h, day ...) it makes a sound like it almost started up but then dies Thank you all for help! I would like to apologize for my lack of english words in engines and bikes field (not a native english speaker and I'm not specialized in those fields).

Question by matijalazic   |  last reply


A basic (very basic) description of a Brushless DC motor.

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


Compressor-free refrigerator may loom in the future

. From Compressor-free refrigerator may loom in the future at Penn State Engineering via Slashdot:University Park, Pa. - Refrigerators and other cooling devices may one day lose their compressors and coils of piping and become solid state, according to Penn State researchers who are investigating electrically induced heat effects of some ferroelectric polymers."This is the first step in the development of an electric field refrigeration unit," says Qiming Zhang, distinguished professor of electrical engineering. "For the future, we can envision a flat panel refrigerator. No more coils, no more compressors, just solid polymer with appropriate heat exchangers."

Topic by NachoMahma   |  last reply


Finding a builder to test a prototype

I am working on an item, and it requires a small bit of dimensional lumber, ply, and screws. I am trying to make the plans as specific as I can, but having worked in the engineering field as a draftsman many years ago, I know that mistakes can and do get made. So, I am wondering how I would go about finding someone to test build (without fooling with the wiring and such for the electrical components) my plans to find any errors or oversights, inaccurate or unclear directions, and the like. How would I go about doing that? Is there even a forum on Instructables for people to be test-builders? That would be a great thing if there were.

Question by lancer525 


how to limit dc current at 80A? Answered

Dear Sir,               I have a 48V 100Ah Lead Acid battery pack from which I have to power a electric drive train. I want to limit the current drawn from the battery to 80A & also short-circuit protection feature. Ipreferred MCB for this purpose but it  dint work out well. So I need an alternative for MCB, on searching over the internet I found that DC current limiter may do the job in my condition &. I am newbie in this field. Please guide me through the circuitry which may help me out. Best Regards, Rohit Patel.

Question by rohit1491   |  last reply


Question regarding speed electricity

Hi people! I have another thing which i do not totally understand, so as usual i have asked in one of my favourite sites! :) I always had a doubt on how "fast" is electricity. In our real world, i can observe that it is pretty fast. If i turned on a switch connected to a light bulb, i can see it turned on pretty much "instantaneously". So a question came to mind, how fast it really is? Is it near to the speed of light? So, i did some googling. According to what i have found and understood so far, it is the electric field that carries information and not the electrons themselves. And electric field travels near to the speed of light( of course, depending on the medium).  If that is the case, then from the "textbook" definition of electricity, it is the movement of electrons right? But according to what i have understood so far, electrons move pretty slowly. In DC a few millimeters per hour or so(not having the exact figure in mind, pardon me) and the average displacement in AC is zero. Then how exactly is electricity so fast? I would appreciate it if someone explains it in a simple way, both on speed and what exactly is movement of electrons. :) Update: Okay, so far my questions are answered, and it seems to take off in different directions(like science always does :D). So to stay true to the question posted here, i would like to say my doubts cleared! Many thanks to people who have answered my question, Specially Dr.Kelsey and Josehf , for the information provided! I will post other doubts in new topics.

Topic by charmquark   |  last reply


Hubble Snaps Images of a Nebula Within a Cluster

The Hubble telescope has snapped new images of a Nebula within a cluster."This Hubble image was taken in November 2008 with the Wide Field Planetary Camera 2. The colors in the image represent a range of emissions coming from the clouds of the nebula: red represents nitrogen, green represents hydrogen, and blue represents oxygen."Quick facts :Distance: 10,400 light-yearsExposure Time: 2.1 hoursRelease Date: January 15, 2009Dimensions: This image is roughly 2 arcminutes (6.5 light-years or 2 parsecs) wide.MUCH bigger images and more info can be found here :http://hubblesite.org/newscenter/archive/releases/2009/05/image/

Topic by =SMART=   |  last reply


Anomalous Production of Ozone at a Catalyst Surface?

Anomalous Production of Ozone at a Catalyst Surface?   Hi, I'm kinda jumping in here, so I hope I'm not breaking forum rules . . . While experimenting some years ago, I produced ozone by accident and apparently by the action of an electrical current in a Pt/Ir alloy wire. I haven't been able to reproduce the effect due to a lack of resources, but I believe that it, if it *is* reproducible, might be an 'improved' method for the synthesis of ozone. I should say I *did* try to reproduce the effect but a lack of knowledge of the physics of the PGMs meant my efforts came to naught. But if there is someone out there  who is knowledgeable in the field of heterogeneous oxidation catalysis, I'd love to hear from them . . . Thank you

Topic by HansAs   |  last reply


Power from a moving aluminum-part?

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


Quantum Levitation

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


Is repairing a burned tool/drill motor easy?

I assume this applies to all tools. So, I have a burned out grinder motor (wires). The spining axle 'thing' looks fine. Can't I just re-wound those wires on outer ring of the motor and reconnenct it (good as new?) also I may have scraped (with pliers) the replacement/wounded copper wire when bending it away from center . Will I need to rewind it with another set of wire....have I ruin it given there's some sort of non-conductive coating on the copper wire which I scratched off. I would appreciate any specific advice on reconnecting the power source wires to the wire/magnetic field area as well. Or should I just spend $200 on a new one :)

Question by jimboa2020red   |  last reply


Countdown Timer

Hey guys, first forum post. I have just gotten into the electronics field, and I have made a few circuits that I have read schematics from. There's something I want to make, and it's a countdown timer. This is want I want it to have: Be able to count down from at least 15 seconds and be able to change the amount of time Have some 7 segment displays Use the least amount of voltage possible (ie: not need to use the mains or some 12 volt power supply, id rather use a couple of AA's) Have a relay capable of turning on or off a light. And to be as simple as possible. Because I am rather new to this I would rather a schematic, rather than just some help on which components I need to use, because I don't know where they need to solder to where.  Thanks

Topic by ryanlg   |  last reply


Without Hot Air: Mackay's new Book on Global Warming

My friend told me about a new book by David Mackay. I've added screenshots of two of the really nice graphs he put together in his book. Says my friend:Forwarded Message:David Mackay, Cambridge U Physics Professor and a flat-out rockstar inthe field of statistical inference, has written a book on SustainableEnergy, which he is (as usual) giving away for free on his website. http://www.withouthotair.com/There's also a few slide decks for the overview: http://www.inference.phy.cam.ac.uk/mackay/and a blog: http://withouthotair.blogspot.com/I'm not much through it yet, but the gist seems to be putting realnumbers on the size of the energy problem, much as Saul Griffith hasbeen doing. It's written in his usual style, which is to say it readslike common sense you feel you should have known all along.

Topic by nagutron   |  last reply


Antenna tracker or pointer....calling GPS robotics, UAV and R/C guys...

I want to build a system that can point a directional antenna to a known set of GPS coordinates, because if the base unit with the antenna knows it GPS location and then can have the know data of another directional antenna's GPS coordinated either via Google Earth File or a spread sheet or long/lat's or via another method....also I would like this system to be able to track a UAV or R/C plane/copter as the DIY antenna trackers do as I have seen on R/C forums and You-tube. the initial request is what I desire first....I want to go out into a field and set up this tripod mounted Pan/tilt mechanism with mounted directional antenna(s) and point it to the closest fix antenna of known coordinates, automatically. here is a you tube link for something along the line of what the base unit is and would look like: and and

Question by IdeaVault   |  last reply


Steampunk motorcycles

From The Kneeslider:Steampunk is all about the design and very little concerned with added (or lost) function but some of it would be neat if it worked half as well as you wish it would.That's about my take on it; my aesthetic sense says "ooh, shiny" and "mmm, leather" and "lovely scrollwork there, that would be fun to make" and my engineer side says "but...but...shouldn't those gears be doing something?" In any case, The Kneeslider has a piece on steampunk motorcycles, including the Hubbard Steamcycle, which may eventually actually run on steam, and a German bike that's a one-cylinder, 1440 cc machine with a shovel for a seat. Several other steampunk (or even steam-engine) bikes are mentioned in the comment section, as well. The 1908 Field Steam Bike includes "To progress gently move cut off lever and PRAY" as step 10 of the startup procedure, and this sleek little machine would be perfect for any aspiring steampunk supervillain. And from the nigh-venerable Steampunk Workshop, a piece on Tom Sepe's Whirlygig Emoto, a beautifully-crafted "electric-steam hybrid motorcycle."

Topic by reno_dakota   |  last reply


Help participants submit their data - Citizen Science Contest

The SciStarter Citizen Science Contest is live! This is your opportunity to help millions of citizen scientists contribute to real scientific discovery. Make their experiences better by coming up with solutions to some real annoyances that hinder their participation. To get you started, here is a specific--and very real--challenge sent to us by project organizers. HELP PARTICIPANTS SUBMIT THEIR DATA Background: Project BudBurst engages the public in making careful observations of phenophases, such as first leafing, first flower, and first fruit ripening. Scientists compare this valuable environmental information to historical records and learn about the prevailing climatic characteristics in a region over time. The Problem: Prospective and current volunteers are often unsure if they have correctly identified plants and phenophases. This may lead to them not submit the data they've collected. Other volunteers simply forget to add their data. The Challenge: Find a way to encourage and remind participants to submit data after making field observations. Enter now! Contest closes January 21, 2013

Topic by scistarter   |  last reply


Why "Vortex" for Vortex math and devices?

If you are new to the topic then it might give you a slightly quicker understanding than watching hours of youtube videos.I assume you have seen these various coils that make a sphere shaped magnet spin at insane speeds.They are a good start.You see by normal understanding these Rodin or Vortex coils should not be able to produce a field that rotates that fast.As with a lot of things we tried to use math to explain it in theory and than adjusted the math to match it.Vortex math was born.So how do you explain blue and red to a blind person that never saw anything?I mean in a way they actually know how it would look if they could see?Doesn't work, but we can use a Dyson vacuum cleaner ;)A lot of "tornados" add up to one giant super tornado.Spinning so fast that "all" the dirst stays behind and only clean air comes out.As in nature all the weather cells add up to one that is more powerful than the combined single ones.The tornados that form the term vortex are around the coils.But also around the entire donut as well as every single strand of wire.In any good vortex the rotational speed increases towards the center and bottom of the vortex.You can try that with some floating stuff when you drain your bathtub or sink.Try to imagine and endless tornado that runs around every wire like a spiral.The coil itself adds another spin vector to it and increases the moving speed or the single tornado.Combined it adds up to a very strong tornadoe moving very fast around in the coil pack.As this also creates a rotating field like another tornado in the donut shape it all gets twisted up.Physics as we know it won't fully explain these effects.Vortex devices that produce electricity are usually coils in a special winding configuration and pattern.Like we try to eliminate certain things with basket coils in the HF area a Rodin or Vortex coil tries to utlise these otherwise unwanted stray effects and interferences.Overunity is another term people like to use here but I leave it up to you if such a things is phsically possible with an electrical system.Vortex math tries to explain all these things demonstrated in experiments.However I found two slight flaws in the common approch.1. Only two dimension used.Unlike the coils the simplified Vortex math only operates in two dimensions.A circle instead of a sphere if you like.2. Again, unlike the coil harmony and resonance are neglected.It seems in some cases people try to draw a circle just with straight lines.While in reality you have a never ending, resonant "stream" in three or to be precise four dimensions.Is it the chicken and egg problem?Yes and no.You can only calculate something if you can fully understand it or exactly replicate it in reality.Vortex coils are just way to interpret theories and get some sort of results.And those results are the real problem.We can measure magnatic fields in strenght and direction even frequency.However we can neither make them visible in real time not measure mixed or entangled fields properly.We "see" Mars is our "red planet" but in reality it just the atmosphere, the surface is not red at all in most places.NASA has enough problems to calculated missions to outer space with enough accuracy.Just imagine they would have to do it while considering that around every path our planets make is another spinning "distraction"....That is exactly what Vortex math tries to do while eliminating common math bit by bit.You can see and hear in 3 dimensions.Maybe you are also good in drawing something in 3D on your compterscreen or 3D headset.But how many here could predict the path of a baseball in 3D like they do when watching a game?Depending on your viewing angle you might be way off....Try to know or calculate where exactly the ball is at any given monet in time and how fast it spins in which direction.....Our brains are not trained to think like this!Even if we construct things like a dome we prefer to have straight features.Sure manufacturing is one thing that needs to be affordable.But try to just calculate the support structure if all is actually fully round like a sphere should be.We avoid what is considered higher dimensions as much we can.To calculate a distance in 3D it still seems easier to use two 2D models to add up instead of true vectors.Again only through technology like computer we are able to simulate, understand and actually calculate what we need.Where we ventured around the globe and into our solar system our math was left behind.Finding workaround and good enough approximations still seems the way to go.Instead actually evolving our math to our needs we just add more and more complex formulas and calculations.To fully understand vortex math you need to let go and start thinking in 4 dimensions instead of just 2.Oh, sorry, you might be new to this...Number 4 is time of course.

Topic by Downunder35m 


Solar steam piston?

Right. Still hung up on this whole solar energy thing I've been looking into steam but it all seems: complicated, dangerous, expensive, and all kinds of freakin hassle. I think this is largely because people working in this field now are just trying to plug solar energy into where the fire would normally go, but in many ways light is a lot more versatile, and this might take a complete rethink. So, after twenty minutes of ill-informed and distracted thought, how about this: Two or more pistons, each with a little bit of water or other fluid. Base is thick glass, both attached to a shaft or gear to generate rotation. Concentrated light (like 6 kW worth, or whatever) is shone in through the base of one piston. The fluid vaporises and the piston expands. When it's fully extended the light beam flips over to the other piston. That one starts expanding while the first one starts contracting. you might have some sort of heat sink which is oly applied during the contraction bit. This would be fairly low speed, but should generate a fair bit of torque and would be really really simple. Someone just stole my patent, didn't they?

Topic by SolarFlower_org   |  last reply


Citizen Science Contest - SciStarter

Citizen Science Contest Millions of "regular" people are helping scientists discover galaxies, measure climate change, track species' migrations, monitor air and water pollution, and more through citizen science projects featured on SciStarter.com. Help make their experiences better by coming up with solutions to some real annoyances: stop critters from eating sunflowers planted to observe pollinating bees, help remind volunteers to reset rain gauges and report measurements, link activities to social experiences. Or, dream up your own home-based research project that involves public participation to advance a field of scientific research. The Challenges: To get you started, we've listed four specific--and very real--challenges sent to us by project organizers. These problems impact the experience of the participants, and/or the ability of the project to reach its full potential. Select one or more to solve or come up with your own creative solution to a challenge you face as a citizen scientist! - Create Inexpensive Hail Pads - Stop Critters from Eating Sunflowers - Help Participants Submit Their Data - Provide 1000 cheap, wireless climate data loggers Enter now! Contest closes January 21, 2013

Topic by scistarter 


See What's Really Happening in Physics -- arXiv.org

If you are curious about what "real physicists" do, or what the current "hot topics" in research are, take a scan through the "recent postings" at the Physics Preprint Archive. Started for the High Energy Physics community in 1991 at Los Alamos National Lab under the name xxx.lanl.gov, and with a purely e-mail interface(!), arXiv moved to Cornell Univerisity with its creator in 2001.The archive includes preprints from all areas of physics research, not just HEP, as well as computer science, mathematics, and quantitative biology. "Preprints" are a way for the research community to get their results out for everyone to read, during the often lengthy period (months, sometimes!) between submission to a journal and actual publication. In many fields, it has been traditional for decades that printed copies of "preprints" were mailed out, sometimes in regular batches, between major University departments. That mechanism has been superseded almost exclusively by the arXiv database.Besides these traditional pre-publication journal articles, the archive also often includes conference proceedings, and submission of much older published papers of general interest to the community. There's also (usually in the general "physics" category) a scattering of crackpot nontraditional science papers.

Topic by kelseymh   |  last reply


The Memristor - they've found it!

This came out quite a few days ago, but I haven't seen it until today.HP's Henry Williams and his group have accidentally stumbled upon the fourth fundamental element in electronics - the memory resistor, or memristor. Basically, it's a resistor that changes its resistance with elapsed current flow, or total amount of charge that has passed through it, and retains its resistance even after current ceases to flow through it. From the article:"The classic analogy for a resistor is a pipe through which water (electricity) runs. The width of the pipe is analogous to the resistance of the flow of current—the narrower the pipe, the greater the resistance. Normal resistors have an unchanging pipe size. A memristor, on the other hand, changes with the amount of water that gets pushed through. If you push water through the pipe in one direction, the pipe gets larger (less resistive). If you push the water in the other direction, the pipe gets smaller (more resistive). And the memristor remembers. When the water flow is turned off, the pipe size does not change.Such a mechanism could technically be replicated using transistors and capacitors, but, Williams says, “it takes a lot of transistors and capacitors to do the job of a single memristor.”The memristor's memory has consequences: the reason computers have to be rebooted every time they are turned on is that their logic circuits are incapable of holding their bits after the power is shut off. But because a memristor can remember voltages, a memristor-driven computer would arguably never need a reboot. “You could leave all your Word files and spreadsheets open, turn off your computer, and go get a cup of coffee or go on vacation for two weeks,” says Williams. “When you come back, you turn on your computer and everything is instantly on the screen exactly the way you left it. "Apparently, evidence of memristors has been around for quite a while, but it was only until now, during the age of nano-technological exploration, that we finally have labeled the "strange voltages" we've found in experimental circuits as a result of memristor behavior. The discovery was made while doping Titanium dioxide with some dopant that the article fails to cover. Anyhow, the resistance of TiO2 changes with the amount of dopant covering it. Since the dopant does not adhere perfectly to the TiO2 substrate, the flow of charges (electrons) can move the dopant, and cause it to cover more or less of the substrate, thus changing its resistance. "Williams found an ideal memristor in titanium dioxide—the stuff of white paint and sunscreen. Like silicon, titanium dioxide (TiO2) is a semiconductor, and in its pure state it is highly resistive. However, it can be doped with other elements to make it very conductive. In TiO2, the dopants don't stay stationary in a high electric field; they tend to drift in the direction of the current. Such mobility is poison to a transistor, but it turns out that's exactly what makes a memristor work. Putting a bias voltage across a thin film of TiO2 semiconductor that has dopants only on one side causes them to move into the pure TiO2 on the other side and thus lowers the resistance. Running current in the other direction will then push the dopants back into place, increasing the TiO2's resistance.HP Labs is now working out how to manufacture memristors from TiO2 and other materials and figuring out the physics behind them. They also have a circuit group working out how to integrate memristors and silicon circuits on the same chip. The HP group has a hybrid silicon CMOS memristor chip “sitting on a chip tester in our lab right now,” says Williams."I think this is pretty awesome, considering the current breakthroughs in nanotechnology and downsizing of transistors, memristors would enable a whole new field to be born, and circuit theory may have to be re-designed.Like Leon Chua said, the man who first came up with the idea of a memristor, "now all the EE textbooks need to be changed."These next few years in the field of EE should be very interesting =)Image from Spectrum Online

Topic by T3h_Muffinator   |  last reply


Maximum/minimum ampere input in a circuit, help needed.

To start of my question im going to say i don't know a lot of electronics and that I am norwegian( so please excuse typos in english) :) I have not done many major projects inside the field of electronics other than making a lightbulb light up. using a battery and to wires.. But I am very interseted in electonics ad think it is very exiting to read about.  As my first "real" project i decided to make a "lie detector", altough it is mostly just a circuit that measures the resistance in your skin and makes a beeping sound after how much resistance your skin has( Dry skin = low resistance vs wet/sweaty skin = much resistance). AND I DID IT! i made it work, and i was so proud! Then I realized that it was actually kinda lame and the beebing noise was wery annoying. So I decided to make a display that displayed a value after how much resistance your skin held. I managed to make a seven segment display from scratch. But now I am stuck... You see the circuit gives an output of amps so it will output more amps on wet skin than on dry skin. But I have to "program"  the circuit to make the numbers on my display change. I want preferably to be able to do this without any IC's. So my question is there possible to make a circuit that will allow current to pass through one circuit, but if the current is high enough it will take another way? I tried to use diffrent resistors, but I didnt take into count that electricity only takes the road of least resistance no matter..

Topic by VetleH   |  last reply


Anti-gravity Machine concept

This is a concept I came up with for an idea of an anti-gravity machine.  Let me just state for the record... I do not think this will actually work.  However, while I am quite certain this idea should not work... based upon my limited knowledge of science... it would seem like it could work.  Unfortunately I know I am never going to spend the thousands if not millions of dollars to build this concept to find out. The basic premise of the idea is the use of angular momentum to overcome the force of gravity.  Imagine if you will, a gyroscope spinning at such a high velocity that its outward force overcomes the downward force of gravity.  Naturally, one of the big obstacles is generating the speeds necessary to create the velocity such that angular momentum is greater than downward force. What I essentially propose is a spinning ring that is propelled in the same way as a maglev train.  Using Electromagnetic propulsion or EMP to accelerate a ring in a vacuum by the utilization of a flowing electrical current and magnetic fields may in theory generate the speeds necessary for the force to overcome gravity.  Unfortunately, the power to run such a vehicle and the weight to power ratio are significant obstacles. Two of these rings above one another I theorize can create tremendous propulsion if the angles of the rings were changed.  Using hydrolics to change the angle of alignment of these two rings may create incredible forward momentum.  Once more, such a vehicle would not be limited to operation within Earth's atmosphere unlike jet or other propulsion mechanisms.  In fact, it should operate at peak efficiency in a zero gravitational environment. This is all theory... and I'd love to know if it is indeed as crazy as it sounds.

Topic by DarkRubyMoon   |  last reply


The Newman Motor Challenge !

I was recently approached by someone claiming the old Newman Motor wouldn't be good for anything.Well, I was a little bit offended by this as I already had my little toy version of it as kid.At that time though it really was just a toy for me.Critics still say the Newman Motor is nothing more than some interesting machine.And even the biggest followers will admit it is not a free energy machine, just a very efficient one.I experimented with, what some call fringe science, now for about 30 years.And it all started with math and my interest in unusual ways of dealing with problems.So what's behind the challenge?The original design was suprisingly simple as you can see in the above Wiki link.Just a spinning magnet in a (split) coil.What you don't find anywhere though is real details on the how to.Sure, you need to have some sort of contact linked to the rotation and timing is critical but what does it all do?You can build a drt simple model in a few hours with stuff you might have around already.Quite a few Youtubers are happy to share their creations.The actual challenge is to come up with what Newman really did inside his drum.And also why I think it is not the full potential his machine had.Build a simple Newman motor and check for how long you can let it run on a charge super capacitor.Then sit back and read some of the other magnet stuff I wrote.After that come up with a better design ;)I started to create some 3D models that need testing once I find more free time - should take some leave one day..But for those with little patience and an interest in the Newman Motor I decided to share my current idea:For some it might be really confusing although they know motors and magnetic fields.Those just playing with magnets might have it easier for once as they can pretend they followed my thoughts ;)The original design used two coils and a rotating magnet.If you consider how the magnet creates an electromagntic field in the coils then you have to wonder right away how it can spin.And most designs will indeed need a push start to get going!You can't have electricity produced without the magnet spinning and you can't make it spin without electricity!The current from the battery or capacitor can only flow at the short moment of contact on the axle.This moment needs to be timed "mechanical" as we don't want to waste any power on not required electronics.If you ever bothered to check the timing of a Newman Motor then you realised the collapsing electromagnetic field at the moment of contact actually is in reverse to what the manget has in that position.Unlike any normal motor it means the magnet produces most of the power the coil needs to make the rotor spin!So far for the well known facts, now for my fiction:I would like to call my version the Aussie Newman Motor as all things downunder are just different ;)Here are my current desing mods, that I freely share so everyone can benefit form many years of experimenting to save a lot of time.1. Instead of two coils a not-really-bifilar coil is centered on the axle.The coil is created like two stacked relay coild that have no bobbin and a "dint" to allow the axle to pass through.Without the big gap of the original less of the magnetic field strenght is lost and the coil is far closer to a homogenous magnet.2. The timing done by salvaging a simple DC motor's contacts and brushes.This allows for far higher currents and if the salvaged motor had enough poles also for a very short "burst".3. The axle contact is made with a cleaned steel bearing.After cleaning very conductive copper based lubricant is used in tiny amounts to prevent corrosion and provide a lower resistance.The clear benefit is that with the new timing system a lot more current can flow.Initial tests with a mock up model showed an increase in run time from the capacitor of about 15% already.With proper bearings and a salvaged DC motor I hope to reach 18 to 20% more than the original design.Now why the DC motor if a reed contact or hall effect sensor would be even faster and with less resistence?Neither can handle really high currents without additional electronics ;)Plus of course I wanted to leave the door open for the Aussie Newman Motor 2020.You might now say "Why bother if the above improvements are already so great?".If you followed my elsewhere for a while then you know the Newman Motor is only 2D but I prefer 3D or more harmony if you like.Right now the imagination of people re-inventing Newman's machine is limited.They try to get on the horse from behind - literally.Fancy electronics, machined parts and so on.But they never go 3D ;)You got it? :)There is only two coils!!The magnet rotates, same as the contact on the axle.One set of coils for each contact the salvaged DC motor has.Each set aligend to the corresponding contact.And now you will ask "How do you plan to connect that to a single DC power source?Well, that is why it will be the 2020 model - my time for tinkering is sadly limited because I still need to work to support myself.But if you consider that the original as a good model can run for over 10 minutes on a supercapcitor then ask yourself how long it could run on 4 or even 8 coil sets.And although there is no such thing as "free energy": There will be still space for more coils.Or other coils to just provide electricity that does not power the motor.Critics will now see their chance and state that if we add a load to these additional coils then this will cause a strain on the system.Of course they are correct here.If, however, the load is mechanical then the motor needs to supply basically the same additional energy.Plus all mechanical losses.The question is: How much mechanical load can we add before the motor is down to the same efficiency of a very efficient DC motor? ;)And what if our Aussie Newman 2020 would actually violate the laws of physics?We can calculate how much electrical energy would be required so a given motor produces a fixed amount of torque.Or we can just measure it, the beauty of science...We can do the same in reverse of course.Let's say a mechanical pump would require 500RPM and 100Nm of torque to pump 100 liters per minute.Then we could calculate what sized motor we need to drive the thing and how much power the motor would need.So again: What if the Aussie Newman 2020 would require far less than what science makes us think and still does this job on a simple 12V lead acid batty of 4Ah?Just saying... ;)I hope to have a presentable and working 2 coil system by May, so stay tuned!In case you are faster or even beter then of course feel free to show off your results or to post a link to your Instructable so everyone can verify it.

Topic by Downunder35m   |  last reply


Observing single photons (may be future Instructable)

In a thread on building a DIY Geiger counter, I mentioned that it's possible to do an experiment to see single photons directly with your eyes. This is a lab we did when I was an undergraduate, more than 20 years ago. I haven't done the setup myself since then, so I'm just going to describe it; if I have the opportunity run it again, then I'll make an I'ble.If someone else decides to tackle it, please feel free to write it up yourself!The human eye detects light via a family of proteins called opsins. Different forms of photopsins are sensitive to different wavebands, which is what gives us color vision. Rhodopsin is sensitive mainly to greenish-blue light, and provides us with monochromatic night vision. Rhodopsin works by changing its conformation when it absorbs a photon; that change of conformation allows ions to flow through the rod cell's membrane and generate a signal. The signal from each rod cell is processed through the retina and passed to the visual cortex, where a representation of the visual field is constructed.Human rhodopsin has a quantum efficiency of about 25% (there's a 25% chance a single photon will be absorbed and produce the rod-cell signal). By comparison, cat rhodopsin is more than 90% quantum efficient. 25% QE is sufficiently high to be observable -- a source of single photons can be seen by a dark-adpated person with normal vision.You'll need a steady source of well-collimated photons. A green laser pointer (~532 nm) will do nicely. But how many photons does it generate? A wavelength of 532 nm corresponds to 3.53×10-19 joules. So a small 1mW laser pointer puts out 2.8×1015 photons per second (watt = joule/s). How do you reduce that to one photon at a time? With filters. An ND3 neutral density filter reduces the output light by 10-3 compared to the input, so a stack of just five ND3's in front of this laster pointer would result in (on average) just 2.8 photons per second! A stack of four ND4's would give you 0.28 photons/s on average.If you don't have neutral density filters, you can make a decent approximation, by stacking sheets of black trash-bag plastic. To make this work you have to measure the attenuation yourself, so you'll need a photodetector, something which gives an output (voltage, resistance, current, whatever) proportional to the intensity of light.Once you have your single-photon source, you need to set it up in a completely dark room. If you have access to an old-style photographic darkroom, use it. Otherwise, use thick (3-5 mm) black felt and gaffer's tape to seal any windows and doorframes. Put the laser on a table or stand pointed at your face, with the stack of NDs (or trash bags) in front of it. If you're doing this by yourself, you may want to have a piece of tape set up to hold the pointer's button down. Otherwise, your lab partner will take care of it.Sit in the dark for 20 to 30 minutes. This will seem like forever, so you may want something to help you keep track of the time. A standard CD will be about half finished, or you can get through ten pop sons on your iPod, when your eyes become dark adapted.Turn on the laser. You'll see intermittent flashes all coming from nearly the same place in your visual field; if you turn your head, the location will move in the opposite direction. If you've used filters to get down to a few flashes per second, POV will make them easier to see. At less than one photon per second, you'll see them individually.

Topic by kelseymh   |  last reply


Where do I get my science?

Since joining Instructables at the end of September, I've jumped into several discussions of scientific topics, not all of which are directly related to my specialty (experimental high energy physics). Why should I pose as any more of an "expert" in these different areas than anyone else?Well, I shouldn't (pose, that is). In the interests of disclosure, I thought I'd post some of my general sources for scientific information. I'm also hoping these might turn out to be of interest to other I'bles community members. PhysicsFor current research, I skim the arXiv preprint archives every day or two and see what's out there. These are technical papers intended for peer-reviewed journals, so they are generally not accessible to the lay public.Physics Today This is a "general interest" publication of the American Physical Society, intended for physicists but not for subfield specialists.PhysicsWorld from the IOP, similar to Physics Today. Non-physics ResearchNatureScienceBoth are peer-reviewed journals, but cover a full range of fields, including physics, chemistry, biology, astronomy, and more. Popular Science NewsNew Scientst Generally good, but also includes a sprinkling of non-traditional speculative articles, so be a bit on your guard!Science NewsScientific American I actually get this one on paper, in the mail...I also highly recommend the Science & Technology articles in The Economist. As I've commented elsewhere, they have some of the best (both in language and in technical detail) journalistic coverage of science that I have found anywhere.Update 15 Nov 2008: With thanks to GorillazMiko,Science Daily Books, Books, BooksI read. A lot. Stephen Jay Gould, John McPhee, Oliver Sacks, a wide variety of "popular" science books.

Topic by kelseymh   |  last reply