### 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!

Topic by Downunder35m

### Linear magnetmotor - the basics for a beginner

Topic by Downunder35m

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

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

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?

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!?

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?

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 currentÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂ¢Ã¢ÂÂ¬ÃÂ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, ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂit takes a lot of transistors and capacitors to do the job of a single memristor.ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂ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. ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂ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,ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂ says Williams. ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂ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 dioxideÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂ¢Ã¢ÂÂ¬ÃÂ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 ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂsitting on a chip tester in our lab right now,ÃÂÃÂ¢ÃÂ¢ÃÂÃÂ¬ÃÂÃÂ 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 !

Topic by Downunder35m   |  last reply