how do you know the size of the magnetic field with respect to the amount of electricity?

For example you have an electromagnet and it has an electromagnetic field how can you know how much electricity to put to make a magnetic field with a specific size (like this many volts equals this many meters in diameter)

Question by HassanA32   |  last reply


iPhone app typing fields not working

Hi. I just downloaded the Instructables app to my iPhone 4 running iOS 6.1. When I try to log in, I am unable to select the typing fields to enter my username and password. I tap and tap and tap, but nothing happens. I've tried restarting and reinstalling and got the same results. Any help? Thanks.

Topic by DELETED_tgee2   |  last reply


Electromagnetic field generator

An electromagnetic field generator strong enough that can disturb the tv signal of your neighbour next door

Topic by SalemSnaKe   |  last reply


Unified field theory?

I was windering if someone could tell me how to add gravity to the Unified field theory? thanks

Question by RelyNupon   |  last reply


Linear Magnetic Field

I am stuck in my research,please tell me a way to make a linear electromagnetic field,other than making an outer core for it please help me

Topic by ajose4   |  last reply


Tablet as a field monitor?

Have anyone come across a tablet that would have a HDMI input? Or a hack to make one? I mean there are lots of 10" monitors but none of them have a screen as good as a cheap tablet.

Topic by DainiusG   |  last reply


Light field camera

Came across this interesting camera that fuses the images from multiple lenses. https://light.co/camera  I suppose it is a "light field camera" as described here https://en.wikipedia.org/wiki/Light-field_camera Any suggestions on possible solutions, or links to similar projects? Prefferable that uses lenses from disposed of smartphones. 

Topic by mskogly   |  last reply


Field of view of a lens?

Hunting through the attic I found an old 35mm projector. I wondered what governs the field of view of the lens system - for this projector it is obviously about the size of a 35 mm slide but for my video projector it must be considerable bigger although the lens looks similar. (I know hat isn't a very scientific judgement!)

Question by rickharris   |  last reply


Magnetic field redirection? Answered

Hi, I've never seen a community so welcoming and intuitive than the instructables community, so I decided this website is the best place to ask my question. I'm sure there is someone hidden deep within the fathoms of instructables that is versed in the matter of magnetic field redirection. I'm working on a project that I will post an 'ible of, (truly wireless speakers ;)) but I need some method of redirecting a magnetic field so it doesn't interfere with the speakers. I have heard of some methods, i.e. Mu metals, MagnetShield, but these are not easy to come by, especially in the UK. I have considered ordering from the manufacturer, but I am not willing to pay the exorbitant shipping costs. I would firstly like to know if such a material exists, or if alternative/better/cheaper methods are available, secondly, whether or not it can be procured in the UK, and if so, where, and thirdly, proper application of such a material. I have done lots of research into the matter, but have been left fruitless. I'm sure someone can help.                                                                 Merry Christmas,                                                                                             icyseptember

Question by icyseptember   |  last reply


Can any intangible thing manipulate electrical flow?

Like is there anything non-material, like a magnetic field which when brought near a wire or by any other way stops or allows the electric flow through it? And I am not talking about a changing magnetic field producing a current in the wire.

Question by Wisaam   |  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


Is there an airsoft field in northern Utah?

Is there an airsoft field in northern Utah. Specifically near Park City?

Question by piepieburger   |  last reply


Strawberry Fields Forever - The Beatles

LET ME TAKE YOU DOWN CAUSE IM GOING TO STRAWBERRY FIELDS NOTHING IS REAL AND NOTHING TO GET HUNG ABOUT STRAWBERRY FIELDS FOREVER LIVING IS EASY WITH EYES CLOSED MISUNDERSTANDING ALL YOU SEE ITS GETTING HARD TO BE SOMEONE BUT IT ALL WORKS OUT IT DOESNT MATTER MUCH TO ME LET ME TAKE YOU DOWN CAUSE IM GOING TO STRAWBERRY FIELDS... NOTHING IS REAL AND NOTHING TO GET HUNG ABOUT STRAWBERRY FIELDS FOREVER NO ONE I THINK IS IN MY TREE I MEAN IT MUST BE HIGH OR LOW THAT IS YOU CANT YOU KNOW TUNE IN BUT ITS ALL RIGHT THAT IS I THINK ITS NOT TOO BAD LET ME TAKE YOU DOWN CAUSE IM GOING TO STRAWBERRY FIELDS NOTHING IS REAL AND NOTHING TO GET HUNG ABOUT STRAWBERRY FIELDS FOREVER ALWAYS, NO, SOMETIMES, THINK ITS ME BUT YOU KNOW I KNOW WHEN ITS A DREAM I THINK, ER,NO I MEAN, ER, YES BUT ITS ALL WRONG THAT IS I THINK I DISAGREE LET ME TAKE YOU DOWN CAUSE IM GOING TO STRAWBERRY FIELDS NOTHING IS REAL AND NOTHING TO GET HUNG ABOUT STRAWBERRY FIELDS FOREVER STRAWBERRY FIELDS FOREVER, STRAWBERRY FIELDS FOREVER...

Topic by FunkNattidelic   |  last reply


Long range magnetic field?

Hi,right now i am stuck with my research.I want to make a long range magnetic field 14 m (approx) please help me 

Question by ajose4 


WWII era field phone: Answered

I'm looking for alternative uses for it. Right now I just imagine calling in an air strike when whataburger takes 20 minutes on a solitary chocolate milkshake. I've heard of people fishing with them but I'm a sporting man and that method doesn't seem very sporting. Unless of course we are in a WROL situation and I need to feed dozens quickly. Short of those two weak ideas, I'm stumped.

Question by tandem25   |  last reply


Make a magnetic field detector ?

I dearly want to make a device to measure electromagnetic fields in the house ,since the presence of such has been more than obvious and at times annoying . My CRT monitors behave strange in my room . The geometry of one bends as i turn the monitor in one direction and at the same direction ,my spare one changes color to blueish like pale . Interestingly, they do it in the same direction no mater where i put them in the room . My turntable's (i am in to Hi-Fi gear ) cartridge reacts when i put it in some places in the room and i hear noise come out of the speakers until i reposition the turntable . Anyone have any ideas how i can locate the source ? Some simple device ,or schematic that will give me the ability to measure ,or at least detect to some degree the fields responsible ? Will be thankful for any answer .

Topic by soundsmyth   |  last reply


A challenge of sorts: Field Kitchen

I want a military style field kitchen.  Not the giant 30,000 dollar trailers, the small but efficient kind towed by jeeps with 60 hp in the world wars. It has come to my attention that even these are quite expensive, not mention rare. I want to basically make a clone, except perhaps make it light enough to push by hand (should be possible by replacing non-essential heavy materials with light ones) and make it propane powered. Hopefully on a budget of a few hundred dollars. Any suggestions are welcome. A base/ pre-made trailer or cart to build it off of, material reccomendations, and most importantly how to implement the the cooking part. It needs tot be able to house 2 30 gallon pots and griddle top. pic is more or less what I'm aiming for

Topic by Bando_Red   |  last reply


Adding a field to mention cost?

I think I have read many instructable pages and don't see that users mention the cost of the project. They do mention what materials and spares were used and where to procure them from, but I think that the uploading user should be requested to mention the  cost under the instructable, so that a new reader gets an idea of approximately how much money it is going to cost him apart from the time he has to put in. A new field at the end of the instructable whereby the users may enter cost of each item listed or the total cost of all the items in the project. This will greatly enhance the instructable pages. Thanks.

Topic by greatidea   |  last reply


Waveform of pulsed magnetic fields... Answered

I have recently been astoundingly interested in magnetic fields, for seemingly no reason. The point is, that in reading up on it, and being a big fan of the greatest mind of all time, Nikola Tesla, I have been stumped with a question that I can't quite seem to answer, and can barely wrap my head around. My question is this; when one takes a normal electromagnet and sends pulses through it, is the resulting pulsing field considered to be longitudinal or transverse waves, or something else all together? This has baffled me, and I am curious to see the answer. Another question I have is, what exactly does Tesla mean by "hertzian" waves, I'm assuming that that his "non-hertzian" waves are longitudinal waves, but I could be wrong. A little background on the question... This question arose when I was looking at the 'ible "spooky tesla spirit radio"  (something along those lines, I'm not sure the exact name). I read somewhere in the comments section that Tesla found Hertzian waves to be, for lack of a better term, a waste of time. This brought the question of different waves up, and one thing led to another and here we are!! Thanks for any and all answers!!

Question by arhodes18   |  last reply


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


A Visit to Simon Field's Farm

Last Thursday my friends Quinn and Xander invited me along on a visit to Simon Field, a chemist, inventor, and entrepreneur. He lives on a small farm in the mountains south of San Jose, with his wife, a couple of alpacas, some goats, and a great many chickens, parakeets, and other parrot-like birds. And a tree house with a rope bridge going out to it, where he occasionally hosts parties. And a solar cell array from which they get most or all of their electricity. And a huge redwood tree, which someone in the '60's rented out to live in! And a hillside spring which under the right circumstances can shoot a fountain 30 feet into the air. And an art studio, and many artworks of various sorts just set here and there for one to stumble across. And a lot of salamanders... Check the image notes for details. Inside, his house is filled with science toys, spilling out from his workshop.  I had to make a separate forum topic on those to treat them properly!

Topic by rachel 


How to program gravity field? Answered

I am working on a program to learn about OOP (object oriented programing) and I want to make a program that lets you create planets and fling them around a sun. Here is the current code. Note, I am always actively changing it so the code may be broken at the time you click to open it. Sorry if that happens. https://www.khanacademy.org/computer-programming/solar-system-creator-oop/4441139047 =========================================== I know the gravity formula is F = (G*M1*M2) / R^2.  The problem is that F is a scalar, not a vector. I need to split this equation into X and Y components. But apparently, you cannot just simply define the X components and Y components separately using that formula because it is not a linear/inverse relationship. :( Anyone know what the easiest way to make gravity vector field?

Question by -max-   |  last reply


Simon Field's Science Toys

On my visit to Simon Field's farm, Simon showed my friends and me a great many awesome tricks and toys.  Of course, Simon does run Scitoys.com so this isn't surprising!  First we saw his workshop where he spends his time doing research, inventing things and writing books about them. He showed us a trick of floating aluminum pans off of a Tesla coil which I sadly did not get any pictures of. Next he got out a small vaccuum chamber and set some marshmallows in it. Yes they expand awesomely as the pressure declines, but what happens after that surprised me. Take a look: He also had a board which he had painted with homemade phosphorescent paint, made from ground-up strontium aluminate (I believe it was).  You could "draw" on it with a laser pointer: Here is an example of Franklin's bells, an electrical demonstration made famous by Benjamin Franklin.  A small metal clapper is suspended between two metal bells, each of which is hooked up to one end of an electrical circuit.  If sufficient voltage is passed through the circuit, the clapper is attracted to one bell, touches it, releases (or obtains) electrons to become similarly charged, whereupon it is repulsed.  It is then charged oppositely to the other bell and is attracted to it, until it touches that bell and swaps charges.  The cycle repeats as long as the circuit is maintained. The last thing we did was to eat whipped cream... that had been frozen in liquid nitrogen!  This turned Quinn into a dragon.

Topic by rachel 


EMF [electromagnetic field] shield fabric?

Does anyone know how to make EMF [electromagnetic field] shield fabric?

Question by lindaoak   |  last reply


Can a Singularity Exhibit an Electrostatic Field ? Answered

What is wahh.......  a small black hole ...........  that's a singularity. If you bombard  it  with electrons ( which carry a negative charge ) will the tiny Black hole be attracted to your pet cat.   Cat fur looses electrons easily and acquires a positive charge.

Question by iceng   |  last reply


Airsoft field weapon for about $200?

Im a "n00b" , as some people would call it, to airsoft. Im looking for an aeg with 350+ fps, good accuracy and range. I prefer the m4 family of weapons, something that gives you that tactical look.

Question by zack attack   |  last reply


Track, Field, and Cross Country experiences

Hello everybody! This is knexsniper1 with a brand new forum for everyone to share their experiences! This time it's about athletics; cross country, track and field to be exact! In this forum, I would like everyone to share their experiences while competing, or just for fun; about the mentioned topics. you may share your fastest times in the 100 meter, farthest long jump, tallest high jump, but these are only some of the things that you can share. the choice is up to you! You can also use this forum for tips on competing, or you can share your ideas on how to compete better. Those of you who compete in these sports will have their name displayed here, and stats about them, such as their fastest times etc. Remember! I want this forum to be as "clean" and appropriate as possible, so don't be calling anyone a loser just because they can not run as fast as you, or jump as far as you, or anything! Just to start this forum off, I will be the first one to post my experiences on this! You may share anything you wish! some of my goals include competing national, and then moving on to international, beating the world record for high jump, and beating bolt at 100 meter! Have fun! knexsniper1: - 1 mile run: 5:27 - 100 meter: 10.62 Kiteman: -did an eight minute mile cross-country. That's a thirteen mile cross-country half marathon in less than an hour and three quarters. Smokedasphalt: -timings and distances: 100meters : 10.8s 200m : 22.1s Long jump : 7.08 meters. Triple jump : 13.76 meters. High jump : 1.80meters. Other achievements : Best athlete of the under-19 category of Pune city. Plus, loads of medals!! :D Now, I only concentrate on the 100m and long jump. Hope to participate in the internationals one day!

Topic by knexsniper1   |  last reply


how to make a good relation between magnetic fields that formed by electric fields and magnetic force ?

How to make a big magnetic force if we have a Direct Current battery, a solenoid, a magnet?

Question by puteri salmiati   |  last reply


where are airsoft fields near lyons,NY?

Where are airsoft/paintball fields in upstate NY

Question by aseaheru   |  last reply


Shallow depth of Field... From a tiny lens?

It is a nice effect to open up the aperture of a camera, focus on the subject, and allow the background to go blurry.  But many of today's still and video cameras have a tiny aperture. How can I get shallow depth of field from such a camera?

Topic by Toga_Dan   |  last reply


PEMF device that mimics earth's magnetic field?

I am very interested in making a pulsed electric magnetic field device that mimics the Earth's own magnetic field. It could be as simple as one single coil. That coil would have to have a magnetic field that measures in the 30 to 90 microTesla range, and it would have to be able to be pulsed in the 5 to 45 Hz frequency range, since that is roughly the strength and frequency of the Earth's own magnetic field Any ideas on how to make that happen? I am a reasonably intelligent person, but I am not necessarily technically gifted. So for somebody this might be uber simple, I don't know, but I am just not sure how to go about doing this. What do you think?

Topic by lapis lazuli   |  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


Debevec 360 degree light field display

I know some of you may have seen this already, but it's still pretty spiffy.You gotta love Debevec's projects. I do, anyway.

Topic by royalestel   |  last reply


fiber optic star field without attic?

Is there a way to make a fiber optic star ceiling without an attic??

Question by tim13211   |  last reply


Battle field 2:modern combat for ps2

Does anyone have a battlefield 2:modern combat for ps2 online account?If you do than leave a comment for everyone else to see. My account name is Alpha95 spellt exacaly like that. knex htr htr.OUTTTT

Topic by knex hater hater   |  last reply


6th Sense Device (To Sense Magnetic Fields)

I saw a program not too long ago (I believe it was from the UK) about an experiment that was done in which they outfitted a participant with a device that contained a magnetometer, as well as some number of vibrating motors mounted on a belt along his waist. It was designed so that overtime, his brain interpreted this incoming data as a "new sense" which allowed him to literally FEEL the magnetic directionality of the Earth. I'd really like to try this for myself, but am no good doing electronics projects from scratch. (I need guidance)  So is there anyone here who is up to the challenge of attempting this, or can anyone at least show me how it might be possible to create this myself.  I'd love to augment my senses full time and become a super human. haha Thanks in advance for any and all help. -Nick

Topic by foxymcfox   |  last reply


about programming emf (Electromagnetic Field) detector

Excuse me, I would like to inquire about emf detector. I saw one of the projects in makezine.com make emf with arduino, with LED bargraph. but here I replaced it with a small audio (8 Ohm), but why not come up with the perfect voice? This is my remake program   if(val >= 1){                    val = constrain(val, 1, senseLimit);     val = map(val, 1, senseLimit, 1, 1023);      total -= readings[index];                  readings[index] = val;           total += readings[index];                  index = (index + 1);                        if (index >= NUMREADINGS)                    index = 0;                               average = total / NUMREADINGS;              if (average > 50){                tone(10, 50, 100); delay(1000);     }     if (average > 150){              tone(10, 50, 200); delay(1000);    } if (average > 250){ tone(10,50,300); delay(1000);     } if (average > 350){ tone(10,50,400); delay(1000);     } if (average > 450){ tone(10,50,500); delay(1000);     } if (average > 550){ tone(10,50,600); delay(1000);     } if (average > 650){ tone(10,50,700); delay(1000);     } if (average > 750){ tone(100,50,800); delay(1000);     }         Serial.println(average);     delay(updateTime);   } } void tone(long duration, int freq) { duration *= 1000; int period = (1.0 / freq) * 1000000; long elapsed_time = 0; while (elapsed_time < duration) { digitalWrite(pinSpeaker,HIGH); delayMicroseconds(period / 2); digitalWrite(pinSpeaker, LOW); delayMicroseconds(period / 2); elapsed_time += (period);   } } please answer. Thank's.

Question by dzikriyana   |  last reply


make a magnatic field and use only four 1.5 volt battreris

 i want to make a magnatic field only use only  four 1.5 volt battreris(4*1.5 volt).who can lift the 500 kg wait only for two sec, this megnatic field i can aply only 6 sqr inch plate only plz send me the digrame if u can.

Question by urosameer   |  last reply


Don't you just hate field trips? Comment on this topic if you do!

So, next week my class will be having a field trip to CHINA! FOR A WEEK! I mean, C'MON! I HAVE TO BE WITH MY CLASS, RESTRICTED TO WHAT I CAN DO, FOR 7 FRIGGIN DAYS! *Swears like crazy* LOL I spazzed out.... So, who here hates field trips?

Topic by Camisado   |  last reply


How do I capture the collapsing field of a coil so I can use it again?

If I energize a coil and then switch it off, I get a collapsing field, I would like to capture this field and use it to energize a seperate coil, is that possible, and how would I do it. Thanks.

Question by joecarey   |  last reply


If a person can feel magnetic fields does that mean they have electromagnetic hypersensitivity? Answered

I want to know cause I have a reletive who can feel magnetic fields from magnets.

Question by nerd7473   |  last reply



is there any airsoft fields where there's no age limit in sanders county, mt?

I want to go airsofting, but I'm just about 11, so, are there any fields I can go to in this area?

Question by commanderzhao   |  last reply


Is it possible to make a magnetic field strong enough to prevent a gun from firing?

Is it possible to make a magnetic field strong enough to prevent a gun from firing, stoppng the moving parts from moving? If so is it possible to make it directional?

Question by Kyndig   |  last reply



Is it possible to make the magnets lose it magnetic field permanently? Answered

I know magnets can lose its magnetic properties if exposed to heat, but is there a way to make the magnets permanently lose its magnetic fields?

Question by Plasmana   |  last reply



Hitting Enter in PM Subject field sends msg

. Subject says it all. Can you just reject Enters in the Subject fld?

Topic by NachoMahma   |  last reply


how to make a circiut that senses and responds to megnetic fields? Answered

I need to make a circuit to power an overunity generater

Question by nerd7473   |  last reply


iRobot Create Submission: Automatic Field Chalker/Painter

Hello fellow Instructablites,As both an athlete and innovator, I am constantly looking for fun, easy, and creative ways to circumvent mundane tasks or activities. One specific task I've noticed many a time is chalking or spray painting line dimensions onto a playing field or court. For some sports, such as baseball and driveway basketball, the playing fields are chalked instead of painted. The lines are time and again washed away by a rain storm and it must be done over. With soccer fields, the painting must be done once a season, plus the second coat for playoffs. Basketball courts must be taped once a season as well.What compels me so much to create such a bot is the degree of simplicity that can be achieved for these tasks. There is so much complexity in laying out a correct set of lines and arcs. From circular three point arcs to proper dimensions of a volleyball court, there is plenty of room for human mistakes. A fully automatic Roomba would be able to both speed up and eliminate incorrect, and potentially gerrymandered, field lines. They will be pre-programmed on the bot and selected for what particular field it is designated to line.I am convinced that all of these types of tasks can be implemented into an "iRobot Create" to lessen the burden and hassle of the aforementioned activities. My brother Steve and I have developed this idea and fully believe it can be implemented well within out intellectual boundaries.After reading some of the comments we've received, we are now taking into consideration some new ideas. In-route Calibration. We aim to implement an accelerometer to keep the dead reckoning honest. Chalking repository. Instead of heaving all the chalk around in one huge battery draining load, we are considering using chalk/paint stations to refill the coating supply. Hopefully this will keep power usage at a minimum. Tank treads. These will probably enhance the fielder chalker/painter in every way, since it will be used outdoors.Thank you for taking the time to read our entry!Nick and Steve

Topic by technick29   |  last reply