Electromagnet Definition and 372 Threads

Homework Statement Need to build an electromagnet. Want to build one to work on 12v 7Ah battery with a switch. Needs to be on for up to a minute. Gets pretty hot. Any ideas what components can be wired into circuit and how to control current to retain magnetic field strength but reduce the heat?

Hello every one I’m a newbie to electrical stuff (I do have basic knowledge) so please be patient with me, please help me! :frown: So, coming to the details of my diy project I’m trying to vibrate a metal string with an electromagnet. so, after an ample amount of research I’ve made the...

Homework Statement A small but very powerful bar magnet falls from rest under gravity through the center of a horizontal ring of conducting wire, as shown in the figure below (on the left). The speed-versus-time graph, in arbitrary units, of the magnet will correspond most closely to which of...

I want to make an electromagnet that can carry me or buy one. I weigh 128 pounds (58kg) and I found an electromagnet with a pull force of 178 pounds (80kg). https://www.amazon.com/dp/B01EWHSF3K/?tag=pfamazon01-20 Can I attach any 12v source to power it or does it need a specific amperage. And...

I regret I know nothing about subject but wonder if anyone could advise where I could obtain a device (including magnets) which will change the polarity of two electro magnets from once per second to hundreds of times per second?

I am new to this site and I am not a physics / engineering professional. Please excuse me if I only have a layman's understanding. I have been trying to make a device to sense a 2 foot long by 2 inch diameter rod at an 8 foot distance (all steel, all ferrious). to be detected. I have tried home...

I was wondering if diamagnetism can be created electrically or does the material have to be diamagnetic in nature?

Hello! Recently I was going through some old exams and upon encountering this problem (which seemed pretty easy) I got stuck. Exams at my university are composed of individual tasks, each having three subquestions with four plausible answers respectively. Solution sheet gives results only, so...

I've searched high and low and come up with a lot of "maybes" and "could be's" and "try this" to a problem which I feel should have at least a few example calculations floating around the internet. The questions is trivial but it seems like the solution is fairly complicated. I'm not looking for...

I have these two very large (ferrous core) coils, They are basically identical, each 200mm long and have a diameter of 100mm. The core is medium grade steel One coil is receiving an input of 8V(peak-to-peak) @ 4 MHz from the function generator. The second coil is placed 1m away, and is...

I am trying to calculate the forces (in Newtons) between a permanent magnet, and an electromagnet. All I can find is interactions between permanent magnets, electromagnets, but never both and it is getting really confusing for me to do the calculations. So basically, if I have a permanent...

I wired a quick weak electromagnet. How come when I put a small permanent magnet close to it, both sides of the permanent magnet (north and south) are attracted to the same side of the electromagnet?

If I wrap a coil around a bar magnet and shoot current through the coil so that the magnetic field of the electromagnet is at the same polarity of the bar magnet will I have amplified the magnetic field of the bar magnet maintaining the same magnetic shape but bigger/stronger?

Hello everyone, So for a personal project I want to calculate the force necessary for a solenoid (electromagnetic coil) to keep a permanent magnet triangle locked diagonally up and down at the same time so that it does not move in any direction. I need to know the values for coil thickness...

Hi, My name is Kendall. After seeing the Back to the Future again, I have been once again fascinated by the hoverboards, as I'm sure many others are also guilty of. A couple hours of research into magnetism later, and I'm still stuck. I have little to no experience with magnetism, but I figure...

I need to make an electromagnet that would generate a force to lift 1/2-1kg, and would use a current of 100mA, if not possible 200mA would be fine as an Arduino supplies a maximum of 500mA and 5V, and if 1kg is not possible then 1/2Kg would be fine, please help me in my calculation. and which...

Mentor note: Post moved from Educators and Teaching section Hi I would appreciate some clarity regarding using electromagnets as generators? Why are they used instead of permanent magnets specifically given that electrical power is needed? What is the difference between the power in and power...

I have an electromagnet device that I am designing and need a bit of help from some of the brilliant people on this site. Here's the problem: I have a disk attached to the end of a shaft and the shaft/disk assembly can move radially (via a spring loaded mechanism). This shaft/disk fits...

I need help find a electromagnet suitable for this http://imgur.com/a/vkm4T Each electromagnet (the 3 in the center) needs a repelling force of about 20 to 40lbf. I stupidly bought these from amazon http://a.co/aSftIat. Its a holding electromagnet so the N and S poles are essentially on the same...

Hello, i need a small electro magnet with it's dimension not bigger than 8 millimetre (0,31 inch) in diameter with a length under 10 millimetre (0,39 inch). I want it to be as powerful as possible, where do i find such magnets? And how should i make my own? How powerful is it possible to make...

what we have to work with is a portable generator ~240vac ~3500watts then to a step up transformer so output ~540vac. then a full wave bridge rectifier to make the DC thought is we have a semi truck rim (will get the diameter/size soon) (due to this will get slammed around and banged into...

I'm trying to build a large electromagnet. It's actually 3 letters, as large as I can get them to be and still work. It's for a scavenger hunt. My dad's an electrician and he says he can't figure out how to make it work, I'm hoping someone has some input. The requirements are that it has to...

Electromagnets heat up quickly...shouldn't heat destroy its magnetic properties?

Hello. I am trying to design an EI-core electromagnet (think two c-shaped cores with their gaps abutting). The coils would go on the top and bottom legs of the E (legs B and C in my sketch). There is a sketchbelow and you can find one here...

Hi, I want to repel a permanent Neo magnet using an electromagnet which i want to build. The distance from which it should repel is about 2 inches and to a height of 1 inch. So what would be the ideal gauge of copper wire and the number of turns on the MS rod as core, if i supply 12v DC through...

When a supercooled type two superconductor is subjected to a static magnetic field, the superconductor pins to the flux of the field (the mixed-state meissner effect is apparent). What happens if it is subjected to a continuously changing magnetic field, assuming the superconductivity takes...

Hello guys. I am new member of this forum and I am looking for some guidance on a certain project. Now, the reason I am posting is that I need your help with a project I am currently just starting and of which unfortunately I have little details figured out as well, so please bear with me if you...

In my adventures through my attempt at a home laboratory i decided i would try to play with electricity a bit more. I took an iron cylinder 1 inch diameter 6 inch length and wrapped about 4 meters of 1mm copper wire around it with a small length hanging off each side. To my understanding...

Hello! I have been wanting to make a big ol' electromagnet for a while now. I thought instead of just going out to buy random stuff perhaps I should explore the science first. My plan was to get some rebar, a car battery, and some insulated wire to wrap around the rebar to creat en...

My goal is to make an electromagnet that delivers 100mT magnetic field on one end of the iron. The iron core has a diameter 2.0mm and length 0.1m. I am using a copper wire that can carry 2.3A of current, and I am using a DC power supply. I have been able to create a 100mT magnetic field on the...

Homework Statement Homework Equations ##\oint_{C} Bd\ell = \mu I_{enc}, B_{normal}## continuous across boundary, ##H_{parallel}## continuous across boundary The Attempt at a Solution $$\oint_{C} Bd\ell = \mu I_{enc} \rightarrow B = \frac{\mu NI}{2\pi r}$$ Any help much appreciated. How...

Hi again and thank you again for the help If I have two magnetic fields, one permanent ring magnet B2 free floating on a fixed electromagnetic coil B1 and the field are perpendicular 90 deg to each other will the free floating permanent ring magnet feel a strong magnetic torque and rotate...

Hey, I'm lightly studying 'Generating' as a topic in my Physics curriculum. I have just been introduced to an AC Generator, an Alternator, and I have a simple question: Is the armature in an alternator an electromagnet? From my understanding, there is a U-Shaped length of wire(s) which...

Following is a conversation that was started by a fellow tinkering with a MOT which can be very dangerous but to his credit he DID remove the deadly high voltage winding(at least he said he did). It belongs in a thread so I'm moving it here ------------------------------------------...

I am trying to create a solenoid with a high flux density, but I need the specifications (wire gauge, current applied, etc). The diameter of the core would be preferable around 15mm. The length can be pretty much anything reasonable. I need this for a project that requires a strong repulsive...

Hi guys, I'm using an electromagnet to detect the presence of a steel door through analog pins on an Arduino. This works great if the magnet itself isn't under power, but once I'm running 12 volts through it, the sensitivity of the readings fall apart. I'm using a resistor based voltage divider...

I want to make an electromagnet but it should Produce magnetic flux which changes with time. What material wire would be the best to make make windings?

For our physics class we have to design an experiment investigating the factors affecting an electromagnet's field strength. I have decided to investigate the number of coils in the wire. My only problem is, I'm not sure how to measure the field strength. Our teacher gave us two things which we...

The title is explanatory. I know that an iron core yields a stronger electromagnet. What if you have an electromagnet with an extremely tiny air coil relative to its volume? Does the small air coil diameter effect the electromagnet?

Does anybody happen to know the strength of the electroMAGNETic lenses of a scanning electron microscope? I was thinking of using solenoid coils, which would be enough if I am willing to increase the focal distance, but the lenses on SEM's seem far larger.

I want to design electromagnet for my project. I want to know which formulas are used while designing electromagnets and methodology if we know repulsive force we require at a distance of 25mm from one end of electromagnet.

I am making a sign out at my farm. I am making everything myself and have come up with an idea on getting the letters to stick to the front of the sign with magnets. I just have plastic letters with magnets glued to the back and they just stick on the front of the sign that has a galvanized...

I am an eleventh grade student currently in AP Physics C. My teacher did a demonstration with an electromagnet where he drew AC current from the wall to shoot a conductive ring. I was wondering where i could find the blueprint for such a device, or perhaps receive some guidance on how many coils...

Hi, I am investigating the possibility of using 2 oppositely polarised electromagnetics to locate 2 moving bodies into the correct position as they move towards each other and would appreciate some thoughts on the feasibility of the solution and ways it might be improved. I am proposing using...

Homework Statement Two identical long wires of radius a = 2.90 mm are parallel and carry identical currents of i = 5.00 A in opposite directions. Their center-to-center separation is W = 17.0 cm. Neglect the flux within the wires but consider the flux in the region between the wires. What is...

I found this formula to approximate the inductance of a coil of wire. But what if a solenoid were composed of N separate loops, where each loop of the solenoid is connected to its own battery? That is, what if the solenoid had the same number of loops and the same geometry, except that each loop...

Hello Everyone: Take a look at the following diagram Assuming the coil build above. How would you determine the force pushing-pulling the Neodymium Magnet in the center of the plastic pipe. I know the number of turns, length, amperage are in effect.

Hello, So I am working on a project that requires the movement of iron nanoparticles (let's assume 25nm in diameter, and let's assume the sphere is uniform and pure iron) through a (non-magnetic) gel using an externally applied magnetic field. Let's assume the total distance I want to move the...

When you switch on an electromagnet (who's north pole is pointing to the left), is it the same thing as if you had pushed a permanent magnet to the left? Or to the right? I believe it's to the left. But apparently my textbook thinks it's to the right. Who's correct? Why I'm asking:I've attached...

I'm working on a project where i need to control an electromagnet but I'm not sure how to do it. I tried using a npn but the current passing through the magnet is just to small, should I use a mosfet instead. The specifications for my project say that they will provide us with 9 volts and a...