Questions tagged [magnets]

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17
votes
1answer
792 views

Can we change steel properties by application of magnetic field while quenching?

Austenite is non magnetic while $\alpha$-ferrite and pearlite are magnetic. (Magnetic properties of pearlite vary as a function of carbon content) If a strong magnetic field is applied in a ...
12
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3answers
7k views

Can a magnetic lock be negated or overcome by a stronger electromagnet?

Magnetic locks seem to be fairly common on the doors of modern buildings, but I question their reliability when compared to a traditional, mechanical lock. I realize that the strength that it would ...
9
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2answers
2k views

What causes friction in magnetic bearings?

Magnetic bearings work by levitating a rotating shaft so that it is not in contact with its supports. This greatly reduces the friction of the system. In all of the literature that I have seen on ...
8
votes
1answer
198 views

Best way to send a signal in a very low frequency (250Hz)?

I am a programmer facing an electronic question, so I thought here is the place to ask! I have a magnetic field sensor which provides me with magnetic field values (XYZ axis) 250 times a second. An ...
7
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2answers
187 views

Under what circumstances would one need or not need an electronic brake for a permanent magnet motor?

My company was asked to design a custom product several years ago. The original requester never bought it, but we've sold several a year through distribution. It's been a small side-line for a while, ...
5
votes
1answer
4k views

What grade of Neodymium magnets are commonly used in hard drives?

I want to buy some magnets, but the ones that I have found on online shops are mostly grade N38. They are pretty cheap, but they need to be as strong as the ones found in a hard drives. I am afraid ...
5
votes
1answer
604 views

Calculating Anisotropic Thermal Conductivity for two Materials

I've been working with SC magnet quench simulations. The conductor is made from NbTi in a Cu channel with a 5:1 ratio of Cu:NbTi. Opera3d has a quench program with an example that I began working from....
4
votes
1answer
131 views

How to 'smooth/flatten' the surface of a disturbed liquid without contacting it?

I would like to essentially flatten or smooth the surface of a viscous liquid after dropping an object into it, without actually touching the liquid. For example, if I drop a rock into a tub of oil, I ...
4
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1answer
241 views

Magnetic levitation [closed]

I am currently considering turning my fascination with magnets into a diy activity. How feasible is it for a hobbyist to construct a working model of a maglev device? I'm looking to build something ...
4
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1answer
138 views

3D Representation of Magnetic Field Lines

There are several tools available for monitoring electrical metrics (voltage, current, resistance, frequency). I have recently acquired all that I need for these studies. What tools are available for ...
4
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1answer
126 views

Can a Foucault's current brake be used on the rails themselves to brake trains?

Your typical Foucault's current brakes operate on a disk, which is placed in an electromagnetic field in order to transform kinetic energy into heat without friction. The problem is that the disk ...
4
votes
1answer
282 views

Magnetic decoupling torque

I have a system consisting of 4 magnets rotating at speeds between 200 and 6,000rpm, which are facing 4 other magnets with a 0.5mm gap between the two sets. The set-up looks like this: Both sets of ...
3
votes
1answer
2k views

Do magnetic fields applied to a fuel line have an effect on heat output?

I am doing my final year engineering project on Magnetic Field Assisted Combustion and was curious to see what people thought about it. Companies sell rare earth magnetic arrangements to be attached ...
3
votes
2answers
209 views

How to split mercury with a magnetic force?

Do you think, one could split a mercury drop into two drops with the magnetic force? Mercury is a liquid metal, hence if I put a current through it, it will become a electromagnet (a wire with a ...
3
votes
1answer
272 views

How does a Levitron work?

I just watched this video: https://www.facebook.com/HigherPerspective/videos/1162007547164896/ I don't understand what I see. If the spinner's magnetic, the bowl is made of iron and that the wood ...
3
votes
1answer
195 views

How is the attractive force between two magnets changed when they are separated by non-metalic solids?

I recently encountered the following practical problem. We have a system of several layers: a neodymium magnet; a disc, dimensions and grade to be determined 1 mm of 925 sterling silver; we can ...
2
votes
3answers
372 views

How to form a seal around a sharp moving blade?

I have a setup where I want to move a knife like blade through a body of liquid inside a container and I want to control the blade from outside the container. Apart from using magnets to move the ...
2
votes
2answers
309 views

Is martensitic steel 455 magnetic?

According to wikipedia there are 3 types of steel based on the crystal structure: austenitic, ferritic and martensitic. Austenitic steels are non-magnetic where 300 series stainless steels belong to. ...
2
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2answers
2k views

How do I add magnets to the mechanism of my exercise bike?

I have an exercise bike that works by a (I'm assuming solid iron) flywheel and a 'horseshoe' of magnets that are moved in and out to set the difficulty. I have attached an image of the same design ...
2
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2answers
64 views

How do I separate these powerful magnets from their base plates?

Old hard drives are my favourite source of super-powered fridge magnets. I have a bunch of them holding up countless childrens' drawings. But the magnets themselves are stuck to base plates of various ...
2
votes
1answer
341 views

Can a neutrally bouyant helium balloon be suspended in air using magnet entrapment?

The above picture is a basic concept of how a levitron toy works. Could the top floating peace stay entrapped in the magnetic field without having to spin if the edges of the balloon keep the top ...
2
votes
1answer
87 views

Generating practical power without an iron core, but with high RPM

Here's what I'm proposing - a small turbine directly coupled to a permanent magnet that's spinning at, say, 150k RPM. The magnet is enclosed one or several wire loops parallel to the axis of rotation. ...
2
votes
1answer
65 views

How to calculate the maximum spacing between Hemholtz coils?

I would like to design a long, uniform magnetic field using Hemholtz coils but am not sure how far I can separate them before the field lines diverge and become two loops that go around each coil ...
2
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0answers
37 views

Magnetic Force - Point of Load

I am using a Magnet like this in an assembly and I am trying to calculate the torque in point P2 (see picture below) resulting from the attraction force F between my magnet and the steel part. As I ...
2
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0answers
133 views

Using magnetic field readings for linear gesture recognition

I am thinking about using a permanent magnet as an input device for my smartphone. I have been reading some papers about it, but I really want to understand how things work. Using the integrated ...
2
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0answers
49 views

Could magnets at the RHIC be damaged like the ones at the LHC were in 2008?

In 2008, an electrical fault led to a freaky magnetic quench at the Large Hadron Collider, which in turn released a lot of helium, damaging dozens of superconducting magnets in the process and setting ...
1
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2answers
135 views

Can you use an electromagnet to break the connection of a permanent magnet?

At first, I had a particular goal, but I'm starting to doubt feasibility which has led me here. Original Goal: Create a small (3in²) electromagnet with 100% duty cycle capable of holding at least ...
1
vote
2answers
68 views

Could a magnetic audio tape recorder/player be made using a vibrating permanent magnet?

Cassette tape players use a read head where the magnetic field from the tape is directed through an induction coil. The induced current in the coil is then amplified and sent to the speakers. Now I'm ...
1
vote
1answer
254 views

why is the outside of an electromagnet not magnetic?

On the electromagnet setup pictured below, only the core part is magnetic (when powered, it attracts a piece of steel) but not the 2 "wings" outside that are supposed to channel the magnetic flux. ...
1
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1answer
36 views

How does the magnet sheet sliding metal mechanism work?

I was watching this video - at 10:23 mark where the person was using a hook mechanism for sliding the metal sheets together and noted that sometimes the hook would get caught on a bad angle. To solve ...
1
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3answers
76 views

What Goes Into Making a Variable Field Magnetic Motor?

(I feel it is necessary to mention that I am not an electrical or mechanical engineer; I just like to build fun things.) I've already got a good explanation of the concepts involved in a variable ...
1
vote
1answer
28 views

Can you make the magnets rotate inside the coils of Brushless motor?

I know that current brushless motors, have a non rotating core made of copper coils, with permanent magnets on the outside rotating around it, and eventually connected to a shaft. But i was wondering,...
1
vote
1answer
23 views

Demagnetize neodymium permanent magnets at < 60 degrees C

I have 10 cylindrical neodymium permanent magnets about 5mm in diameter, 5 mm long, embedded in a thermoplastic polymer. I want to demagnetize them without removing them, or heating them above 60 C ...
1
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1answer
85 views

Can magnetic stripes be read wirelessly with lasers or other technologies?

I know that magnetic stripes used in credit cards and audio tapes are typically read by a magnetic reader head. But is it theoretically possible for the stripe to be read by a laser in a similar ...
1
vote
3answers
5k views

Effect of magnetic field on electronic components

Are electronic components like diodes,transistors, micro-controllers, microprocessors, wireless transceivers etc are damaged by strong static or dynamic magnetic fields? If yes, at what strength the ...
1
vote
1answer
66 views

Making a strong electro magnet

I am looking into making a strong electro magnet. I want it to be able to hold around 100 pounds of weight or more. Would a magnetic core like this work at all? I'm planning on wrapping wire around ...
1
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0answers
26 views

Practical estimation of magnetic force

I'm trying to estimate the magnetic force which develops on a truss-like ferromagnetic structure (I want to estimate the motion of the object) in a uniform magnetic field, and I came to realize that I ...
1
vote
2answers
111 views

How to design a magnet to handle a known force?

There is a metallical structure. I can estimate how much steel are in it. I would like to know how tall/strong a magnet should be to maintain a certain object to the metallical structure. The object ...
1
vote
2answers
106 views

Compensating for a magnet in a device with a magnetometer

I'm working on a device that relies on data from a magnetometer. Unfortunately, the device also needs to have a fairly powerful magnet on it. Given that the design is fairly flexible, and within ...
1
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0answers
67 views

Does the Hyperloop One suspension require constant current through copper windings?

As a follow-up to How does the pressurized suspension of the Hyperloop not affect the tube pressure?, I believe (though I can't find where I read it now) that the Virgin Hyperloop One implementation ...
1
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0answers
69 views

Could we use NE 555 Timer for industrial magnetic proximity switching circuit?

I actually need a magnetic proximity switching circuit such that In the case of water in fuel sensor, whenever the water level in water in fuel sensor increases the magnetic float shall move and come ...
1
vote
0answers
76 views

How can I calculate field strength of a Neodymium Ring magnet at an angle?

How can I calculate field strength of a Neodymium Ring magnet at an angle? I have a Neodymium Ring magnet, and I rotate the magnet around an axis perpendicular to the poles. (Not continuous rotation). ...
0
votes
2answers
78 views

Magnetic Entrapped Storage at 0 gravity

I understand this is a multifaceted question and I apologize . All of it is relevant to be understood. On Earth Fly wheel storage devices are used as an alternative to batteries. Even with magnetic ...
0
votes
1answer
56 views

Rotating a lead screw with a moving magnet

Is it possible to introduce torque on a lead screw (with no magnets attached to it) with a moving magnet that can only move parallels to the screw? (the lead screw is ferromagnetic) Something like ...
0
votes
1answer
24 views

Designing a "ratcheting" spinning wheel with ferrous metal bits

I'm trying to design a freely spinning wheel that will "lock" into a few different configurations. I'm planning on placing a rare earth magnet near a certain point on the wheel, and inserting bits of ...
0
votes
1answer
30 views

Use magnetic levitation to lift a carousel capable of turning 9000lbs [closed]

Allow me to describe my current situation. I have a 18 ft (5.486 m) carousel that is assembled using steel beams that are bent into two circles, an outer and an inner. And there are steel spokes ...
0
votes
1answer
118 views

Looking for a compression spring alternative with 10x lifespan

I'm working on a project where 100k spring cycles is gonna last a few months Any recommendations on an alternative? I considered magnets but their sprigabilty isn't great (also, will they get ...
0
votes
2answers
100 views

Is there a device like this? [closed]

I would like to get my hands on a mechanically-set timer (wind up is fine, so that it's self-powered) which sends a small electrical pulse to a mag-lock once the timer goes off, thus causing the mag-...
0
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2answers
153 views

Live motion simulation with respect to electromagnetic field software

Totally numb question from non-engineer, so sorry about that. For my little home project I need to create a matrix of solenoids, so I need some kind of simulation. I wish to be able to create metal ...
0
votes
1answer
45 views

How this synchronous motor works and how to modify them?

I have the following synchronous motor ripped out from an old range hood in my kitchen. I used new electrician tape to cover up the coils that should form the electromagnet--the old cover is too oily....