Questions tagged [magnets]
51
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Magnetomotive forces acting on assembly
Apologies if this is the wrong place to pose this question, or if it is poorly formulated, I would appreciate any help, even if that is pointing me to a place where I can learn more about solving ...
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1answer
53 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 ...
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1answer
61 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 ...
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1answer
26 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,...
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22 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 ...
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1answer
22 views
Cheap / Easy source of small amount of ferromagnetic metal [closed]
Hello all I have a magnet in my car to stick my phone to the dashboard. But I changed phone and now my new phone needs some metal stuck to the case in order to attract to the magnet.
I read online ...
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1answer
22 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 ...
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1answer
22 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 ...
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2answers
94 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 ...
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2answers
1k 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 ...
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1answer
107 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 ...
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2answers
117 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 ...
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1answer
65 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 ...
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18 views
Restricted Rotation using electromagnets
I was wondering if I could restrict the rotation of a part over another in one direction alone using an electromagnet but allowing me to have a continuous rotation if forced (maybe by using some ...
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38 views
Is it possible to protect electronics on a cubesat from 100-1000g of acceleration
I am currently researching the feasibility of setting up a coilgun that launches Cubesats for a paper.
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1answer
294 views
Difference between permanent magnet and electromagnet exciter generator in principles wise?
I searched about this, but couldn't find any helpful explanations. All it says is that magnetic field is generated by either permanent magnets or electromagnets. In both cases, how does the exciter ...
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2answers
95 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 ...
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2answers
63 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 ...
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2answers
252 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. ...
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66 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 ...
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67 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 ...
2
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1answer
317 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
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1answer
76 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.
...
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2answers
77 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 ...
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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). ...
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2answers
61 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 ...
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Calculate the relative pulling force as function of size for neodymium magnets
I want to optimise the size and shape of a magnet for a desired pulling force. (Please forgive my limited knowledge of magnetism).
A cylindrical magnet fixed to an object will hold it in place by ...
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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 ...
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2answers
204 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 ...
4
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1answer
267 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 ...
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1answer
226 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.
...
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2answers
97 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-...
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1answer
126 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 ...
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177 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, ...
3
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1answer
260 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 ...
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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 ...
2
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3answers
343 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 ...
4
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1answer
119 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 ...
2
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1answer
61 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 ...
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3answers
6k 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 ...
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2answers
152 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 ...
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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 ...
3
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1answer
193 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 ...
5
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1answer
588 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....
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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 ...
3
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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 ...
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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 ...
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1answer
195 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 ...
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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 ...
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1answer
745 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 ...
