# Questions tagged [electromagnet]

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41 views

### Swinging Magnetic Attracted to Batteries [closed]

I have a pendulum in which the Bob is a permanent magnet. The circuit and batteries are hidden inside the base. The problem is that the permanent magnet is attracted to the batteries and slows the ...
71 views

### What is the max voltage I can apply to an electromagnet? [closed]

I have a small Amazon Electromagnet 4 ohms of resistance and wound with 110 feet of 28 AWG lacquered wire. What is the maximum sustained voltage I can put through it?
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32 views

### How to prevent power fluctuations on strong Electromagnetic Lock (2A)?

I'm learning how to control strong Electromagnet Lock using ESP32 microcontroller, but I'm having problems with board freezing at the end of relay activation. So the Lock works, but then the board ...
• 105
58 views

### How can I use a relay and diodes to reverse the polarity to a electromagnet?

I am trying to make a solenoid using a motor, relay, and 12-volt battery. I have everything working, but it only goes one way. I want it to reverse the polarity when the relay is open. Will it work if ...
46 views

### Where does the electricity in electromagnets come from if permanent magnets from generators decrease their magnetic strength?

The question has been puzzling me for some time, I presume electrical power starts from generators, the heat produced by them(generators) cause their magnets to weaken and electromagnets have to be ...
37 views

### Phase shifting 2 waveforms to create a rotating magnetic field

I'm trying to set up a rotating magnetic field with 4 electromagnets coils (2 pairs) arranged around a fluidic cell. I have read that you need to shift the 2 waveforms out of phase by 90 degrees to ...
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1 vote
92 views

### How to improve my son's solar bobble head [closed]

My son has a minecraft solar bobble head (in this case a bobble Steve). Under light it swings a diamond sword this exact one (Puckator Officially Licensed Minecraft Steve Solar Pal https://amzn.eu/d/...
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79 views

### Designing a polarity-reversing electromagnet with energy recovery

I'm looking to design an electromagnet that changes its polarity by the trigger of a pulse signal, by considering the lowest energy drop, I am looking for a sub-system to reserve the energy of the ...
91 views

### Charging and discharging electro-magnet

I was using normal MOSFET to turn a 1.2 H+4.8 Ω electro magnet at 48 V and draw around 10 A. The MOSFETs are getting damaged after a few days. The MOSFET is just used as a switch (no continuous ...
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1 vote
112 views

### Finding the ideal parameters for a homemade electromagnet

I am making an electromagnet and I was watching some videos on designing one. I just have some misunderstanding about power calculations of electromagnets and I have some questions about it. Q1) 1.1) ...
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1 vote
205 views

### How is the holding force of this electromagnet so large?

I am designing a system that uses the magnetic force to fix an object in its place. I plan to connect an I-core to my object and fix it to a fixed C-core by letting a magnetic flux flow through both ...
• 91
85 views

### Electromagnet doesn’t have power [closed]

I have so problem with an electro magnet, I mean it seems a little weak to me. What could I do to improve it’s power? Battery: 3.7V 8800mAh Also, I had the wires in small parts so that’s the reason ...
1 vote
56 views

### Mixing power supplies with inductive loads

I have two unregulated power supply - 24V and 12V. My board consists of digital components and sensors that require 3.3V or 5V. All that electronics is resposible for electromagnets or DC brush motors ...
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56 views

### Magnetic Field Produced By Electromagnet Perpendicular Winding

If I wound wire like a cylinder (blue) and then continued in a perpendicular direction like a toroid (yellow), what would the magnetic field look like?
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1 vote
65 views

### Wrong orientation of a diode destroy a circuit (Schematic included)

I get 24V from the barrel jack. The electromagnet is controlled using PWM. Here, I made a mistake and the diode direction is reversed. (The diode is placed to protect from back EMF.) When I plugged ...
• 117
171 views

### Do superconducting electromagnets require less energy than resistive type electromagnets to create the same strength of magnetic field?

Do we require less power in the superconducting (cryogenically Cooled) electromagnet than the resistive type electromagnet? If you have any figures or the voltage and current graph for both magnets, ...
80 views

### How do I create an AC electromagnet for a particular type of field generator?

I’m trying to generate a special sort of field in a spherical spinning iron core using two orthogonally oriented coils. One single-layer coil of 18 AWG magnet wire is wrapped directly onto most of the ...
106 views

### How can I control five hundred 250 mA electromagnets with shift registers and MOSFETs at the same time?

At the moment I control 16 electromagnets. I will later daisy chain the shift register control boards to control 500 electromagnets 250 mA each at 24 V (could be 12 V) with shift registers and MOSFETs ...
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244 views

### H-Bridge Circuit w/ Inductor Demagnetization

I'm building an H-bridge circuit designed to send a pulse through an electromagnet, and then rapidly collapse the field of the electromagnet coil as soon as the transistors switch off. Minimizing the ...
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1 vote
121 views

### Can a solenoid be made of copper strips?

Could a coil of copper strips instead of copper wires be used as a solenoid? Are there any real world examples of making solenoids out of strips of copper?
121 views

### How do we maximize core and winding losses in an electromagnet (and calculate them) for variable DC input?

Bigger Picture: Imagine a magnet approaching the solenoid with some initial constant velocity on $v_0$ on x axis. The approaching magnet will induce an EMF and induced current in solenoid. We want ...
122 views

### Grid of electromagnets influencing eachother

I'm trying to create a grid of electromagnets to move around some iron filings on a piece of paper. I made a prototype with a 3x3 grid made of some nails and enamaled wire, and but I've found that ...
120 views

### 12 V, 7 Ah equivalent transformer

I am trying to power a maglock. The specs say its current draw is 12 V, 500 mA. It works fine when powered by a 12V battery (Mighty Max ML7-12). However, it doesn't work when powered by a 12 VDC, 2A ...
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1 vote
135 views

### How powerful would be a Bitter configuration electromagnet made of aluminium foil?

The specs: The electromagnet has 7,2 cm of height, 1 cm of radius. A hole with 2,5 mm of radius in the middle. An aluminium foil has 0,024 mm of height so I assumed the insulator layer has the same ...
• 370
1 vote
58 views

### Can laser-induced graphene wires produce electromagnetic fields if a current is passed through them?

For those who don't know, laser-induced graphene (LIG) is a porous type of graphene that appears after exposing certain types of carbon-based materials with a laser. In this video, they made LIG on ...
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1 vote
175 views

### Filtering peaks of a H-bridge driving an electromagnet?

I'm driving an electromagnet (56.5Ω, 59mH) with an H-bridge composed by N-Type MOSFETs (SiHFR120) and half-bridge drivers (2EDL05I06PF). VDD is 80V. Everything works fine excepting the huge current ...
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156 views

### Proper way to switch 80 VDC for continous high current operation?

I'm designing a circuit to change current direction for an electromagnet (57 Ω, 76.2 mH) which I drive with 80 V. I have been using an H-bridge but due to the long on-state period (several seconds), ...
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240 views

### Control 12V relay by using Arduino [closed]

I have an Arduino Mega, 12V relay module, and 12V external power supply. I want to control relay state (on/off) by using Arduino I/O pins (5V). Is it good idea to use following simple diagram? There ...
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1 vote
584 views

### Snubber circuit for electromagnet

I have run into the same problem described here and here, when I added diode to electromagnet. Basically, the magnet still holds with about 20kg force several minutes after removing power. The ...
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7k views

### How do I build an electromagnet?

I want to make an electromagnet that can lift a paper clip off of the ground from a short distance (probably 7 to 8 inches). I naively thought of making an electromagnet as a simple task (because of ...
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35 views

### Briefly Drive Permanent Electromagnet [duplicate]

I need to drive a 12VDC/1.2A permanent Electromagnet for 2 seconds (to release object). Will the attached circuit be able to do that or do I need something else? Thank you https://i.sstatic.net/Npy3w....
113 views

### Possibility of achieving magnetic levitation(Arduino) with just one solenoid and a ring magnet?

I am currently working on a magnetic levitation project and have been looking into all types of magnetic levitation. One particular video I found around the subject was this: https://www.youtube.com/...
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1 vote
55 views

### What are the components I would need for an electromagnet with the given specifications?

I need to make an electromagnet that exerts at least 5 times its own weight on a ferromagnetic material kept 0.03 m away. I know that: F = [(number of turns × current)2 × magnetic constant(4 × pi × 10-...
109 views

### How do I make an electromagnet that weighs less than 2 kg but can exert a force of at least 420 N

For a project that I am doing currently I will need an electromagnet whose total weight is less than 2kg, but can exert a force of at least 420 N on a ferromagnetic material 0.03 m (3 cm) away from ...
1 vote
227 views

### Is there any effect on efficiency of electromagnet if winding wire cross each other during winding?

While winding a core of the transformer some turns cross other turns. Will this affect the magnetization produced by the core?
240 views

### Determine inductance of large inductor

I asked a similar question before but i am still struggling with this problem. I am trying to measure the inductance of a large (34cm diameter) electromagnetic brake. Important findings to keep in ...
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1 vote
87 views

### Why don't Li-pol accumulators change the polarity of an electromagnet?

I made a simple electromagnet with a screw and a wire. When I supply power to it via 1 AA battery (1.5v) and change + and - contacts it acts differently with other magnets (attracts and repels), but ...
1 vote
476 views

### Determine electromagnet inductance

I am trying to measure the inductance of a large electromagnetic brake (coil diameter 34cm). I used two methods: LCR meter (100Hz because the brake is activated using a rectified 50Hz AC voltage) (...
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1 vote
329 views

### Determining an industrial electromagnet coil's number of turns and wire diameter, etc

I'm a new graduate and fresh hired Electrical Engineer who works in a company building magnetic separators for general industry (including mining, recycling etc.) Normally, we build magnetic ...
123 views

### Preventing a circuit from blowback voltage from an electromagnetic coil [duplicate]

I've connected up the coil of a relay to a transistor, which is in turn connected to an Arduino Nano. The circuit is a timed relay switching circuit. I know that when the current to an electromagnet ...
306 views

### How does this electromagnet control circuit work?

I am reverse engineering an electromagnet control circuit in isolation (I do not have the original controls or wiring diagram). I believe applying 12VDC should trigger the respective magnets, but it ...
3k views

### Ideal dimensions for an electromagnet?

I've been working on a design for an electromagnet. I've exprimented various lengths of core, and figured the height of the windings for 6 different gauges of magnet wire based on the maximum current ...
400 views

### What maximum DC current and maximum voltage can I flow through an inductor?

I have built a toroidal inductor by wrapping an insulated copper wire over a toroidal laminated soft-iron core. The dimensions of core and copper wire are as below: Toroidal core: Inner diameter = 20 ...
66 views

### Problem with Amp Turn calculations for electromagnet

I'm attempting to design an electromagnet, and the equations seemed to produce an nonsensical result. The electromagnet needs to impart 42.75 newtons at 0.0015875 meters. I needed to discern the Amp ...
1 vote
2k views

### Powering an electromagnet

I need an electromagnet so I made one out of an old microwave transformer. (something like this: https://www.instructables.com/Microwave-Electromagnet/) To power this electromagnet I have a DC power ...
91 views

### Turning a transformer into an electromagnet [closed]

I saw in a YouTube video that people turned a transformer into an electromagnet by rearranging the T-shaped metal. When I did the same and plugged it into the AC supply, it gets too hot. I tried ...
2k views

### Ferrite core in electromagnets

I have a small project based around designing a small home-made DC actuator using a small DC electromagnet. My final goal is to generate the strongest magnetic field possible with the minimum amount ...
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1 vote
54 views

### Solenoid Train - Best approach for magnetically guiding an object along a path?

My project is to pull an object along a path with solenoids, by cycling their on/off state. I don't know if ferrous core solenoids pulling steel would be more efficient than pulling a neodymium ...
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