What is Electromagnet: Definition and 371 Discussions

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole, denoting the center of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.
The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.
Electromagnets are widely used as components of other electrical devices, such as motors, generators, electromechanical solenoids, relays, loudspeakers, hard disks, MRI machines, scientific instruments, and magnetic separation equipment. Electromagnets are also employed in industry for picking up and moving heavy iron objects such as scrap iron and steel.

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  1. L

    AC electromagnet questions-I'm smart, but not an engineer-Help

    AC electromagnet questions--I'm smart, but not an engineer--Help! I need an AC electromagnet with these requirements: -17 Hz -square wave -40-60% duty cycle -will run on 60 Hz 110 volt current, and can be plugged into a wall outlet (this one is not an absolute necessity, but it...
  2. K

    Can spinning an electromagnet increase its strength?

    We've heard of the water pipe analogy for electric circuit. It says that the current produces magnetic field and that the "pipe" is irrelevant - only the amp-turns are relevant. So I was wondering, is it possible to increase the amp-turns of a electromagnet by rotating it in the same direction...
  3. 6

    Several electromagnet questions

    Hello guys/gals I have a few questions regarding electromagnets that I'm hoping you can shed some light on for me. I don't know much about physics, magnets, etc. I am a career firefighter that is trying to build something requiring the use of electromagnets. 1. I'm trying to have an...
  4. M

    Question for pulsing electromagnet

    Does it take a certain amount of time for an electromagnet to reach it's full magnetic potential? For example, would a 1 nanosecond pulse of juice be enough to fully magnetize a small lifting electromagnet? Thanks in advance.
  5. T

    Strong electromagnet with a constant field

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  6. S

    Toroidal electromagnet question ( really figuring my proplem out)

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  7. S

    Could Electromagnet Vibration Indicate a Current Limit in the Power Supply?

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  8. R

    How Can I Calculate the Force Produced by an Electromagnet?

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  9. S

    Solving Electromagnet Problem with 24V 24A DC Power Supply

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  10. G

    Electromagnet repulsion increased significantly

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  11. S

    Why is my electromagnet's amperage fluctuating?

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  12. C

    Electromagnet and core permeability

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  13. S

    Protecting Your Power Supply: Using Resistors with Electromagnets

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  14. M

    Formula for the strength of an electromagnet

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  15. C

    Premium electromagnet core material

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  16. M

    Make AC Electromagnet: Tips & Tricks From Experts

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  17. S

    Figuring out the effective pulling distance of an electromagnet

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  18. M

    Electromagnet Winding: 1200 Winds or 600 Winds?

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  19. N

    Electromagnet Questions: Length & Layers

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  20. E

    What is the Difference Between AC and DC Current for Electromagnets?

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  21. W

    Electromagnet Comparison: Does Wire Size Impact Lifting Power?

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  22. P

    How does the shape of an electromagnet pole affect the field produced?

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  23. E

    What is the Magnetic Flux Density of NdFeB and AlNiCo?

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  24. J

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  25. Y

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  26. Nabeshin

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  27. E

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  28. B

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  29. C

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  30. C

    Which Electromagnet Design Works Best?

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  31. K

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  32. M

    How Can I Enhance the Power of a Small Homemade Electromagnet?

    Small Simple Electromagnet...Help Please! hi I'm trying to make a simple small electromagnet using a core from electric drill transformer (I think its called permalloy if I'm not mistaken) which i machined into 17mm long and 2mm diameter. How can i make it powerful enough to produce a force of...
  33. A

    Electromagnet Run From Powr Supply

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  34. P

    Current balances & Electromagnet Induction

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  35. M

    Maximizing Dipole Electromagnet Strength: Coiling Methods Compared

    I am designing an electromagnet and need a strong field strength. I have came across a few different ways to wire the coil and am curious which way produces the strongest dipole electromagnet. The coil is to be wound around a cylindrical steel core. The first way is what I think is the most...
  36. M

    Some General Electromagnet Questions

    Hi, I am fairly new to magnetism and had a few questions regaring the construction of electromagnets. I am trying to build one for a simple application and was hoping for some advice. My application requires a small, preferably short, large-radius cylindrical electromagnet that will act as a...
  37. N

    AC powered Led Zeppelin electromagnet

    I've posted on here a few times concerning the electrical problems I continue to encounter for my video installations. And yet, here's another one. If anyone remembers, I posted a month back or so concerning the use of an audio signal from a home audio receiver to open and close a small...
  38. R

    Solenoid Electromagnet with strong core, low residual magnetism

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  39. M

    Can a homemade electromagnet with aluminum strips withstand 120 volts?

    I'm not too knowledgeable on electricity, but I'm constructing an electromagnet with aluminum strips as the coil and using a 120 volt household current. Proposing to solder an extension cord to the strip coil. 1. When it is plugged into the outlet, will it automatically send juice through the...
  40. C

    Hello, I am currently planning on constructing an electromagnet.

    Hello, I am currently planning on constructing an electromagnet. Its purpose is entirely for entertainment. I was hoping to make two of them that I could attach handles and switches to so they could be used for hanging/climbing underneath some random thing. If possible, it would be useful if...
  41. S

    Designing Electromagnets for a 0.5" Moveable Magnet

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  42. B

    Exploring Electromagnets: Their Uses and Limitations?

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  43. P

    Trying to measure the change in resistance of an electromagnet

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  44. P

    What materials can increase magnetic strength in an electromagnetic coil?

    I realize that soft iron is the most common material for this but I am wondering if there is something that will increase the magnetic strength. Here is what I have. Two electromagnetic coils in series connected by a yoke with a capacitor in parallel (for spark reduction). Cores are soft...
  45. P

    Best core material would be for an electromagnet

    Wondering if anyone can give me a clue as to where I might look for information on what the best core material would be for an electromagnet if price were not an issue. I need as much magnetic strength as possible for between 3-9 volts DC. At between 80-160Hz. Basically this is a solenoid...
  46. L

    Relationship between voltage and the strength of an electromagnet?

    What is the relationship between voltage and the strength of an electromagnet?
  47. J

    Magnets and electromagnet power?

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  48. P

    Design Electromagnet: Pickup 5kg Iron at 300mm Distance

    Homework Statement I want to design Electromagnet in aluminium strip/wire for pickup 5kg iron piece at distance of 300mm and i try many books to calculate the said magnet but failed. I want to know how i calculate above magnet. Please help Homework Equations The Attempt at a Solution
  49. C

    How Can I Dimension an Electromagnet for Maximum Strength?

    Hi, I like to research the possibility to build an electromagnet that is quit big and has a lot of strength. As I really don't know much about magnetism, I don't see how to start with this. Anyone that please can help me with some formulas? I like to make a sort of excel or MATLAB...
  50. O

    Why Do We Use Weak Electromagnets in Common DC Motors?

    If a toy electromagent holds 200 lbs on 2 d cells is that overunity? If not could someone explain it without just stating the 2nd law of thermal dynamics. Also if anyone knows the push against and armature in an electric motor compared to the pull of an electromagnet built for lifting...
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