Calculating Electro-Magnet Holding Force

  • Thread starter Thread starter kosoniscs
  • Start date Start date
  • Tags Tags
    Calculation
Click For Summary

Discussion Overview

The discussion revolves around calculating the holding force of an electric magnet, specifically in the context of lifting a weight of 1 kg. Participants explore the relationship between various parameters such as current, coil turns, and material properties, as well as the equations that can be used to estimate the attractive force.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant seeks assistance in calculating the attractive force of an electric magnet, noting the dependence on current, number of wires, and the quality of the core material.
  • Another participant mentions that the magnetic force is related to the gradient of the magnetic field and introduces the concept of magnetic moment and energy changes due to air gaps between magnets.
  • A third participant provides a formula for estimating holding force, specifically F=0.577B^2 A, where B is the flux density and A is the area of the pole face.

Areas of Agreement / Disagreement

Participants present various approaches and equations for calculating the holding force, but there is no consensus on a single method or formula. The discussion remains open with multiple viewpoints and techniques being explored.

Contextual Notes

The discussion includes assumptions about the parameters involved in the calculations, such as the nature of the magnetic field and the specific conditions under which the formulas apply. There are also references to external resources that may not be universally accessible.

kosoniscs
Messages
3
Reaction score
0
How can I calculate a electric-magnet? I mean, I want to built a electric-magnet to raise for example 1kg. I know that the atractive force depends on the current and the number of wires in the coil, as well the quality of the steel in the middle of the coil. But I don't know how can I associate this parameters to an attractive force like 10 Newonts.
Can anybody help?
 
Engineering news on Phys.org
Welcome to Physics Forums, kosoniscs.

Please be sure to read our guidelines ... we ask you to not make double posts.
 
The magnetic force depends on the gradient of the magnetic field:

[tex]F=m\frac{dB}{dx}[/tex]

(For simplicity I use only one dimension),
here m is a magnetic moment. The magnetic moment itself may be proportional to the external magnetic field strength.
The magnetic field far from the magnet may be considered as a field from dipole. It is more difficult to consider the attraction of two attached magnet. One trick may help. Let's make a small air gap between two magnets. If we find out how much energy we can gain by reducing the air gap, we will find out the force, because
[tex]F=dE/dx[/tex]
 
Hi Shyboy...
Could you send me an example?
 
A commonly used equation to estimate holding force is:
[tex]F=0.577B^2 A[/tex]
where B is flux density in kilogauss, and A is the area of a pole face in square inches
http://labcontrol.pqui.utfsm.cl/~wally/Manuals/General/Magnetic/magnetic.htm
 
Last edited by a moderator:

Similar threads

  • · Replies 14 ·
Replies
14
Views
6K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
14
Views
4K
Replies
9
Views
16K
  • · Replies 4 ·
Replies
4
Views
6K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
8
Views
2K
  • · Replies 37 ·
2
Replies
37
Views
5K
Replies
9
Views
6K