How to wire a STRONG electromagnet

In summary,- The magnetic force is not strong enough- There is a huge range of 'Ferrite' materials so you would need to specify what its permeability is.- You may be better to use a piece of steel for your purpose - readily available in many shapes and sizes and easy to cut and shape.- It all depends on amps, turns, and core material. Swap your ferrite core for a steel bolt and see how that works out.
  • #1
Undacuva
8
0
Hi everyone,
I have a 12mm long hard ferrite core that I want to use as an electromagnet. I have wound it with 0.8mm copper as tightly as I can by hand, in a single layer, but the field is not strong enough. I have placed another coil over that first coil, and then a third coil, each in parallel - branching before the core, and then re-connecting afterward - wound concentrically in the same direction, to increase the number of windings. I'm still not getting the magnetic force I need. The electrical source is a car battery with 490 cold cranking amps (CCA) -- There is no overheating now that I have 3 branches.

Am I doing something wrong? Is there a winding method that will work better? Do I need higher voltage or just higher current?
 
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  • #2
http://easycalculation.com/engineering/electrical/solenoid-force.php
http://www.ehow.com/how_5969962_calculate-force-electromagnet.html
http://www.byronacademy.org/knowledge-center/view/calculatiing-emf-in-solenoid/
http://www.electronics-tutorials.ws/electromagnetism/electromagnets.html
http://en.wikipedia.org/wiki/Permeability_(electromagnetism )

The mains factors are:

- the intensity of the current in the wires
- the number of turns
- the length
- the permeability of the material
- and also what your objective is: why is the field "not strong enough", how do you expect?

You need to check all of them.
 
Last edited by a moderator:
  • #3
Undacuva said:
Hi everyone,
I have a 12mm long hard ferrite core that I want to use as an electromagnet. I have wound it with 0.8mm copper as tightly as I can by hand, in a single layer, but the field is not strong enough. I have placed another coil over that first coil, and then a third coil, each in parallel - branching before the core, and then re-connecting afterward - wound concentrically in the same direction, to increase the number of windings. I'm still not getting the magnetic force I need. The electrical source is a car battery with 490 cold cranking amps (CCA) -- There is no overheating now that I have 3 branches.

Am I doing something wrong? Is there a winding method that will work better? Do I need higher voltage or just higher current?

There is a huge range of 'Ferrite' materials so you would need to specify what its permeability is. The original application it was used for would indicate what its permeability is likely to be. Basically, ferrets that are used for high frequency RF work have low permeability in order to have low loss in the material.
You may be better to use a piece of steel for your purpose - readily available in many shapes and sizes and easy to cut and shape.
 
  • #4
It would be interesting to know if the "strength" increased as expected when you added the extra windings? eg did it double then treble?
 
  • #5
Undacuva said:
Am I doing something wrong? Is there a winding method that will work better? Do I need higher voltage or just higher current?
It all depends on amps, turns, and core material. Swap your ferrite core for a steel bolt and see how that works out.

EDITED
You have your 3 layers electrically connected in parallel? For a stronger magnet, either add more layers still, or replace what you have with thicker wire that can carry more current from your battery. Just watch that it doesn't overheat, though.

Good luck with your experimenting.
 
  • #6
Hi everyone,
Thanks for the responses. It seems that no-one has any issues with my winding method. What about increasing the voltage? Is there any use in that? Or could I sacrifice voltage for higher current?
 
  • #7
What matters directly is the current. To increase the current, you can either decrease the resistance or increase the voltage (Ohm's Law).
 
  • #8
but how much stronger do you want? I mean if it needs to be 10x stronger you are looking at needing 120V which would be dangerous.

Did it get _any_ stronger when you added extra windings?
 
  • #9
Undacuva said:
Hi everyone,
Thanks for the responses. It seems that no-one has any issues with my winding method. What about increasing the voltage? Is there any use in that? Or could I sacrifice voltage for higher current?

Unless you attend to the core material, you may not get anywhere. The core could have a very low permeability or you could be saturating it if you increase Ampere-Turns ad infinitum.

The Volts - Current compromise is always relevant. I think it will depend upon the power supply you have as to what is the best combination.
 

1. How do I choose the right wire for a strong electromagnet?

The wire used for an electromagnet should have a low resistance and be able to carry a high current. This is typically achieved with copper wire, as it has a low resistance and can handle high currents without overheating. The thickness of the wire will also affect the strength of the electromagnet, with thicker wire producing a stronger magnetic field.

2. What is the best way to wind the wire for a strong electromagnet?

The wire should be wound in a tight, even coil around a ferromagnetic core, such as iron or steel. The more turns of wire in the coil, the stronger the magnetic field will be. It is important to ensure that the wire is tightly wound and there are no gaps between each turn, as this will result in a weaker electromagnet.

3. How do I determine the appropriate power source for a strong electromagnet?

The power source for an electromagnet should be able to provide a high current, typically at least 5 amps. A direct current (DC) power supply is recommended, as it will allow for greater control and stability of the current. The voltage of the power source should also match the voltage rating of the wire used for the electromagnet.

4. Can I increase the strength of an electromagnet by adding more turns of wire?

Yes, the strength of an electromagnet can be increased by adding more turns of wire to the coil. However, there is a limit to how many turns can be added before the magnetic field reaches saturation and adding more turns will not result in a stronger electromagnet. It is important to find the balance between the number of turns and the thickness of the wire to create an optimal electromagnet.

5. How can I safely handle and control a strong electromagnet?

It is important to always handle a strong electromagnet with caution, as the magnetic field can be powerful and can attract or repel other objects. To control the strength of the electromagnet, a variable power supply or a variable resistor can be used to adjust the current flowing through the wire. It is also important to disconnect the power source when the electromagnet is not in use to avoid overheating and potential hazards.

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