Electromagnets
Magnetism by electric current
Electromagnets only become magnetic under the influence of an electrical current.
If you need a very strong and deep magnetic field, choose an electromagnet instead of a permanent magnet. The main advantage is that you can quickly turn off or change the magnetic field by controlling the amount of electric current in the windings.
Electromagnets generally consist of a core of ferromagnetic material, such as soft iron, around which a coil has been wound. The core is only magnetic as long as an electric current flows through the coil.
View the range of Goudsmit Magnetics electromagnets.