Principle

After the solenoid is energized to produce a magnetic field such as a magnet bar. The circle in the figure for the wire section, point represents the current out of the screen, fork represents inflow screen; oval circle arrow is attached magnetic field lines. When a direct current through a conductor generates a magnetic field, and through the solenoid made (Solenoid) of the conductor bar magnets will produce a magnetic field similar. In the center of the solenoid adding a magnetic substance, this magnetic material is magnetized to achieve the effect of strong magnetic field. Drawer magnets Generally, the magnetic field strength generated by the electromagnet and the DC size, number of turns and the center of the magnetic material in the design of the coil of the electromagnet will focus on the distribution and guide the choice of iron material, and using direct current to control the size magnetic field strength. However, a material having a resistance of the coil of the electromagnet can restrict the magnetic field produced, but with the discovery and application of superconductors have the opportunity to break the current limit.