Electromagnets Information

Electromagnets use electric current to generate a magnetic field which can be turned on or off as needed. They are made from a softer iron which quickly dissipates the induced magnetism after the current is switched off.  Electromagnetic strength is dependent on a variety of factors, such as the number of coils in the electrical wire that generates the power, the applied current, and the core material’s magnetic permeability. Categories of electromagnets include flat-faced, parallel pole, standard lifting, suspension, laboratory, and permanent.

Flat-faced electromagnets and parallel-pole magnets are two common types of electromagnets. Flat-faced magnets are used when the entire face of the magnet is in direct contact with a smooth, flat surface. Parallel-pole electromagnets or bi-polar magnets have two widely-spaced poles which allow the magnetic field to have a greater reach. These electromagnets are used when the magnet has only partial contact with the surface. They are also used to handle irregular shapes, or to work through an air gap.

Standard lifting magnets and suspension magnets are commonly available. Standard electromagnets are designed to lift sold, compact materials instead of scraps or small parts. Compact materials for standard lifting magnets include billets, steel plates, bars, and forgings. Suspension magnets are powerful electromagnets that are used for heavy or odd-shaped magnetic materials. These electromagnets are often used in process manufacturing, material handling, or scrap-yard use. 

Other types of electromagnets include laboratory electromagnets and permanent or electromagnet combinations. Laboratory electromagnets are used in research labs. Common configurations for these electromagnets are dipole, quadrupole, and sextuple electromagnets. Permanent or electromagnet combination magnets provide safe load-handling, even when power is accidentally removed from the target.

Electromagnets are used to lift and suspend objects in various applications, typically large amounts of ferrous materials such as scrap iron. Electromagnets are also used in the design of industrial and consumer products such as electric generators, electric motors, doorbells, circuit breakers, televisions, loudspeakers, brakes, and clutches. Special superconducting electromagnets generate powerful magnetic fields with little energy waste. Consequently, superconductor electromagnets are used in transportation applications, including space travel and maglev trains. Specialized electromagnets are also available from some electromagnet suppliers.

• Electromagnets Reject Residual Magnetism
  Electromagnets are designed with ejector pins to enable them to overcome the problems of residual magnetism occurring when power to the device is switched off. A new range of electromagnets from Geeplus have been designed with ejector pins to enable them to overcome the problems of residual...
• Slimmed-Down Magnetic-Bearing Systems Fit More Rotating Machinery Applications
  designed for a variety of industries. Where rolling-element bearings support shafts and other rotating components on balls or needles, magnetic bearings use stationary electromagnets positioned around the rotating components. Magnetic fields suspend the rotating parts within the bearings. Typically, two...
• The Switch to Switched Reluctance
  that of stepmotors because coils in the stator serve as electromagnets that attract the nearest rotor poles. One important difference between an SR motor and a stepper is that a stepper operates open loop. The rotor follows the magnetic field of the stator, but there is a possibility the two could get...