Controlling Magnetic Fields with Electromagnets
An electromagnet differs from any other magnet because its
magnetic field is created from the flow of electrical current. In order for the
magnet to work properly the current must be turned on. When turned off, the
magnetic field will diminish. These magnets are used in various applications
including automotives, junk yards, electronics, circuit breakers and many more.
A simple electromagnet can be easily made by wrapping some insulated copper
wire around an iron foundation and attaching a battery to the wire to create
the electric current. When the wire is connected to the battery, the iron will
become magnetized, when disconnected it will loose its magnetism. This is an
easy example of how electromagnets work, but every electromagnet works the same
way no matter how big or small the scale of the magnet is.
These magnets are often used in junk yards that receive old
cars that need to be crushed. Most of the cars do not work anymore and they can
not be driven to be moved. In order to move them a crane is used with an
electromagnetic head. The circuit is turned off until the crane head is
hovering over the car is wants to pick up. When the electric current is turned
on the car immediately attaches to the head of the crane through magnetic
force. While attached, the crane moves the car to where it needs go and the
electric current is turned off to release it to its destination. This is a
large scale example of how electromagnets are used, however they can also be
found in small applications such as speakers and television sets. These magnets
are very convenient because the magnetic field can be controlled. The only down
side is that electric energy is needed to create the magnetic field.
An electromagnet is a type of magnet that is composed of a battery and
iron wire that uses electric current in order to generate a magnetic
field. The magnetic field is generated when the electric current passes
through a wire, and the field dissipates when the current stops. The
primary function of electromagnets is that they are used to lift
metallic objects as well as being utilized in the design of many
different machines and electronic systems.
Scientific laboratories, manufacturing plants that handle scrap metal, the automotive industry and appliance and electronic manufacturers all benefit from the use of electromagnets. In addition, they are part of the design of electric motors, generators, doorbells, circuit breakers, TVs, speakers and read and write heads for hard disks and tape drives. In the automotive industry, electromagnets are used to manufacture brakes and clutches in vehicles. In factories and plants, electromagnets are used to lift and suspend scrap metal and other heavy metallic objects like billets, steel plates, bars and forgings. In many of these applications a permanent magnet can be used instead of an electromagnet; however, electromagnets offer the advantage of being able to manipulate the magnetic field over a wide range at a rapid pace.
There are a few main components that are utilized in the formation of electromagnets: a battery and an iron wire. This wire is often formed into a coil, and can be formed into various shapes including that of a helix, making it a solenoid coil and that of a donut-shape, making it a toroid coil. In addition, the material of iron is used as the wire component in electromagnets because it belongs to a small group of metals that exhibit ferromagnetic properties and generates a magnetic field when exposed to an electrical current. The magnetism only exists when current is flowing from the battery. This type of soft iron core is also referred to as a ferromagnetic core and offers extremely high magnetic permeability. There are two main types of electromagnets. The first, flat-fraud, is mainly used when the magnet is able to attach itself to a smooth, flat piece of metal. Parallel-pole electromagnets have two poles spaced far apart from each other that allow the magnetic field to have a greater reach. These are used when the metallic object is of an irregular shape and only comes in partial contact with the magnet surface.
More Electromagnets Information
Electromagnet - Adams Magnetic Products Co.
Electromagnet - Adams Magnetic Products Co.
Electromagnets Informational Video