Let us first begin down this winding path of coiled electronics by explaining what an inductor is. The construction of the inductor is from a piece of conductive wire–usually copper. The conductive property of wire is merely a term that is used for how well the free electrons of an element, in this case copper, is able to travel along the surface of the wire. The electricity travels on the surface of the wire. The better the conductor, the more the free electrons are allowed to flow.
This piece of copper wire is wound into a coil. The wire is generally insulated with a thin coating of lacquer, so when the wire touches against its coiled mate it does not short out.
When alternating current passes through the coil from one end of the wire to the other it creates a magnetic field. The alternating current, abbreviated as AC, that comes from your wall outlet is pulsing or alternating at 60 cycles per second. This means the electricity is literally going from plus 120 volts to minus 120 volts at 60 cycles per second. The cycle is also named a Hertz and is abbreviated as Hz.
Because the AC is generated at 60 Hz it can create a magnetic field when is passes through a piece of wire. This magnetic field cycles at 60 times a second. Because of the cycle going from positive to negative so rapidly it generally cancels itself out, or creates little force, in a straight piece of wire.
But if you wind that wire into a coil a strong magnetic field is produced. The field can be strong enough to move large objects if the coil is large and the field is powerful. A good example is the large Electro-magnetic cranes used in a salvage yard for lifting old cars or an electric motor. Every electric motor uses many coils of wire to create an induction of concentrated force to spin the motor shaft.
In fact, without the inductor you might not be able to read this article. Inductors are in use for your Cathode Ray Tube, abbreviated as CRT, in your computer monitor. The inductor creates a strong magnetic field that focuses the picture you are now seeing.
Electricity is generated by the use of huge inductors. These inductors are large copper bars that form coils. These bars rotate in strong fields of electromagnetic force; the result is the electricity we all use every day.
There are four basic types of inductors that are in common use today. In fact I am sure that you have many items in your home, office or business that utilize the versatile inductor.
1) Air core: this type is a simple wound coil of wire that is generally used for a small antenna to receive a radio signal for your home or car stereo.
2) Iron core: a coil that is wrapped around a solid piece of Iron rod and is used for audio reproduction i.e. the speakers that you listen to in your stereo.
3) Variable powdered iron core: this creates variable inductance and used to tune in your radio for your favorite station.
4) Iron core transformer: the large green transformer boxes in your alley, or the large cylindrical objects hanging on the power pole outside your home and business. These large coils transform the electricity from high voltage to what you get out of your outlet.
Without the inductor and the magnetic fields they produce from alternating current, our world would be a more difficult place to live. No electric motors, any lights, and no computers.