Here is a detailed article on ELECTRIC GUITARS HOW THEY WORK...
From somewhere around the 1950s the electric guitar has been linked with some of the greatest icons in music. It has played a very crucial role in the growth of today’s music. It is practically impossible to imagine rock music without the electric guitar.
The electric guitar is made of a solid or semi solid body. The concept behind how an electric guitar works is when you pluck the guitar’s strings, they produce vibrations, which get converted into electric current by the electro-magnetic pick-ups, which in turn transform the mechanical energy into electrical energy. Strings generate sound for the guitar by vibrating along their vibrating length. The guitar bridge on one end and the guitar nut on the other end fix the vibrating length of a guitar string. The strings are tied onto a guitar under tension.
What Influences The Sound Of An Electric Guitar? There are many elements that affect the quality or tone of the sound produced. These are:
The kind of wood and the way the guitar is made
The age and type of string used. A thicker string will vibrate more slowly.
The way the pickups are placed and combined
Cable length and quality
Playing environment and volume level
Basically four components influence the working of the guitar: The pickups, the volume knobs, tone knobs and pickup selector switch.
Pickups literally pick up the sound from the motion of the guitar strings by electromagnetic induction. The pickup has a magnet wrapped in fine copper wire. The magnet produces a magnetic field that can be focused across the strings. When a string is plucked, the vibration causes an electrical disturbance in the magnetic field, which gets passed on through the wire around the magnet to an amplifier.
With the volume knob, you can cut the entire output. There’s a potentiometer between the guitar pickup and the output to the amplifier. So when you turn the knob to increase volume, the entire signal bypasses the potentiometer, so there is no resistance. If you lower the knob, the amount of resistance goes up. Obviously, then, when the knob is turned all the way down, the signal will not reach the output.
Electric guitars built with humbucker pickups have higher value potentiometers than the ones with single coil pickups. Humbuckers produce larger signals because of the way in which their two coils are connected.
Tone knobs are also potentiometers placed on the side of the circuit and they work by cutting only the higher frequencies in the signal. Part of this signal is run to the electrical ground.
The Pick-Up Selector Switch
In guitars that have two pickups – for example a Les Paul, a 3-way switch selects both or one of the pickups. Guitars that have three pickups like the Stratocasters have a 5-way switch to select an individual pickup or combinations of pickups.
Apart from being the most popular instrument in music, the electric guitar is easy to carry around, adaptable, looks cool, sounds great, and suits almost any form and style of music.