Capacitors, which were previously known as condensers, are electrical components that store electric charge temporarily. Although capacitors may come in various shapes and sizes, they all have one function in common, storing electrical charge. The capacitor has two terminals that are separated by a non-conducting substance called dielectric. The dielectric can be made of film, paper plastic or air whereas the terminals can be made of aluminium or other conductive metals. One can even make capacitors at home by using two pieces of aluminium foil and a piece of paper. Although it would not be a good capacitor, it would still be able to function.
Although any non-conductive material can be classified as dielectric, only specific materials are used to construct capacitors depending how it will be applied. The dielectric can dictate what type of capacitor it would be and its application. The type and size of the dielectric used would determine the application of the capacitor. Some capacitors may be ideal for high frequency applications whereas others may be better at high voltage applications. They can be used for a variety of applications ranging from torch lights to huge capacitors that can power buses.
Capacitors that use air as a dielectric material in them can be used for radio tuning circuits. Capacitors using Mylar can be commonly found in timer circuits such as alarm clocks and glass and are often used as a dielectric material in capacitors that require high voltage applications. Applications that have high frequency such as x-ray or MRI make use of ceramic capacitors.
The amount of charge that a capacitor can store, which can also be called its capacitance, is measured in units called farads. A capacitor unlike a battery can take only a fraction of a second to completely discharge. A battery may however take minutes to do so. Due to this feature of capacitors, they are often used in the electronic flash on cameras. When you click a picture the flash come and goes off immediately. This is a good example of a capacitor discharging all its stored energy in a fraction of a second. When the flash is not clicked, the battery charges it up and it discharges this energy when a picture is clicked using flash. This however can be dangerous as capacitors such as those in television sets can contain large amount of charge. Therefore, if you were to open your TV set and touch the fully charged capacitor it could kill you.
Capacitors have definitely improved electronic devices tremendously and as well as aided in the advancement of technology greatly. However, when using electronic devices that have capacitors that can store a huge charge, one should always be very careful.Get More Information about capacitors.