Light+Vocabulary!


 * AC (Alternating Current)**: Current which flows in one direction and then the other, alternately.


 * Arc**: Intense luminous discharge formed by the passage of electric current in a gaseous medium across a space between electrodes.


 * Alabaster**: genuine alabaster is a very fine variety of crystalline gypsum (hydrous calcium sulfate) found in nature. It is [|translucent] and its color is often white, pearly, or silky colorless but it, more often than not, has subtle reddish-brown bands of iron oxide running through it. It is often used for decorative objects such as light fixtures or figurines.


 * Ballast**: An auxiliary piece of equipment required to start and to properly control the flow of current to gas discharge light sources such as fluorescent and high intensity discharge lamps. Typically, magnetic ballasts (also called electromagnetic ballasts) contain copper windings on an iron core while electronic ballasts are smaller and more efficient and contain electronic components.


 * CCFL**: a cold cathode fluorescent lamp is a type of fluorescent lamp in which the cathode (an electron-emitting electrode inside the lamp) is not independently heated although the cathode can become quite hot once the CCFL has been operating.


 * Dimmer**: a device in an electrical circuit used for varying the brightness of lamps in a lighting installation. Dimming controls are ideal for almost any type of room because they can change the amount of lighting to suit each mood or activity and they can help you look good. The use of dimmers with incandescent, xenon, and halogen light sources also **//increases//** the life of the lamps and //**decreases**// the use of electrical energy.