Fluorescent light bulbs need a ballast because they use a gas to create light. Regular light bulbs (also known as incandescent bulbs) create light by heating a filament inside the bulb. The heat makes the filament white-hot, producing the light that you see. In a fluorescent bulb, when the gas is excited by electricity, it emits invisible ultraviolet light that hits the white coating inside the fluorescent bulb. The coating changes the ultraviolet light into light you can see. (A lot of the energy used to create the heat that lights an incandescent bulb is wasted. Because fluorescent bulbs don't use heat to create light, they are far more energy-efficient than regular incandescent bulbs.)
The combination of gas, electricity, and coating in a fluorescent bulb is so effective at producing light that, without something to regulate the electricity flowing into the bulb, the light will continue to gain intensity until the bulb stops working. That's where a ballast comes in - it supplies the initial electricity that creates the light, and then it regulates the amount of electricity flowing through the bulb so that the right amount of light is emitted. What is a ballast, and how does one work? A ballast is an electrical component used with a fluorescent bulb (or mercury vapor lamp or arc lamp) to conduct electricity at each end of the tube. It supplies the initial electricity to the bulb that creates light, and then it regulates the amount of electricity flowing through the bulb so that it emits the right amount of light. [Non-text portions of this message have been removed]
