Fluorescent Bulbs and Ballasts

What is the difference between a regular light bulb and a fluorescent light bulb? 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 light. 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.

Why do fluorescent light bulbs need a ballast?
A ballast is an electrical component used with a fluorescent bulb to conduct electricity at each end of the tube. Fluorescent light bulbs need a ballast because they use a gas to create light. 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 makes compact fluorescent and fluorescent bulbs more energy-efficient than regular bulbs?
Fluorescent light bulbs, including compact fluorescents, are more energy-efficient than regular bulbs because of the different method they use to produce light. Regular bulbs create light by heating a filament inside the bulb; the heat makes the filament white-hot, producing light. A lot of the energy used to create the heat that lights an incandescent bulb is wasted. A fluorescent bulb, on the other hand, contains a gas that, when excited by electricity, hits a coating inside the fluorescent bulb and emits light. Because fluorescent bulbs don't use heat to create light, they are far more energy-efficient than regular incandescent bulbs.

Do fluorescent light bulbs give off hazardous amounts of ultraviolet (UV) light?
Regular fluorescent light bulbs used in your home and office do not produce a hazardous amount of ultraviolet light (UV). Most light sources, including fluorescent bulbs, emit a small amount of UV, but the UV produced by fluorescent light bulbs is far less than the amount produced by natural daylight.

What's the white powder I see inside my fluorescent bulb?
The white powder that you see inside a fluorescent lamp is called phosphor, which is a substance that emits white, visible light whenever it absorbs light waves. Both compact fluorescent bulbs and fluorescent tubes contain a gas that gives off invisible light when excited by electricity. This invisible light travels to the phosphor coating on the bulb, where it is transformed into light visible to the human eye.