Lighting ballasts provide the power behind the light, serving as both an inhibitor to limit the flow of current and as a conduit to supply the voltage and ignite the lamp.
Two main types of lighting ballasts are electromagnetic and electronic. Universal Manufacturing Corp. introduced its first electromagnetic ballasts in 1947. They have an electromagnetic core-and-coil transformer and operate the lamps at 60 hertz. They have a 12- to 15-year life span.
Introduced in 1967, electronic ballasts incorporate "smart" circuit components that provide improved light output and performance, are lighter in weight, operate cooler and provide greater energy-savings potential. They feature integrated circuit and feedback controls that can be used to dim lights, detect room occupancy and interface with energy management systems. While more expensive than electromagnetic ballasts, electronic ballasts have a longer life span, typically between 15 and 18 years.
"Electronic ballasts with T8 fluorescent lamps provide the greatest energy savings, a quick return on investment and improve working environments in new or existing lighting applications," says Janice Rewers of Universal Lighting Technologies.
Because of the significant energy savings that electronic ballasts offer and the desire to develop buildings that are energy efficient, the U.S. Department of Energy sponsored legislation that will eliminate the use of electromagnetic ballasts in lighting installations in the next decade. The law provides that effective in 2005, manufacturers must install only electronic ballasts in their systems. The same law applies to the replacement side of the business, but does not become effective until 2010.